Discussion:
WWVB Signal Generator
(too old to reply)
D. Resor
2018-08-25 11:33:58 UTC
Permalink
I thought I would search in a different way for a WWVB signal generator
design. I found this item. While the designer explains it isn't as
accurate as WWVB it may be another starting point.

http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-signal-generator.htm



Donald R. Resor Jr. T. W. & T. C. Svc. Co.
http://hammondorganservice.com
Hammond USA warranty service
"Most people don't have a sense of humor. They think they do, but they
don't." --Jonathan Winters

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Bob kb8tq
2018-08-25 16:04:09 UTC
Permalink
Hi

The question is - what’s the goal?

If this is just a way to keep clocks ticking within the roughly 0.1 seconds you can
see by eye, not a lot is needed. If it’s a device to drive Time Nuts sort of gear to
parts in ten to the bazilyionth, then things get a bit more complicated. Feed it
with it’s own GPS receiver or feed it with something else?

Lots of questions. No real need to answer them unless the budget does go through
with the shutdown in it. I suspect that the heart of a simple device can be done with a sub
$2 chip. GPS (obviously) would be on top of that cost.

Going closed source / mystery box ….. not for me !!!!

Bob

> On Aug 25, 2018, at 7:33 AM, D. Resor <***@pacbell.net> wrote:
>
> I thought I would search in a different way for a WWVB signal generator
> design. I found this item. While the designer explains it isn't as
> accurate as WWVB it may be another starting point.
>
> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-signal-generator.htm
>
>
>
> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> http://hammondorganservice.com
> Hammond USA warranty service
> "Most people don't have a sense of humor. They think they do, but they
> don't." --Jonathan Winters
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Mark Sims
2018-08-25 18:28:55 UTC
Permalink
If I was going to do it I would take a cheap Ublox 7M board (around $10 with antenna), program one of the time pulse outputs for 60 kHz (it divides evenly into 48 Mhz so no jitter), feed the Ublox serial data / 1PPS to an AVR chip (or $2 Arduino Nano clone), and use that to modulate the 60 KHz output. Total cost less than $20 and should get to to the microsecond level range.
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Vlad
2018-08-25 18:49:25 UTC
Permalink
Few moons ago, I was thinking about to connect little audio amp. with
attached usual WWVB ferrite antenna to the computer sound card. But I
was stack about how to modulate the signal using SoundCard libraries.
There is bunch of example how to generate sine or rectangles. The
question is how to make it works as WWVB


On 2018-08-25 14:28, Mark Sims wrote:
> If I was going to do it I would take a cheap Ublox 7M board (around
> $10 with antenna), program one of the time pulse outputs for 60 kHz
> (it divides evenly into 48 Mhz so no jitter), feed the Ublox serial
> data / 1PPS to an AVR chip (or $2 Arduino Nano clone), and use that
> to modulate the 60 KHz output. Total cost less than $20 and should
> get to to the microsecond level range.


--
WBW,

V.P.

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Peter Vince
2018-08-25 19:09:10 UTC
Permalink
Hi Mark,

If you were able to include optional modulation for the UK's MSF
signal as well as WWVB, then I'd be very interested - especially if you
could persuade John and TAPR to produce a kit :-) Europe's DCF would also
be a good selling point, but getting its 77.5KHz would be more difficult.

Peter


On 25 August 2018 at 19:28, Mark Sims <***@hotmail.com> wrote:

> If I was going to do it I would take a cheap Ublox 7M board (around $10
> with antenna), program one of the time pulse outputs for 60 kHz (it
> divides evenly into 48 Mhz so no jitter), feed the Ublox serial data /
> 1PPS to an AVR chip (or $2 Arduino Nano clone), and use that to modulate
> the 60 KHz output. Total cost less than $20 and should get to to the
> microsecond level range.
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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paul swed
2018-08-25 20:44:35 UTC
Permalink
Great to see the threads. Take a look at the Chronverter.
https://unusualelectronics.co.uk/products/chronvertor/
Its done all of this. I don't get anything by promoting Daves design. But
am having very good success with it on my Spectracom and Truetime clocks.
I would like to look at the code because I can already see some changes I
would like to do.
But all in all its very clever.
Regards
Paul
WB8TSL

On Sat, Aug 25, 2018 at 3:09 PM, Peter Vince <***@gmail.com>
wrote:

> Hi Mark,
>
> If you were able to include optional modulation for the UK's MSF
> signal as well as WWVB, then I'd be very interested - especially if you
> could persuade John and TAPR to produce a kit :-) Europe's DCF would also
> be a good selling point, but getting its 77.5KHz would be more difficult.
>
> Peter
>
>
> On 25 August 2018 at 19:28, Mark Sims <***@hotmail.com> wrote:
>
> > If I was going to do it I would take a cheap Ublox 7M board (around $10
> > with antenna), program one of the time pulse outputs for 60 kHz (it
> > divides evenly into 48 Mhz so no jitter), feed the Ublox serial data /
> > 1PPS to an AVR chip (or $2 Arduino Nano clone), and use that to modulate
> > the 60 KHz output. Total cost less than $20 and should get to to the
> > microsecond level range.
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
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>
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Wayne Holder
2018-08-26 01:09:57 UTC
Permalink
This guy has what looks like a well thought out design using a Sirf-Based
GPS and ATTiny44A chip to generate a signal to update his watch:

https://www.anishathalye.com/2016/12/26/micro-wwvb/

Unfortunately, he doesn't seem to have published a schematic or his source
code. But, he covers enough detail that I think it wouldn't be too hard to
replicate what he's done. Or, perhaps he would disclose these details if
contacted.

Wayne

On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net> wrote:

> I thought I would search in a different way for a WWVB signal generator
> design. I found this item. While the designer explains it isn't as
> accurate as WWVB it may be another starting point.
>
> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-signal-generator.htm
>
>
>
> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> http://hammondorganservice.com
> Hammond USA warranty service
> "Most people don't have a sense of humor. They think they do, but they
> don't." --Jonathan Winters
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Dana Whitlow
2018-08-26 02:29:13 UTC
Permalink
With the watch being physically close to the faux WWVB "transmitter", one
is in
the so-called "near field" regime, where the field strength (V/m) falls as
the inverse
cube of the distance. If one is putting the watch, say, within a few
inches of the
transmitter, reliable reception should be available yet the signal should
be literally
undetectable by any practical receiving device more than a few feet away.
Hence,
meeting the FCC field strength limit should be trivial.if the device is
used as pictured.
However, if one cranks up the power enough to reliably cover one's entire
house,
then there might be a problem depending how close the nearest neighbor
lives,
even at levels well within the FCC limit he quotes.

Taking the near field relationship in hand, 40 uV/m at 300m would translate
into
a whopping 0.135 V/m at 20 meters range, more than enough to feed most
peoples'
entire house. So the pragmatic issue would again be- neighbors. On the
other
hand, most of them would never be aware of the local signal as long as they
get good
time settings, unless they live close enough to Ft. Collins for the two
signals to
contend with each other.

It looks to me like the ferrite rod antenna is considerable overkill. Even
with no
purposeful antenna I'd expect leakage to yield sufficient signal for at
least a few
inches.

Dana


On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <***@gmail.com> wrote:

> This guy has what looks like a well thought out design using a Sirf-Based
> GPS and ATTiny44A chip to generate a signal to update his watch:
>
> https://www.anishathalye.com/2016/12/26/micro-wwvb/
>
> Unfortunately, he doesn't seem to have published a schematic or his source
> code. But, he covers enough detail that I think it wouldn't be too hard to
> replicate what he's done. Or, perhaps he would disclose these details if
> contacted.
>
> Wayne
>
> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net> wrote:
>
> > I thought I would search in a different way for a WWVB signal generator
> > design. I found this item. While the designer explains it isn't as
> > accurate as WWVB it may be another starting point.
> >
> > http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-signal-generator.htm
> >
> >
> >
> > Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > http://hammondorganservice.com
> > Hammond USA warranty service
> > "Most people don't have a sense of humor. They think they do, but they
> > don't." --Jonathan Winters
> >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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paul swed
2018-08-26 17:08:51 UTC
Permalink
Agree with the conversation. With respect to neighbors when the day comes
they may ask you to boost your signal. :-)
Granted maybe the day won't come but at least having your local clocks work
is nice.
Regards
Paul
WB8TSL

On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <***@gmail.com>
wrote:

> With the watch being physically close to the faux WWVB "transmitter", one
> is in
> the so-called "near field" regime, where the field strength (V/m) falls as
> the inverse
> cube of the distance. If one is putting the watch, say, within a few
> inches of the
> transmitter, reliable reception should be available yet the signal should
> be literally
> undetectable by any practical receiving device more than a few feet away.
> Hence,
> meeting the FCC field strength limit should be trivial.if the device is
> used as pictured.
> However, if one cranks up the power enough to reliably cover one's entire
> house,
> then there might be a problem depending how close the nearest neighbor
> lives,
> even at levels well within the FCC limit he quotes.
>
> Taking the near field relationship in hand, 40 uV/m at 300m would translate
> into
> a whopping 0.135 V/m at 20 meters range, more than enough to feed most
> peoples'
> entire house. So the pragmatic issue would again be- neighbors. On the
> other
> hand, most of them would never be aware of the local signal as long as they
> get good
> time settings, unless they live close enough to Ft. Collins for the two
> signals to
> contend with each other.
>
> It looks to me like the ferrite rod antenna is considerable overkill. Even
> with no
> purposeful antenna I'd expect leakage to yield sufficient signal for at
> least a few
> inches.
>
> Dana
>
>
> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <***@gmail.com>
> wrote:
>
> > This guy has what looks like a well thought out design using a Sirf-Based
> > GPS and ATTiny44A chip to generate a signal to update his watch:
> >
> > https://www.anishathalye.com/2016/12/26/micro-wwvb/
> >
> > Unfortunately, he doesn't seem to have published a schematic or his
> source
> > code. But, he covers enough detail that I think it wouldn't be too hard
> to
> > replicate what he's done. Or, perhaps he would disclose these details if
> > contacted.
> >
> > Wayne
> >
> > On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
> wrote:
> >
> > > I thought I would search in a different way for a WWVB signal generator
> > > design. I found this item. While the designer explains it isn't as
> > > accurate as WWVB it may be another starting point.
> > >
> > > http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-signal-generator.htm
> > >
> > >
> > >
> > > Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > > http://hammondorganservice.com
> > > Hammond USA warranty service
> > > "Most people don't have a sense of humor. They think they do, but they
> > > don't." --Jonathan Winters
> > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to
> > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Bob kb8tq
2018-08-26 18:34:42 UTC
Permalink
Hi

The gotcha is if you have neighbors two or three doors away that *also* put up one of
these devices. You then have a real problem with the neighbor(s) in the middle. The
wavelength is long enough that Raleigh issues won’t get you. You still have the two
signals ( at slightly different frequencies) beating against each other. The result is
going to show up as who knows what to this or that receiver. With a precision receiver,
you might even have issues from the guy two houses away …...

Bob

> On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
>
> Agree with the conversation. With respect to neighbors when the day comes
> they may ask you to boost your signal. :-)
> Granted maybe the day won't come but at least having your local clocks work
> is nice.
> Regards
> Paul
> WB8TSL
>
> On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <***@gmail.com>
> wrote:
>
>> With the watch being physically close to the faux WWVB "transmitter", one
>> is in
>> the so-called "near field" regime, where the field strength (V/m) falls as
>> the inverse
>> cube of the distance. If one is putting the watch, say, within a few
>> inches of the
>> transmitter, reliable reception should be available yet the signal should
>> be literally
>> undetectable by any practical receiving device more than a few feet away.
>> Hence,
>> meeting the FCC field strength limit should be trivial.if the device is
>> used as pictured.
>> However, if one cranks up the power enough to reliably cover one's entire
>> house,
>> then there might be a problem depending how close the nearest neighbor
>> lives,
>> even at levels well within the FCC limit he quotes.
>>
>> Taking the near field relationship in hand, 40 uV/m at 300m would translate
>> into
>> a whopping 0.135 V/m at 20 meters range, more than enough to feed most
>> peoples'
>> entire house. So the pragmatic issue would again be- neighbors. On the
>> other
>> hand, most of them would never be aware of the local signal as long as they
>> get good
>> time settings, unless they live close enough to Ft. Collins for the two
>> signals to
>> contend with each other.
>>
>> It looks to me like the ferrite rod antenna is considerable overkill. Even
>> with no
>> purposeful antenna I'd expect leakage to yield sufficient signal for at
>> least a few
>> inches.
>>
>> Dana
>>
>>
>> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <***@gmail.com>
>> wrote:
>>
>>> This guy has what looks like a well thought out design using a Sirf-Based
>>> GPS and ATTiny44A chip to generate a signal to update his watch:
>>>
>>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
>>>
>>> Unfortunately, he doesn't seem to have published a schematic or his
>> source
>>> code. But, he covers enough detail that I think it wouldn't be too hard
>> to
>>> replicate what he's done. Or, perhaps he would disclose these details if
>>> contacted.
>>>
>>> Wayne
>>>
>>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
>> wrote:
>>>
>>>> I thought I would search in a different way for a WWVB signal generator
>>>> design. I found this item. While the designer explains it isn't as
>>>> accurate as WWVB it may be another starting point.
>>>>
>>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-signal-generator.htm
>>>>
>>>>
>>>>
>>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
>>>> http://hammondorganservice.com
>>>> Hammond USA warranty service
>>>> "Most people don't have a sense of humor. They think they do, but they
>>>> don't." --Jonathan Winters
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to
>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/
>> listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
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paul swed
2018-08-26 21:51:05 UTC
Permalink
That would be a great neighbor to have but I can tell you around here its
the phone. Not to concerned about someone putting up a wwvb replacement.
And I can always up the power. Chickle.
Regards
Paul

On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:

> Hi
>
> The gotcha is if you have neighbors two or three doors away that *also*
> put up one of
> these devices. You then have a real problem with the neighbor(s) in the
> middle. The
> wavelength is long enough that Raleigh issues won’t get you. You still
> have the two
> signals ( at slightly different frequencies) beating against each other.
> The result is
> going to show up as who knows what to this or that receiver. With a
> precision receiver,
> you might even have issues from the guy two houses away …...
>
> Bob
>
> > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
> >
> > Agree with the conversation. With respect to neighbors when the day comes
> > they may ask you to boost your signal. :-)
> > Granted maybe the day won't come but at least having your local clocks
> work
> > is nice.
> > Regards
> > Paul
> > WB8TSL
> >
> > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <***@gmail.com>
> > wrote:
> >
> >> With the watch being physically close to the faux WWVB "transmitter",
> one
> >> is in
> >> the so-called "near field" regime, where the field strength (V/m) falls
> as
> >> the inverse
> >> cube of the distance. If one is putting the watch, say, within a few
> >> inches of the
> >> transmitter, reliable reception should be available yet the signal
> should
> >> be literally
> >> undetectable by any practical receiving device more than a few feet
> away.
> >> Hence,
> >> meeting the FCC field strength limit should be trivial.if the device is
> >> used as pictured.
> >> However, if one cranks up the power enough to reliably cover one's
> entire
> >> house,
> >> then there might be a problem depending how close the nearest neighbor
> >> lives,
> >> even at levels well within the FCC limit he quotes.
> >>
> >> Taking the near field relationship in hand, 40 uV/m at 300m would
> translate
> >> into
> >> a whopping 0.135 V/m at 20 meters range, more than enough to feed most
> >> peoples'
> >> entire house. So the pragmatic issue would again be- neighbors. On the
> >> other
> >> hand, most of them would never be aware of the local signal as long as
> they
> >> get good
> >> time settings, unless they live close enough to Ft. Collins for the two
> >> signals to
> >> contend with each other.
> >>
> >> It looks to me like the ferrite rod antenna is considerable overkill.
> Even
> >> with no
> >> purposeful antenna I'd expect leakage to yield sufficient signal for at
> >> least a few
> >> inches.
> >>
> >> Dana
> >>
> >>
> >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <***@gmail.com>
> >> wrote:
> >>
> >>> This guy has what looks like a well thought out design using a
> Sirf-Based
> >>> GPS and ATTiny44A chip to generate a signal to update his watch:
> >>>
> >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> >>>
> >>> Unfortunately, he doesn't seem to have published a schematic or his
> >> source
> >>> code. But, he covers enough detail that I think it wouldn't be too
> hard
> >> to
> >>> replicate what he's done. Or, perhaps he would disclose these details
> if
> >>> contacted.
> >>>
> >>> Wayne
> >>>
> >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
> >> wrote:
> >>>
> >>>> I thought I would search in a different way for a WWVB signal
> generator
> >>>> design. I found this item. While the designer explains it isn't as
> >>>> accurate as WWVB it may be another starting point.
> >>>>
> >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> signal-generator.htm
> >>>>
> >>>>
> >>>>
> >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> >>>> http://hammondorganservice.com
> >>>> Hammond USA warranty service
> >>>> "Most people don't have a sense of humor. They think they do, but they
> >>>> don't." --Jonathan Winters
> >>>>
> >>>> _______________________________________________
> >>>> time-nuts mailing list -- time-***@lists.febo.com
> >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> >>>> listinfo/time-nuts_lists.febo.com
> >>>> and follow the instructions there.
> >>>>
> >>> _______________________________________________
> >>> time-nuts mailing list -- time-***@lists.febo.com
> >>> To unsubscribe, go to
> >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> >>> and follow the instructions there.
> >>>
> >> _______________________________________________
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> >> To unsubscribe, go to http://lists.febo.com/mailman/
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> >> and follow the instructions there.
> >>
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> > and follow the instructions there.
>
>
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an
Wayne Holder
2018-08-29 08:35:37 UTC
Permalink
As a follow up, I now have a simple WWVB simulator written in C that's now
running an an ATTiny85 using nothing more than the internal, 8
mHz oscillator and about a 6 inch length of wire connected to one of the
pins as an antenna. It generates an approximate 60 kHz signal using PWM on
timer 1. I tweaked the timer value a bit to correct for some variance in
the internal oscillator, but I' not even sure that was necessary, as my
target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
Modulation is done by varying the duty cycle of the PWM to approximate the
-17 dBr drop on the carrier. But, again, I don't think this value is
critical with a consumer clock chip. I tapped the demodulated output
inside the clock and displayed it on my scope along with the generated
signal and I got good, steady demodulation with the wire antenna just
placed near clock. The next step is to connect up a GPS module and add
code to use it to set the time. I'm also going to change the code to use
the PPS signal from the GPS to drive the output timing rather than the test
code I have now that uses timer 0 to generate the PPS interrupt. I'm happy
to share details if anyone is interested.

Wayne



On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com> wrote:

> That would be a great neighbor to have but I can tell you around here its
> the phone. Not to concerned about someone putting up a wwvb replacement.
> And I can always up the power. Chickle.
> Regards
> Paul
>
> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
>
> > Hi
> >
> > The gotcha is if you have neighbors two or three doors away that *also*
> > put up one of
> > these devices. You then have a real problem with the neighbor(s) in the
> > middle. The
> > wavelength is long enough that Raleigh issues won’t get you. You still
> > have the two
> > signals ( at slightly different frequencies) beating against each other.
> > The result is
> > going to show up as who knows what to this or that receiver. With a
> > precision receiver,
> > you might even have issues from the guy two houses away …...
> >
> > Bob
> >
> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
> > >
> > > Agree with the conversation. With respect to neighbors when the day
> comes
> > > they may ask you to boost your signal. :-)
> > > Granted maybe the day won't come but at least having your local clocks
> > work
> > > is nice.
> > > Regards
> > > Paul
> > > WB8TSL
> > >
> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <***@gmail.com>
> > > wrote:
> > >
> > >> With the watch being physically close to the faux WWVB "transmitter",
> > one
> > >> is in
> > >> the so-called "near field" regime, where the field strength (V/m)
> falls
> > as
> > >> the inverse
> > >> cube of the distance. If one is putting the watch, say, within a few
> > >> inches of the
> > >> transmitter, reliable reception should be available yet the signal
> > should
> > >> be literally
> > >> undetectable by any practical receiving device more than a few feet
> > away.
> > >> Hence,
> > >> meeting the FCC field strength limit should be trivial.if the device
> is
> > >> used as pictured.
> > >> However, if one cranks up the power enough to reliably cover one's
> > entire
> > >> house,
> > >> then there might be a problem depending how close the nearest neighbor
> > >> lives,
> > >> even at levels well within the FCC limit he quotes.
> > >>
> > >> Taking the near field relationship in hand, 40 uV/m at 300m would
> > translate
> > >> into
> > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed most
> > >> peoples'
> > >> entire house. So the pragmatic issue would again be- neighbors. On
> the
> > >> other
> > >> hand, most of them would never be aware of the local signal as long as
> > they
> > >> get good
> > >> time settings, unless they live close enough to Ft. Collins for the
> two
> > >> signals to
> > >> contend with each other.
> > >>
> > >> It looks to me like the ferrite rod antenna is considerable overkill.
> > Even
> > >> with no
> > >> purposeful antenna I'd expect leakage to yield sufficient signal for
> at
> > >> least a few
> > >> inches.
> > >>
> > >> Dana
> > >>
> > >>
> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <***@gmail.com>
> > >> wrote:
> > >>
> > >>> This guy has what looks like a well thought out design using a
> > Sirf-Based
> > >>> GPS and ATTiny44A chip to generate a signal to update his watch:
> > >>>
> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> > >>>
> > >>> Unfortunately, he doesn't seem to have published a schematic or his
> > >> source
> > >>> code. But, he covers enough detail that I think it wouldn't be too
> > hard
> > >> to
> > >>> replicate what he's done. Or, perhaps he would disclose these
> details
> > if
> > >>> contacted.
> > >>>
> > >>> Wayne
> > >>>
> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
> > >> wrote:
> > >>>
> > >>>> I thought I would search in a different way for a WWVB signal
> > generator
> > >>>> design. I found this item. While the designer explains it isn't as
> > >>>> accurate as WWVB it may be another starting point.
> > >>>>
> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> > signal-generator.htm
> > >>>>
> > >>>>
> > >>>>
> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > >>>> http://hammondorganservice.com
> > >>>> Hammond USA warranty service
> > >>>> "Most people don't have a sense of humor. They think they do, but
> they
> > >>>> don't." --Jonathan Winters
> > >>>>
> > >>>> _______________________________________________
> > >>>> time-nuts mailing list -- time-***@lists.febo.com
> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> > >>>> listinfo/time-nuts_lists.febo.com
> > >>>> and follow the instructions there.
> > >>>>
> > >>> _______________________________________________
> > >>> time-nuts mailing list -- time-***@lists.febo.com
> > >>> To unsubscribe, go to
> > >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > >>> and follow the instructions there.
> > >>>
> > >> _______________________________________________
> > >> time-nuts mailing list -- time-***@lists.febo.com
> > >> To unsubscribe, go to http://lists.febo.com/mailman/
> > >> listinfo/time-nuts_lists.febo.com
> > >> and follow the instructions there.
> > >>
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
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Dana Whitlow
2018-08-29 08:55:20 UTC
Permalink
I hope that those of you who write code to generate the WWVB signals in real
time from a GPS receiver's output will publish well documented source
listings.

I for one want to learn how one does this kind of thing in 'C', both for
general
interest and for this specific application.

Thanks,

Dana



On Wed, Aug 29, 2018 at 3:36 AM Wayne Holder <***@gmail.com> wrote:

> As a follow up, I now have a simple WWVB simulator written in C that's now
> running an an ATTiny85 using nothing more than the internal, 8
> mHz oscillator and about a 6 inch length of wire connected to one of the
> pins as an antenna. It generates an approximate 60 kHz signal using PWM on
> timer 1. I tweaked the timer value a bit to correct for some variance in
> the internal oscillator, but I' not even sure that was necessary, as my
> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
> Modulation is done by varying the duty cycle of the PWM to approximate the
> -17 dBr drop on the carrier. But, again, I don't think this value is
> critical with a consumer clock chip. I tapped the demodulated output
> inside the clock and displayed it on my scope along with the generated
> signal and I got good, steady demodulation with the wire antenna just
> placed near clock. The next step is to connect up a GPS module and add
> code to use it to set the time. I'm also going to change the code to use
> the PPS signal from the GPS to drive the output timing rather than the test
> code I have now that uses timer 0 to generate the PPS interrupt. I'm happy
> to share details if anyone is interested.
>
> Wayne
>
>
>
> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com> wrote:
>
> > That would be a great neighbor to have but I can tell you around here its
> > the phone. Not to concerned about someone putting up a wwvb replacement.
> > And I can always up the power. Chickle.
> > Regards
> > Paul
> >
> > On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
> >
> > > Hi
> > >
> > > The gotcha is if you have neighbors two or three doors away that *also*
> > > put up one of
> > > these devices. You then have a real problem with the neighbor(s) in the
> > > middle. The
> > > wavelength is long enough that Raleigh issues won’t get you. You still
> > > have the two
> > > signals ( at slightly different frequencies) beating against each
> other.
> > > The result is
> > > going to show up as who knows what to this or that receiver. With a
> > > precision receiver,
> > > you might even have issues from the guy two houses away …...
> > >
> > > Bob
> > >
> > > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
> > > >
> > > > Agree with the conversation. With respect to neighbors when the day
> > comes
> > > > they may ask you to boost your signal. :-)
> > > > Granted maybe the day won't come but at least having your local
> clocks
> > > work
> > > > is nice.
> > > > Regards
> > > > Paul
> > > > WB8TSL
> > > >
> > > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> ***@gmail.com>
> > > > wrote:
> > > >
> > > >> With the watch being physically close to the faux WWVB
> "transmitter",
> > > one
> > > >> is in
> > > >> the so-called "near field" regime, where the field strength (V/m)
> > falls
> > > as
> > > >> the inverse
> > > >> cube of the distance. If one is putting the watch, say, within a
> few
> > > >> inches of the
> > > >> transmitter, reliable reception should be available yet the signal
> > > should
> > > >> be literally
> > > >> undetectable by any practical receiving device more than a few feet
> > > away.
> > > >> Hence,
> > > >> meeting the FCC field strength limit should be trivial.if the device
> > is
> > > >> used as pictured.
> > > >> However, if one cranks up the power enough to reliably cover one's
> > > entire
> > > >> house,
> > > >> then there might be a problem depending how close the nearest
> neighbor
> > > >> lives,
> > > >> even at levels well within the FCC limit he quotes.
> > > >>
> > > >> Taking the near field relationship in hand, 40 uV/m at 300m would
> > > translate
> > > >> into
> > > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed
> most
> > > >> peoples'
> > > >> entire house. So the pragmatic issue would again be- neighbors. On
> > the
> > > >> other
> > > >> hand, most of them would never be aware of the local signal as long
> as
> > > they
> > > >> get good
> > > >> time settings, unless they live close enough to Ft. Collins for the
> > two
> > > >> signals to
> > > >> contend with each other.
> > > >>
> > > >> It looks to me like the ferrite rod antenna is considerable
> overkill.
> > > Even
> > > >> with no
> > > >> purposeful antenna I'd expect leakage to yield sufficient signal for
> > at
> > > >> least a few
> > > >> inches.
> > > >>
> > > >> Dana
> > > >>
> > > >>
> > > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> ***@gmail.com>
> > > >> wrote:
> > > >>
> > > >>> This guy has what looks like a well thought out design using a
> > > Sirf-Based
> > > >>> GPS and ATTiny44A chip to generate a signal to update his watch:
> > > >>>
> > > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> > > >>>
> > > >>> Unfortunately, he doesn't seem to have published a schematic or his
> > > >> source
> > > >>> code. But, he covers enough detail that I think it wouldn't be too
> > > hard
> > > >> to
> > > >>> replicate what he's done. Or, perhaps he would disclose these
> > details
> > > if
> > > >>> contacted.
> > > >>>
> > > >>> Wayne
> > > >>>
> > > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
> > > >> wrote:
> > > >>>
> > > >>>> I thought I would search in a different way for a WWVB signal
> > > generator
> > > >>>> design. I found this item. While the designer explains it isn't
> as
> > > >>>> accurate as WWVB it may be another starting point.
> > > >>>>
> > > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> > > signal-generator.htm
> > > >>>>
> > > >>>>
> > > >>>>
> > > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > > >>>> http://hammondorganservice.com
> > > >>>> Hammond USA warranty service
> > > >>>> "Most people don't have a sense of humor. They think they do, but
> > they
> > > >>>> don't." --Jonathan Winters
> > > >>>>
> > > >>>> _______________________________________________
> > > >>>> time-nuts mailing list -- time-***@lists.febo.com
> > > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> > > >>>> listinfo/time-nuts_lists.febo.com
> > > >>>> and follow the instructions there.
> > > >>>>
> > > >>> _______________________________________________
> > > >>> time-nuts mailing list -- time-***@lists.febo.com
> > > >>> To unsubscribe, go to
> > > >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > >>> and follow the instructions there.
> > > >>>
> > > >> _______________________________________________
> > > >> time-nuts mailing list -- time-***@lists.febo.com
> > > >> To unsubscribe, go to http://lists.febo.com/mailman/
> > > >> listinfo/time-nuts_lists.febo.com
> > > >> and follow the instructions there.
> > > >>
> > > > _______________________________________________
> > > > time-nuts mailing list -- time-***@lists.febo.com
> > > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > > and follow the instructions there.
> > >
> > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
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Bob kb8tq
2018-08-29 15:59:39 UTC
Permalink
Hi

If somebody really wanted to go crazy on this, a link just popped up in my inbox:

https://www.st.com/content/st_com/en/about/events/events.html/teseo-liv3f-gnss-module-webinar.html?ecmp=tt7108_us_enews_apr2018&cid=stmDM10269&bid=166175037&uid=tEVjzOAFGOno6x6Htwrh8A== <https://www.st.com/content/st_com/en/about/events/events.html/teseo-liv3f-gnss-module-webinar.html?ecmp=tt7108_us_enews_apr2018&cid=stmDM10269&bid=166175037&uid=tEVjzOAFGOno6x6Htwrh8A==>

I know zip about the ST chips other than what’s in the link. The webinar is free and at least
that’s better than signing an NDA simply to look at the slides ( which some other vendors seem
to want you to do).

Bob

> On Aug 29, 2018, at 4:55 AM, Dana Whitlow <***@gmail.com> wrote:
>
> I hope that those of you who write code to generate the WWVB signals in real
> time from a GPS receiver's output will publish well documented source
> listings.
>
> I for one want to learn how one does this kind of thing in 'C', both for
> general
> interest and for this specific application.
>
> Thanks,
>
> Dana
>
>
>
> On Wed, Aug 29, 2018 at 3:36 AM Wayne Holder <***@gmail.com> wrote:
>
>> As a follow up, I now have a simple WWVB simulator written in C that's now
>> running an an ATTiny85 using nothing more than the internal, 8
>> mHz oscillator and about a 6 inch length of wire connected to one of the
>> pins as an antenna. It generates an approximate 60 kHz signal using PWM on
>> timer 1. I tweaked the timer value a bit to correct for some variance in
>> the internal oscillator, but I' not even sure that was necessary, as my
>> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
>> Modulation is done by varying the duty cycle of the PWM to approximate the
>> -17 dBr drop on the carrier. But, again, I don't think this value is
>> critical with a consumer clock chip. I tapped the demodulated output
>> inside the clock and displayed it on my scope along with the generated
>> signal and I got good, steady demodulation with the wire antenna just
>> placed near clock. The next step is to connect up a GPS module and add
>> code to use it to set the time. I'm also going to change the code to use
>> the PPS signal from the GPS to drive the output timing rather than the test
>> code I have now that uses timer 0 to generate the PPS interrupt. I'm happy
>> to share details if anyone is interested.
>>
>> Wayne
>>
>>
>>
>> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com> wrote:
>>
>>> That would be a great neighbor to have but I can tell you around here its
>>> the phone. Not to concerned about someone putting up a wwvb replacement.
>>> And I can always up the power. Chickle.
>>> Regards
>>> Paul
>>>
>>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
>>>
>>>> Hi
>>>>
>>>> The gotcha is if you have neighbors two or three doors away that *also*
>>>> put up one of
>>>> these devices. You then have a real problem with the neighbor(s) in the
>>>> middle. The
>>>> wavelength is long enough that Raleigh issues won’t get you. You still
>>>> have the two
>>>> signals ( at slightly different frequencies) beating against each
>> other.
>>>> The result is
>>>> going to show up as who knows what to this or that receiver. With a
>>>> precision receiver,
>>>> you might even have issues from the guy two houses away …...
>>>>
>>>> Bob
>>>>
>>>>> On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
>>>>>
>>>>> Agree with the conversation. With respect to neighbors when the day
>>> comes
>>>>> they may ask you to boost your signal. :-)
>>>>> Granted maybe the day won't come but at least having your local
>> clocks
>>>> work
>>>>> is nice.
>>>>> Regards
>>>>> Paul
>>>>> WB8TSL
>>>>>
>>>>> On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
>> ***@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> With the watch being physically close to the faux WWVB
>> "transmitter",
>>>> one
>>>>>> is in
>>>>>> the so-called "near field" regime, where the field strength (V/m)
>>> falls
>>>> as
>>>>>> the inverse
>>>>>> cube of the distance. If one is putting the watch, say, within a
>> few
>>>>>> inches of the
>>>>>> transmitter, reliable reception should be available yet the signal
>>>> should
>>>>>> be literally
>>>>>> undetectable by any practical receiving device more than a few feet
>>>> away.
>>>>>> Hence,
>>>>>> meeting the FCC field strength limit should be trivial.if the device
>>> is
>>>>>> used as pictured.
>>>>>> However, if one cranks up the power enough to reliably cover one's
>>>> entire
>>>>>> house,
>>>>>> then there might be a problem depending how close the nearest
>> neighbor
>>>>>> lives,
>>>>>> even at levels well within the FCC limit he quotes.
>>>>>>
>>>>>> Taking the near field relationship in hand, 40 uV/m at 300m would
>>>> translate
>>>>>> into
>>>>>> a whopping 0.135 V/m at 20 meters range, more than enough to feed
>> most
>>>>>> peoples'
>>>>>> entire house. So the pragmatic issue would again be- neighbors. On
>>> the
>>>>>> other
>>>>>> hand, most of them would never be aware of the local signal as long
>> as
>>>> they
>>>>>> get good
>>>>>> time settings, unless they live close enough to Ft. Collins for the
>>> two
>>>>>> signals to
>>>>>> contend with each other.
>>>>>>
>>>>>> It looks to me like the ferrite rod antenna is considerable
>> overkill.
>>>> Even
>>>>>> with no
>>>>>> purposeful antenna I'd expect leakage to yield sufficient signal for
>>> at
>>>>>> least a few
>>>>>> inches.
>>>>>>
>>>>>> Dana
>>>>>>
>>>>>>
>>>>>> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
>> ***@gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> This guy has what looks like a well thought out design using a
>>>> Sirf-Based
>>>>>>> GPS and ATTiny44A chip to generate a signal to update his watch:
>>>>>>>
>>>>>>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
>>>>>>>
>>>>>>> Unfortunately, he doesn't seem to have published a schematic or his
>>>>>> source
>>>>>>> code. But, he covers enough detail that I think it wouldn't be too
>>>> hard
>>>>>> to
>>>>>>> replicate what he's done. Or, perhaps he would disclose these
>>> details
>>>> if
>>>>>>> contacted.
>>>>>>>
>>>>>>> Wayne
>>>>>>>
>>>>>>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
>>>>>> wrote:
>>>>>>>
>>>>>>>> I thought I would search in a different way for a WWVB signal
>>>> generator
>>>>>>>> design. I found this item. While the designer explains it isn't
>> as
>>>>>>>> accurate as WWVB it may be another starting point.
>>>>>>>>
>>>>>>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
>>>> signal-generator.htm
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
>>>>>>>> http://hammondorganservice.com
>>>>>>>> Hammond USA warranty service
>>>>>>>> "Most people don't have a sense of humor. They think they do, but
>>> they
>>>>>>>> don't." --Jonathan Winters
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>>>>>> listinfo/time-nuts_lists.febo.com
>>>>>>>> and follow the instructions there.
>>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>>>> To unsubscribe, go to
>>>>>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>>>>>> and follow the instructions there.
>>>>>>>
>>>>>> _______________________________________________
>>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>>>> listinfo/time-nuts_lists.febo.com
>>>>>> and follow the instructions there.
>>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>>> and follow the instructions there.
>>>>
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>> listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>>
>> _______________________________________________
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>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
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and follo
paul swed
2018-08-29 15:32:48 UTC
Permalink
Wayne always fun to see what others are doing and to learn.
I would imagine the programs pretty small and could be attached here.
How will you handle DST? Its a bit messy as a recent thread detailed.
Plus the fact that god knows why politicians like to screw with it.
Regards
Paul
WB8TSL

On Wed, Aug 29, 2018 at 4:35 AM, Wayne Holder <***@gmail.com>
wrote:

> As a follow up, I now have a simple WWVB simulator written in C that's now
> running an an ATTiny85 using nothing more than the internal, 8
> mHz oscillator and about a 6 inch length of wire connected to one of the
> pins as an antenna. It generates an approximate 60 kHz signal using PWM on
> timer 1. I tweaked the timer value a bit to correct for some variance in
> the internal oscillator, but I' not even sure that was necessary, as my
> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
> Modulation is done by varying the duty cycle of the PWM to approximate the
> -17 dBr drop on the carrier. But, again, I don't think this value is
> critical with a consumer clock chip. I tapped the demodulated output
> inside the clock and displayed it on my scope along with the generated
> signal and I got good, steady demodulation with the wire antenna just
> placed near clock. The next step is to connect up a GPS module and add
> code to use it to set the time. I'm also going to change the code to use
> the PPS signal from the GPS to drive the output timing rather than the test
> code I have now that uses timer 0 to generate the PPS interrupt. I'm happy
> to share details if anyone is interested.
>
> Wayne
>
>
>
> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com> wrote:
>
> > That would be a great neighbor to have but I can tell you around here its
> > the phone. Not to concerned about someone putting up a wwvb replacement.
> > And I can always up the power. Chickle.
> > Regards
> > Paul
> >
> > On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
> >
> > > Hi
> > >
> > > The gotcha is if you have neighbors two or three doors away that *also*
> > > put up one of
> > > these devices. You then have a real problem with the neighbor(s) in the
> > > middle. The
> > > wavelength is long enough that Raleigh issues won’t get you. You still
> > > have the two
> > > signals ( at slightly different frequencies) beating against each
> other.
> > > The result is
> > > going to show up as who knows what to this or that receiver. With a
> > > precision receiver,
> > > you might even have issues from the guy two houses away …...
> > >
> > > Bob
> > >
> > > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
> > > >
> > > > Agree with the conversation. With respect to neighbors when the day
> > comes
> > > > they may ask you to boost your signal. :-)
> > > > Granted maybe the day won't come but at least having your local
> clocks
> > > work
> > > > is nice.
> > > > Regards
> > > > Paul
> > > > WB8TSL
> > > >
> > > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> ***@gmail.com>
> > > > wrote:
> > > >
> > > >> With the watch being physically close to the faux WWVB
> "transmitter",
> > > one
> > > >> is in
> > > >> the so-called "near field" regime, where the field strength (V/m)
> > falls
> > > as
> > > >> the inverse
> > > >> cube of the distance. If one is putting the watch, say, within a
> few
> > > >> inches of the
> > > >> transmitter, reliable reception should be available yet the signal
> > > should
> > > >> be literally
> > > >> undetectable by any practical receiving device more than a few feet
> > > away.
> > > >> Hence,
> > > >> meeting the FCC field strength limit should be trivial.if the device
> > is
> > > >> used as pictured.
> > > >> However, if one cranks up the power enough to reliably cover one's
> > > entire
> > > >> house,
> > > >> then there might be a problem depending how close the nearest
> neighbor
> > > >> lives,
> > > >> even at levels well within the FCC limit he quotes.
> > > >>
> > > >> Taking the near field relationship in hand, 40 uV/m at 300m would
> > > translate
> > > >> into
> > > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed
> most
> > > >> peoples'
> > > >> entire house. So the pragmatic issue would again be- neighbors. On
> > the
> > > >> other
> > > >> hand, most of them would never be aware of the local signal as long
> as
> > > they
> > > >> get good
> > > >> time settings, unless they live close enough to Ft. Collins for the
> > two
> > > >> signals to
> > > >> contend with each other.
> > > >>
> > > >> It looks to me like the ferrite rod antenna is considerable
> overkill.
> > > Even
> > > >> with no
> > > >> purposeful antenna I'd expect leakage to yield sufficient signal for
> > at
> > > >> least a few
> > > >> inches.
> > > >>
> > > >> Dana
> > > >>
> > > >>
> > > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> ***@gmail.com>
> > > >> wrote:
> > > >>
> > > >>> This guy has what looks like a well thought out design using a
> > > Sirf-Based
> > > >>> GPS and ATTiny44A chip to generate a signal to update his watch:
> > > >>>
> > > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> > > >>>
> > > >>> Unfortunately, he doesn't seem to have published a schematic or his
> > > >> source
> > > >>> code. But, he covers enough detail that I think it wouldn't be too
> > > hard
> > > >> to
> > > >>> replicate what he's done. Or, perhaps he would disclose these
> > details
> > > if
> > > >>> contacted.
> > > >>>
> > > >>> Wayne
> > > >>>
> > > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
> > > >> wrote:
> > > >>>
> > > >>>> I thought I would search in a different way for a WWVB signal
> > > generator
> > > >>>> design. I found this item. While the designer explains it isn't
> as
> > > >>>> accurate as WWVB it may be another starting point.
> > > >>>>
> > > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> > > signal-generator.htm
> > > >>>>
> > > >>>>
> > > >>>>
> > > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > > >>>> http://hammondorganservice.com
> > > >>>> Hammond USA warranty service
> > > >>>> "Most people don't have a sense of humor. They think they do, but
> > they
> > > >>>> don't." --Jonathan Winters
> > > >>>>
> > > >>>> _______________________________________________
> > > >>>> time-nuts mailing list -- time-***@lists.febo.com
> > > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> > > >>>> listinfo/time-nuts_lists.febo.com
> > > >>>> and follow the instructions there.
> > > >>>>
> > > >>> _______________________________________________
> > > >>> time-nuts mailing list -- time-***@lists.febo.com
> > > >>> To unsubscribe, go to
> > > >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > >>> and follow the instructions there.
> > > >>>
> > > >> _______________________________________________
> > > >> time-nuts mailing list -- time-***@lists.febo.com
> > > >> To unsubscribe, go to http://lists.febo.com/mailman/
> > > >> listinfo/time-nuts_lists.febo.com
> > > >> and follow the instructions there.
> > > >>
> > > > _______________________________________________
> > > > time-nuts mailing list -- time-***@lists.febo.com
> > > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > > and follow the instructions there.
> > >
> > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
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and fol
Wayne Holder
2018-08-30 01:03:15 UTC
Permalink
For those that have asked for my to publish the source code for my
ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly written
page on my google site at:

https://sites.google.com/site/wayneholder/controlling-time

that describes a bit about how the code works, how to compile it using the
Arduino IDE, how I tested it, some issues I have observed in testing it
and, at the bottom of the page, a downloadable zip file that contains the
complete source code.

Note: as mentioned at the top of this page, this is currently a work in
process, so I'm not yet going to link the article to my main website page,
so you'll need to link in this post to find it. Also, as draft, I'm going
to continue to revise the page until I feel the project is complete enough
to publish. That means the source code zip file is going to potentially
change from time to time, too.

Wayne

On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <***@gmail.com> wrote:

> As a follow up, I now have a simple WWVB simulator written in C that's now
> running an an ATTiny85 using nothing more than the internal, 8
> mHz oscillator and about a 6 inch length of wire connected to one of the
> pins as an antenna. It generates an approximate 60 kHz signal using PWM on
> timer 1. I tweaked the timer value a bit to correct for some variance in
> the internal oscillator, but I' not even sure that was necessary, as my
> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
> Modulation is done by varying the duty cycle of the PWM to approximate the
> -17 dBr drop on the carrier. But, again, I don't think this value is
> critical with a consumer clock chip. I tapped the demodulated output
> inside the clock and displayed it on my scope along with the generated
> signal and I got good, steady demodulation with the wire antenna just
> placed near clock. The next step is to connect up a GPS module and add
> code to use it to set the time. I'm also going to change the code to use
> the PPS signal from the GPS to drive the output timing rather than the test
> code I have now that uses timer 0 to generate the PPS interrupt. I'm happy
> to share details if anyone is interested.
>
> Wayne
>
>
>
> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com> wrote:
>
>> That would be a great neighbor to have but I can tell you around here its
>> the phone. Not to concerned about someone putting up a wwvb replacement.
>> And I can always up the power. Chickle.
>> Regards
>> Paul
>>
>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
>>
>> > Hi
>> >
>> > The gotcha is if you have neighbors two or three doors away that *also*
>> > put up one of
>> > these devices. You then have a real problem with the neighbor(s) in the
>> > middle. The
>> > wavelength is long enough that Raleigh issues won’t get you. You still
>> > have the two
>> > signals ( at slightly different frequencies) beating against each other.
>> > The result is
>> > going to show up as who knows what to this or that receiver. With a
>> > precision receiver,
>> > you might even have issues from the guy two houses away …...
>> >
>> > Bob
>> >
>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
>> > >
>> > > Agree with the conversation. With respect to neighbors when the day
>> comes
>> > > they may ask you to boost your signal. :-)
>> > > Granted maybe the day won't come but at least having your local clocks
>> > work
>> > > is nice.
>> > > Regards
>> > > Paul
>> > > WB8TSL
>> > >
>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <***@gmail.com
>> >
>> > > wrote:
>> > >
>> > >> With the watch being physically close to the faux WWVB "transmitter",
>> > one
>> > >> is in
>> > >> the so-called "near field" regime, where the field strength (V/m)
>> falls
>> > as
>> > >> the inverse
>> > >> cube of the distance. If one is putting the watch, say, within a few
>> > >> inches of the
>> > >> transmitter, reliable reception should be available yet the signal
>> > should
>> > >> be literally
>> > >> undetectable by any practical receiving device more than a few feet
>> > away.
>> > >> Hence,
>> > >> meeting the FCC field strength limit should be trivial.if the device
>> is
>> > >> used as pictured.
>> > >> However, if one cranks up the power enough to reliably cover one's
>> > entire
>> > >> house,
>> > >> then there might be a problem depending how close the nearest
>> neighbor
>> > >> lives,
>> > >> even at levels well within the FCC limit he quotes.
>> > >>
>> > >> Taking the near field relationship in hand, 40 uV/m at 300m would
>> > translate
>> > >> into
>> > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed
>> most
>> > >> peoples'
>> > >> entire house. So the pragmatic issue would again be- neighbors. On
>> the
>> > >> other
>> > >> hand, most of them would never be aware of the local signal as long
>> as
>> > they
>> > >> get good
>> > >> time settings, unless they live close enough to Ft. Collins for the
>> two
>> > >> signals to
>> > >> contend with each other.
>> > >>
>> > >> It looks to me like the ferrite rod antenna is considerable overkill.
>> > Even
>> > >> with no
>> > >> purposeful antenna I'd expect leakage to yield sufficient signal for
>> at
>> > >> least a few
>> > >> inches.
>> > >>
>> > >> Dana
>> > >>
>> > >>
>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <***@gmail.com
>> >
>> > >> wrote:
>> > >>
>> > >>> This guy has what looks like a well thought out design using a
>> > Sirf-Based
>> > >>> GPS and ATTiny44A chip to generate a signal to update his watch:
>> > >>>
>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
>> > >>>
>> > >>> Unfortunately, he doesn't seem to have published a schematic or his
>> > >> source
>> > >>> code. But, he covers enough detail that I think it wouldn't be too
>> > hard
>> > >> to
>> > >>> replicate what he's done. Or, perhaps he would disclose these
>> details
>> > if
>> > >>> contacted.
>> > >>>
>> > >>> Wayne
>> > >>>
>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
>> > >> wrote:
>> > >>>
>> > >>>> I thought I would search in a different way for a WWVB signal
>> > generator
>> > >>>> design. I found this item. While the designer explains it isn't
>> as
>> > >>>> accurate as WWVB it may be another starting point.
>> > >>>>
>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
>> > signal-generator.htm
>> > >>>>
>> > >>>>
>> > >>>>
>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
>> > >>>> http://hammondorganservice.com
>> > >>>> Hammond USA warranty service
>> > >>>> "Most people don't have a sense of humor. They think they do, but
>> they
>> > >>>> don't." --Jonathan Winters
>> > >>>>
>> > >>>> _______________________________________________
>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
>> > >>>> listinfo/time-nuts_lists.febo.com
>> > >>>> and follow the instructions there.
>> > >>>>
>> > >>> _______________________________________________
>> > >>> time-nuts mailing list -- time-***@lists.febo.com
>> > >>> To unsubscribe, go to
>> > >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> > >>> and follow the instructions there.
>> > >>>
>> > >> _______________________________________________
>> > >> time-nuts mailing list -- time-***@lists.febo.com
>> > >> To unsubscribe, go to http://lists.febo.com/mailman/
>> > >> listinfo/time-nuts_lists.febo.com
>> > >> and follow the instructions there.
>> > >>
>> > > _______________________________________________
>> > > time-nuts mailing list -- time-***@lists.febo.com
>> > > To unsubscribe, go to http://lists.febo.com/mailman/
>> > listinfo/time-nuts_lists.febo.com
>> > > and follow the instructions there.
>> >
>> >
>> > _______________________________________________
>> > time-nuts mailing list -- time-***@lists.febo.com
>> > To unsubscribe, go to http://lists.febo.com/mailman/
>> > listinfo/time-nuts_lists.febo.com
>> > and follow the instructions there.
>> >
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>
>
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Wayne Holder
2018-08-30 09:12:27 UTC
Permalink
For anyone trying out my ATTiny85 code, I've done some additional tests and
find that placement of the antenna near the clock is very finicky and, so
far, the only way to get a reliable decode of the time in the clock is by
using a scope to monitor the demodulated output and then moving the antenna
around until the demodulated signal lines up cleanly with modulated carrier
and there are no intra bit glitches. This can take a bit of patience, so
clearly a better solution needs to be found. I've found that any type of
glitch in the demodulated signal seems to prevent the clock chip from
decoding the time.

It's possible the difficultly with locking onto my simulated WWVB signal
may be partially due to the design of the clock (from my location it's
never been able to to lock onto the real WWVB signal), but I have no
reference to compare it against so, for now, I have conclude that the
PWM-based modulation scheme my code uses may also be suboptimal for this
application. To make testing even more frustrating, the BALDR clock I'm
using will only look for a signal for about 6 minutes before it goes to
sleep and I have to then power cycle the clock to get it to listen again.

So, keep this in mind if you're going to try and replicate my results.

Wayne

On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <***@gmail.com> wrote:

> For those that have asked for my to publish the source code for my
> ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly written
> page on my google site at:
>
> https://sites.google.com/site/wayneholder/controlling-time
>
> that describes a bit about how the code works, how to compile it using the
> Arduino IDE, how I tested it, some issues I have observed in testing it
> and, at the bottom of the page, a downloadable zip file that contains the
> complete source code.
>
> Note: as mentioned at the top of this page, this is currently a work in
> process, so I'm not yet going to link the article to my main website page,
> so you'll need to link in this post to find it. Also, as draft, I'm going
> to continue to revise the page until I feel the project is complete enough
> to publish. That means the source code zip file is going to potentially
> change from time to time, too.
>
> Wayne
>
> On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <***@gmail.com>
> wrote:
>
>> As a follow up, I now have a simple WWVB simulator written in C that's
>> now running an an ATTiny85 using nothing more than the internal, 8
>> mHz oscillator and about a 6 inch length of wire connected to one of the
>> pins as an antenna. It generates an approximate 60 kHz signal using PWM on
>> timer 1. I tweaked the timer value a bit to correct for some variance in
>> the internal oscillator, but I' not even sure that was necessary, as my
>> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
>> Modulation is done by varying the duty cycle of the PWM to approximate the
>> -17 dBr drop on the carrier. But, again, I don't think this value is
>> critical with a consumer clock chip. I tapped the demodulated output
>> inside the clock and displayed it on my scope along with the generated
>> signal and I got good, steady demodulation with the wire antenna just
>> placed near clock. The next step is to connect up a GPS module and add
>> code to use it to set the time. I'm also going to change the code to use
>> the PPS signal from the GPS to drive the output timing rather than the test
>> code I have now that uses timer 0 to generate the PPS interrupt. I'm happy
>> to share details if anyone is interested.
>>
>> Wayne
>>
>>
>>
>> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com> wrote:
>>
>>> That would be a great neighbor to have but I can tell you around here its
>>> the phone. Not to concerned about someone putting up a wwvb replacement.
>>> And I can always up the power. Chickle.
>>> Regards
>>> Paul
>>>
>>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
>>>
>>> > Hi
>>> >
>>> > The gotcha is if you have neighbors two or three doors away that *also*
>>> > put up one of
>>> > these devices. You then have a real problem with the neighbor(s) in the
>>> > middle. The
>>> > wavelength is long enough that Raleigh issues won’t get you. You still
>>> > have the two
>>> > signals ( at slightly different frequencies) beating against each
>>> other.
>>> > The result is
>>> > going to show up as who knows what to this or that receiver. With a
>>> > precision receiver,
>>> > you might even have issues from the guy two houses away …...
>>> >
>>> > Bob
>>> >
>>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com> wrote:
>>> > >
>>> > > Agree with the conversation. With respect to neighbors when the day
>>> comes
>>> > > they may ask you to boost your signal. :-)
>>> > > Granted maybe the day won't come but at least having your local
>>> clocks
>>> > work
>>> > > is nice.
>>> > > Regards
>>> > > Paul
>>> > > WB8TSL
>>> > >
>>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
>>> ***@gmail.com>
>>> > > wrote:
>>> > >
>>> > >> With the watch being physically close to the faux WWVB
>>> "transmitter",
>>> > one
>>> > >> is in
>>> > >> the so-called "near field" regime, where the field strength (V/m)
>>> falls
>>> > as
>>> > >> the inverse
>>> > >> cube of the distance. If one is putting the watch, say, within a
>>> few
>>> > >> inches of the
>>> > >> transmitter, reliable reception should be available yet the signal
>>> > should
>>> > >> be literally
>>> > >> undetectable by any practical receiving device more than a few feet
>>> > away.
>>> > >> Hence,
>>> > >> meeting the FCC field strength limit should be trivial.if the
>>> device is
>>> > >> used as pictured.
>>> > >> However, if one cranks up the power enough to reliably cover one's
>>> > entire
>>> > >> house,
>>> > >> then there might be a problem depending how close the nearest
>>> neighbor
>>> > >> lives,
>>> > >> even at levels well within the FCC limit he quotes.
>>> > >>
>>> > >> Taking the near field relationship in hand, 40 uV/m at 300m would
>>> > translate
>>> > >> into
>>> > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed
>>> most
>>> > >> peoples'
>>> > >> entire house. So the pragmatic issue would again be- neighbors.
>>> On the
>>> > >> other
>>> > >> hand, most of them would never be aware of the local signal as long
>>> as
>>> > they
>>> > >> get good
>>> > >> time settings, unless they live close enough to Ft. Collins for the
>>> two
>>> > >> signals to
>>> > >> contend with each other.
>>> > >>
>>> > >> It looks to me like the ferrite rod antenna is considerable
>>> overkill.
>>> > Even
>>> > >> with no
>>> > >> purposeful antenna I'd expect leakage to yield sufficient signal
>>> for at
>>> > >> least a few
>>> > >> inches.
>>> > >>
>>> > >> Dana
>>> > >>
>>> > >>
>>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
>>> ***@gmail.com>
>>> > >> wrote:
>>> > >>
>>> > >>> This guy has what looks like a well thought out design using a
>>> > Sirf-Based
>>> > >>> GPS and ATTiny44A chip to generate a signal to update his watch:
>>> > >>>
>>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
>>> > >>>
>>> > >>> Unfortunately, he doesn't seem to have published a schematic or his
>>> > >> source
>>> > >>> code. But, he covers enough detail that I think it wouldn't be too
>>> > hard
>>> > >> to
>>> > >>> replicate what he's done. Or, perhaps he would disclose these
>>> details
>>> > if
>>> > >>> contacted.
>>> > >>>
>>> > >>> Wayne
>>> > >>>
>>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <***@pacbell.net>
>>> > >> wrote:
>>> > >>>
>>> > >>>> I thought I would search in a different way for a WWVB signal
>>> > generator
>>> > >>>> design. I found this item. While the designer explains it isn't
>>> as
>>> > >>>> accurate as WWVB it may be another starting point.
>>> > >>>>
>>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
>>> > signal-generator.htm
>>> > >>>>
>>> > >>>>
>>> > >>>>
>>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
>>> > >>>> http://hammondorganservice.com
>>> > >>>> Hammond USA warranty service
>>> > >>>> "Most people don't have a sense of humor. They think they do, but
>>> they
>>> > >>>> don't." --Jonathan Winters
>>> > >>>>
>>> > >>>> _______________________________________________
>>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
>>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>> > >>>> listinfo/time-nuts_lists.febo.com
>>> > >>>> and follow the instructions there.
>>> > >>>>
>>> > >>> _______________________________________________
>>> > >>> time-nuts mailing list -- time-***@lists.febo.com
>>> > >>> To unsubscribe, go to
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>>> > >>> and follow the instructions there.
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>>> > > To unsubscribe, go to http://lists.febo.com/mailman/
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paul swed
2018-08-30 15:52:18 UTC
Permalink
Wayne as I work through the chronverter I do know the good phase tracking
clocks really demand on frequency behavior. As I measured its +/- .6 Hz at
60 KHz. I believe the cheapy wall clocks are a bit wider, but not sure as
they are hard to actually measure. They do use a small tuning fork crystal
and from experience these are sharp. When I experimented with them they
were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals for
maybe $2.
With respect to the antenna. My thinking is a loopstick resonated on 60 KHz
and most likely driving it push pull or single ended. Thats 1 transistor if
single ended as common collector if I had to guess. The reason is the
micros put out a fair level of signal so its a case of upping current into
the antenna. But it really will be a bit of experimenting.
I did look at your code and that was so nice it opened up straight into the
arduino IDE.
Regards
Paul
WB8TSL

On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <***@gmail.com>
wrote:

> For anyone trying out my ATTiny85 code, I've done some additional tests and
> find that placement of the antenna near the clock is very finicky and, so
> far, the only way to get a reliable decode of the time in the clock is by
> using a scope to monitor the demodulated output and then moving the antenna
> around until the demodulated signal lines up cleanly with modulated carrier
> and there are no intra bit glitches. This can take a bit of patience, so
> clearly a better solution needs to be found. I've found that any type of
> glitch in the demodulated signal seems to prevent the clock chip from
> decoding the time.
>
> It's possible the difficultly with locking onto my simulated WWVB signal
> may be partially due to the design of the clock (from my location it's
> never been able to to lock onto the real WWVB signal), but I have no
> reference to compare it against so, for now, I have conclude that the
> PWM-based modulation scheme my code uses may also be suboptimal for this
> application. To make testing even more frustrating, the BALDR clock I'm
> using will only look for a signal for about 6 minutes before it goes to
> sleep and I have to then power cycle the clock to get it to listen again.
>
> So, keep this in mind if you're going to try and replicate my results.
>
> Wayne
>
> On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <***@gmail.com>
> wrote:
>
> > For those that have asked for my to publish the source code for my
> > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly written
> > page on my google site at:
> >
> > https://sites.google.com/site/wayneholder/controlling-time
> >
> > that describes a bit about how the code works, how to compile it using
> the
> > Arduino IDE, how I tested it, some issues I have observed in testing it
> > and, at the bottom of the page, a downloadable zip file that contains the
> > complete source code.
> >
> > Note: as mentioned at the top of this page, this is currently a work in
> > process, so I'm not yet going to link the article to my main website
> page,
> > so you'll need to link in this post to find it. Also, as draft, I'm
> going
> > to continue to revise the page until I feel the project is complete
> enough
> > to publish. That means the source code zip file is going to potentially
> > change from time to time, too.
> >
> > Wayne
> >
> > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <***@gmail.com>
> > wrote:
> >
> >> As a follow up, I now have a simple WWVB simulator written in C that's
> >> now running an an ATTiny85 using nothing more than the internal, 8
> >> mHz oscillator and about a 6 inch length of wire connected to one of the
> >> pins as an antenna. It generates an approximate 60 kHz signal using
> PWM on
> >> timer 1. I tweaked the timer value a bit to correct for some variance
> in
> >> the internal oscillator, but I' not even sure that was necessary, as my
> >> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
> >> Modulation is done by varying the duty cycle of the PWM to approximate
> the
> >> -17 dBr drop on the carrier. But, again, I don't think this value is
> >> critical with a consumer clock chip. I tapped the demodulated output
> >> inside the clock and displayed it on my scope along with the generated
> >> signal and I got good, steady demodulation with the wire antenna just
> >> placed near clock. The next step is to connect up a GPS module and add
> >> code to use it to set the time. I'm also going to change the code to
> use
> >> the PPS signal from the GPS to drive the output timing rather than the
> test
> >> code I have now that uses timer 0 to generate the PPS interrupt. I'm
> happy
> >> to share details if anyone is interested.
> >>
> >> Wayne
> >>
> >>
> >>
> >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com> wrote:
> >>
> >>> That would be a great neighbor to have but I can tell you around here
> its
> >>> the phone. Not to concerned about someone putting up a wwvb
> replacement.
> >>> And I can always up the power. Chickle.
> >>> Regards
> >>> Paul
> >>>
> >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
> >>>
> >>> > Hi
> >>> >
> >>> > The gotcha is if you have neighbors two or three doors away that
> *also*
> >>> > put up one of
> >>> > these devices. You then have a real problem with the neighbor(s) in
> the
> >>> > middle. The
> >>> > wavelength is long enough that Raleigh issues won’t get you. You
> still
> >>> > have the two
> >>> > signals ( at slightly different frequencies) beating against each
> >>> other.
> >>> > The result is
> >>> > going to show up as who knows what to this or that receiver. With a
> >>> > precision receiver,
> >>> > you might even have issues from the guy two houses away …...
> >>> >
> >>> > Bob
> >>> >
> >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com>
> wrote:
> >>> > >
> >>> > > Agree with the conversation. With respect to neighbors when the day
> >>> comes
> >>> > > they may ask you to boost your signal. :-)
> >>> > > Granted maybe the day won't come but at least having your local
> >>> clocks
> >>> > work
> >>> > > is nice.
> >>> > > Regards
> >>> > > Paul
> >>> > > WB8TSL
> >>> > >
> >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> >>> ***@gmail.com>
> >>> > > wrote:
> >>> > >
> >>> > >> With the watch being physically close to the faux WWVB
> >>> "transmitter",
> >>> > one
> >>> > >> is in
> >>> > >> the so-called "near field" regime, where the field strength (V/m)
> >>> falls
> >>> > as
> >>> > >> the inverse
> >>> > >> cube of the distance. If one is putting the watch, say, within a
> >>> few
> >>> > >> inches of the
> >>> > >> transmitter, reliable reception should be available yet the signal
> >>> > should
> >>> > >> be literally
> >>> > >> undetectable by any practical receiving device more than a few
> feet
> >>> > away.
> >>> > >> Hence,
> >>> > >> meeting the FCC field strength limit should be trivial.if the
> >>> device is
> >>> > >> used as pictured.
> >>> > >> However, if one cranks up the power enough to reliably cover one's
> >>> > entire
> >>> > >> house,
> >>> > >> then there might be a problem depending how close the nearest
> >>> neighbor
> >>> > >> lives,
> >>> > >> even at levels well within the FCC limit he quotes.
> >>> > >>
> >>> > >> Taking the near field relationship in hand, 40 uV/m at 300m would
> >>> > translate
> >>> > >> into
> >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed
> >>> most
> >>> > >> peoples'
> >>> > >> entire house. So the pragmatic issue would again be- neighbors.
> >>> On the
> >>> > >> other
> >>> > >> hand, most of them would never be aware of the local signal as
> long
> >>> as
> >>> > they
> >>> > >> get good
> >>> > >> time settings, unless they live close enough to Ft. Collins for
> the
> >>> two
> >>> > >> signals to
> >>> > >> contend with each other.
> >>> > >>
> >>> > >> It looks to me like the ferrite rod antenna is considerable
> >>> overkill.
> >>> > Even
> >>> > >> with no
> >>> > >> purposeful antenna I'd expect leakage to yield sufficient signal
> >>> for at
> >>> > >> least a few
> >>> > >> inches.
> >>> > >>
> >>> > >> Dana
> >>> > >>
> >>> > >>
> >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> >>> ***@gmail.com>
> >>> > >> wrote:
> >>> > >>
> >>> > >>> This guy has what looks like a well thought out design using a
> >>> > Sirf-Based
> >>> > >>> GPS and ATTiny44A chip to generate a signal to update his watch:
> >>> > >>>
> >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> >>> > >>>
> >>> > >>> Unfortunately, he doesn't seem to have published a schematic or
> his
> >>> > >> source
> >>> > >>> code. But, he covers enough detail that I think it wouldn't be
> too
> >>> > hard
> >>> > >> to
> >>> > >>> replicate what he's done. Or, perhaps he would disclose these
> >>> details
> >>> > if
> >>> > >>> contacted.
> >>> > >>>
> >>> > >>> Wayne
> >>> > >>>
> >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
> ***@pacbell.net>
> >>> > >> wrote:
> >>> > >>>
> >>> > >>>> I thought I would search in a different way for a WWVB signal
> >>> > generator
> >>> > >>>> design. I found this item. While the designer explains it
> isn't
> >>> as
> >>> > >>>> accurate as WWVB it may be another starting point.
> >>> > >>>>
> >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> >>> > signal-generator.htm
> >>> > >>>>
> >>> > >>>>
> >>> > >>>>
> >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> >>> > >>>> http://hammondorganservice.com
> >>> > >>>> Hammond USA warranty service
> >>> > >>>> "Most people don't have a sense of humor. They think they do,
> but
> >>> they
> >>> > >>>> don't." --Jonathan Winters
> >>> > >>>>
> >>> > >>>> _______________________________________________
> >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
> >>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> >>> > >>>> listinfo/time-nuts_lists.febo.com
> >>> > >>>> and follow the instructions there.
> >>> > >>>>
> >>> > >>> _______________________________________________
> >>> > >>> time-nuts mailing list -- time-***@lists.febo.com
> >>> > >>> To unsubscribe, go to
> >>> > >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> >>> > >>> and follow the instructions there.
> >>> > >>>
> >>> > >> _______________________________________________
> >>> > >> time-nuts mailing list -- time-***@lists.febo.com
> >>> > >> To unsubscribe, go to http://lists.febo.com/mailman/
> >>> > >> listinfo/time-nuts_lists.febo.com
> >>> > >> and follow the instructions there.
> >>> > >>
> >>> > > _______________________________________________
> >>> > > time-nuts mailing list -- time-***@lists.febo.com
> >>> > > To unsubscribe, go to http://lists.febo.com/mailman/
> >>> > listinfo/time-nuts_lists.febo.com
> >>> > > and follow the instructions there.
> >>> >
> >>> >
> >>> > _______________________________________________
> >>> > time-nuts mailing list -- time-***@lists.febo.com
> >>> > To unsubscribe, go to http://lists.febo.com/mailman/
> >>> > listinfo/time-nuts_lists.febo.com
> >>> > and follow the instructions there.
> >>> >
> >>> _______________________________________________
> >>> time-nuts mailing list -- time-***@lists.febo.com
> >>> To unsubscribe, go to
> >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> >>> and follow the instructions there.
> >>>
> >>
> >>
> _______________________________________________
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> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
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and follow the
Wayne Holder
2018-08-31 01:44:30 UTC
Permalink
I've had some luck improving things with my ATTiny85-based WWVB Simulator
design by replacing the crappy, 8 MHz internal oscillator with an 8 MHz
crystal and removing the tweaked timer values I had previously used. In
addition, based on a suggestion from Paul Swed, I tried looping the antenna
wire a few times around the ferrite rod of a WWVB receiver module I
happened to have lying around and this also greatly improved things (see
photo on web page at
https://sites.google.com/site/wayneholder/controlling-time). In fact, with
the ferrite rod in place, the BALDR clock now syncs even when completely
disconnected from being grounded to the ATTiny85 and the scope.

I've updated my web page, and the source code at the bottom of the page,
accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS output
is currently disabled in the code. In addition, I've added some additional
info on my web page about how to compile and download the program to an
ATTiny85 using ATTinyCore by Spence Konde.

I've ordered a 15.36 MHz crystal to try, as that should let the ATTiny85
generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has helped
improve things quite a bit. In addition, I plan to do more tests on
different types of antennas in order to see if I can make things even more
reliable and stable.

I still plan on reworking the code so it can also run on a 328-based
Arduino board but, currently, the Arduino IDE has no easy way to work with
boards that don't use a standard, 16 MHz crystal, as this frequency is used
by the serial port and, in turn, by the boot loader, so altering it can
break the ability to upload code. This has actually caused some issues for
some of my other projects, so I'm investigating how this issue might be
handled.

Also, if anyone is interested in trying out other modulation schemes, I can
easily add a compile option t the code that will let it output a binary
low/high modulation signal instead of the PWM signal.

Wayne

On Thu, Aug 30, 2018 at 8:53 AM paul swed <***@gmail.com> wrote:

> Wayne as I work through the chronverter I do know the good phase tracking
> clocks really demand on frequency behavior. As I measured its +/- .6 Hz at
> 60 KHz. I believe the cheapy wall clocks are a bit wider, but not sure as
> they are hard to actually measure. They do use a small tuning fork crystal
> and from experience these are sharp. When I experimented with them they
> were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals for
> maybe $2.
> With respect to the antenna. My thinking is a loopstick resonated on 60 KHz
> and most likely driving it push pull or single ended. Thats 1 transistor if
> single ended as common collector if I had to guess. The reason is the
> micros put out a fair level of signal so its a case of upping current into
> the antenna. But it really will be a bit of experimenting.
> I did look at your code and that was so nice it opened up straight into the
> arduino IDE.
> Regards
> Paul
> WB8TSL
>
> On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <***@gmail.com>
> wrote:
>
> > For anyone trying out my ATTiny85 code, I've done some additional tests
> and
> > find that placement of the antenna near the clock is very finicky and, so
> > far, the only way to get a reliable decode of the time in the clock is by
> > using a scope to monitor the demodulated output and then moving the
> antenna
> > around until the demodulated signal lines up cleanly with modulated
> carrier
> > and there are no intra bit glitches. This can take a bit of patience, so
> > clearly a better solution needs to be found. I've found that any type of
> > glitch in the demodulated signal seems to prevent the clock chip from
> > decoding the time.
> >
> > It's possible the difficultly with locking onto my simulated WWVB signal
> > may be partially due to the design of the clock (from my location it's
> > never been able to to lock onto the real WWVB signal), but I have no
> > reference to compare it against so, for now, I have conclude that the
> > PWM-based modulation scheme my code uses may also be suboptimal for this
> > application. To make testing even more frustrating, the BALDR clock I'm
> > using will only look for a signal for about 6 minutes before it goes to
> > sleep and I have to then power cycle the clock to get it to listen again.
> >
> > So, keep this in mind if you're going to try and replicate my results.
> >
> > Wayne
> >
> > On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <***@gmail.com>
> > wrote:
> >
> > > For those that have asked for my to publish the source code for my
> > > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly
> written
> > > page on my google site at:
> > >
> > > https://sites.google.com/site/wayneholder/controlling-time
> > >
> > > that describes a bit about how the code works, how to compile it using
> > the
> > > Arduino IDE, how I tested it, some issues I have observed in testing it
> > > and, at the bottom of the page, a downloadable zip file that contains
> the
> > > complete source code.
> > >
> > > Note: as mentioned at the top of this page, this is currently a work in
> > > process, so I'm not yet going to link the article to my main website
> > page,
> > > so you'll need to link in this post to find it. Also, as draft, I'm
> > going
> > > to continue to revise the page until I feel the project is complete
> > enough
> > > to publish. That means the source code zip file is going to
> potentially
> > > change from time to time, too.
> > >
> > > Wayne
> > >
> > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <***@gmail.com>
> > > wrote:
> > >
> > >> As a follow up, I now have a simple WWVB simulator written in C that's
> > >> now running an an ATTiny85 using nothing more than the internal, 8
> > >> mHz oscillator and about a 6 inch length of wire connected to one of
> the
> > >> pins as an antenna. It generates an approximate 60 kHz signal using
> > PWM on
> > >> timer 1. I tweaked the timer value a bit to correct for some variance
> > in
> > >> the internal oscillator, but I' not even sure that was necessary, as
> my
> > >> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock.
> > >> Modulation is done by varying the duty cycle of the PWM to approximate
> > the
> > >> -17 dBr drop on the carrier. But, again, I don't think this value is
> > >> critical with a consumer clock chip. I tapped the demodulated output
> > >> inside the clock and displayed it on my scope along with the generated
> > >> signal and I got good, steady demodulation with the wire antenna just
> > >> placed near clock. The next step is to connect up a GPS module and
> add
> > >> code to use it to set the time. I'm also going to change the code to
> > use
> > >> the PPS signal from the GPS to drive the output timing rather than the
> > test
> > >> code I have now that uses timer 0 to generate the PPS interrupt. I'm
> > happy
> > >> to share details if anyone is interested.
> > >>
> > >> Wayne
> > >>
> > >>
> > >>
> > >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com>
> wrote:
> > >>
> > >>> That would be a great neighbor to have but I can tell you around here
> > its
> > >>> the phone. Not to concerned about someone putting up a wwvb
> > replacement.
> > >>> And I can always up the power. Chickle.
> > >>> Regards
> > >>> Paul
> > >>>
> > >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
> > >>>
> > >>> > Hi
> > >>> >
> > >>> > The gotcha is if you have neighbors two or three doors away that
> > *also*
> > >>> > put up one of
> > >>> > these devices. You then have a real problem with the neighbor(s) in
> > the
> > >>> > middle. The
> > >>> > wavelength is long enough that Raleigh issues won’t get you. You
> > still
> > >>> > have the two
> > >>> > signals ( at slightly different frequencies) beating against each
> > >>> other.
> > >>> > The result is
> > >>> > going to show up as who knows what to this or that receiver. With a
> > >>> > precision receiver,
> > >>> > you might even have issues from the guy two houses away …...
> > >>> >
> > >>> > Bob
> > >>> >
> > >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com>
> > wrote:
> > >>> > >
> > >>> > > Agree with the conversation. With respect to neighbors when the
> day
> > >>> comes
> > >>> > > they may ask you to boost your signal. :-)
> > >>> > > Granted maybe the day won't come but at least having your local
> > >>> clocks
> > >>> > work
> > >>> > > is nice.
> > >>> > > Regards
> > >>> > > Paul
> > >>> > > WB8TSL
> > >>> > >
> > >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> > >>> ***@gmail.com>
> > >>> > > wrote:
> > >>> > >
> > >>> > >> With the watch being physically close to the faux WWVB
> > >>> "transmitter",
> > >>> > one
> > >>> > >> is in
> > >>> > >> the so-called "near field" regime, where the field strength
> (V/m)
> > >>> falls
> > >>> > as
> > >>> > >> the inverse
> > >>> > >> cube of the distance. If one is putting the watch, say, within
> a
> > >>> few
> > >>> > >> inches of the
> > >>> > >> transmitter, reliable reception should be available yet the
> signal
> > >>> > should
> > >>> > >> be literally
> > >>> > >> undetectable by any practical receiving device more than a few
> > feet
> > >>> > away.
> > >>> > >> Hence,
> > >>> > >> meeting the FCC field strength limit should be trivial.if the
> > >>> device is
> > >>> > >> used as pictured.
> > >>> > >> However, if one cranks up the power enough to reliably cover
> one's
> > >>> > entire
> > >>> > >> house,
> > >>> > >> then there might be a problem depending how close the nearest
> > >>> neighbor
> > >>> > >> lives,
> > >>> > >> even at levels well within the FCC limit he quotes.
> > >>> > >>
> > >>> > >> Taking the near field relationship in hand, 40 uV/m at 300m
> would
> > >>> > translate
> > >>> > >> into
> > >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough to
> feed
> > >>> most
> > >>> > >> peoples'
> > >>> > >> entire house. So the pragmatic issue would again be- neighbors.
> > >>> On the
> > >>> > >> other
> > >>> > >> hand, most of them would never be aware of the local signal as
> > long
> > >>> as
> > >>> > they
> > >>> > >> get good
> > >>> > >> time settings, unless they live close enough to Ft. Collins for
> > the
> > >>> two
> > >>> > >> signals to
> > >>> > >> contend with each other.
> > >>> > >>
> > >>> > >> It looks to me like the ferrite rod antenna is considerable
> > >>> overkill.
> > >>> > Even
> > >>> > >> with no
> > >>> > >> purposeful antenna I'd expect leakage to yield sufficient signal
> > >>> for at
> > >>> > >> least a few
> > >>> > >> inches.
> > >>> > >>
> > >>> > >> Dana
> > >>> > >>
> > >>> > >>
> > >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> > >>> ***@gmail.com>
> > >>> > >> wrote:
> > >>> > >>
> > >>> > >>> This guy has what looks like a well thought out design using a
> > >>> > Sirf-Based
> > >>> > >>> GPS and ATTiny44A chip to generate a signal to update his
> watch:
> > >>> > >>>
> > >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> > >>> > >>>
> > >>> > >>> Unfortunately, he doesn't seem to have published a schematic or
> > his
> > >>> > >> source
> > >>> > >>> code. But, he covers enough detail that I think it wouldn't be
> > too
> > >>> > hard
> > >>> > >> to
> > >>> > >>> replicate what he's done. Or, perhaps he would disclose these
> > >>> details
> > >>> > if
> > >>> > >>> contacted.
> > >>> > >>>
> > >>> > >>> Wayne
> > >>> > >>>
> > >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
> > ***@pacbell.net>
> > >>> > >> wrote:
> > >>> > >>>
> > >>> > >>>> I thought I would search in a different way for a WWVB signal
> > >>> > generator
> > >>> > >>>> design. I found this item. While the designer explains it
> > isn't
> > >>> as
> > >>> > >>>> accurate as WWVB it may be another starting point.
> > >>> > >>>>
> > >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> > >>> > signal-generator.htm
> > >>> > >>>>
> > >>> > >>>>
> > >>> > >>>>
> > >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > >>> > >>>> http://hammondorganservice.com
> > >>> > >>>> Hammond USA warranty service
> > >>> > >>>> "Most people don't have a sense of humor. They think they do,
> > but
> > >>> they
> > >>> > >>>> don't." --Jonathan Winters
> > >>> > >>>>
> > >>> > >>>> _______________________________________________
> > >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
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paul swed
2018-08-31 03:03:16 UTC
Permalink
Wayne very good progress. You can actually feed the loop coild that exists
with the cap it should resonate.
Thats my plan at least.
Regards
Paul
WB8TSL

On Thu, Aug 30, 2018 at 9:44 PM, Wayne Holder <***@gmail.com>
wrote:

> I've had some luck improving things with my ATTiny85-based WWVB Simulator
> design by replacing the crappy, 8 MHz internal oscillator with an 8 MHz
> crystal and removing the tweaked timer values I had previously used. In
> addition, based on a suggestion from Paul Swed, I tried looping the antenna
> wire a few times around the ferrite rod of a WWVB receiver module I
> happened to have lying around and this also greatly improved things (see
> photo on web page at
> https://sites.google.com/site/wayneholder/controlling-time). In fact,
> with
> the ferrite rod in place, the BALDR clock now syncs even when completely
> disconnected from being grounded to the ATTiny85 and the scope.
>
> I've updated my web page, and the source code at the bottom of the page,
> accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS output
> is currently disabled in the code. In addition, I've added some additional
> info on my web page about how to compile and download the program to an
> ATTiny85 using ATTinyCore by Spence Konde.
>
> I've ordered a 15.36 MHz crystal to try, as that should let the ATTiny85
> generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has helped
> improve things quite a bit. In addition, I plan to do more tests on
> different types of antennas in order to see if I can make things even more
> reliable and stable.
>
> I still plan on reworking the code so it can also run on a 328-based
> Arduino board but, currently, the Arduino IDE has no easy way to work with
> boards that don't use a standard, 16 MHz crystal, as this frequency is used
> by the serial port and, in turn, by the boot loader, so altering it can
> break the ability to upload code. This has actually caused some issues for
> some of my other projects, so I'm investigating how this issue might be
> handled.
>
> Also, if anyone is interested in trying out other modulation schemes, I can
> easily add a compile option t the code that will let it output a binary
> low/high modulation signal instead of the PWM signal.
>
> Wayne
>
> On Thu, Aug 30, 2018 at 8:53 AM paul swed <***@gmail.com> wrote:
>
> > Wayne as I work through the chronverter I do know the good phase tracking
> > clocks really demand on frequency behavior. As I measured its +/- .6 Hz
> at
> > 60 KHz. I believe the cheapy wall clocks are a bit wider, but not sure as
> > they are hard to actually measure. They do use a small tuning fork
> crystal
> > and from experience these are sharp. When I experimented with them they
> > were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals for
> > maybe $2.
> > With respect to the antenna. My thinking is a loopstick resonated on 60
> KHz
> > and most likely driving it push pull or single ended. Thats 1 transistor
> if
> > single ended as common collector if I had to guess. The reason is the
> > micros put out a fair level of signal so its a case of upping current
> into
> > the antenna. But it really will be a bit of experimenting.
> > I did look at your code and that was so nice it opened up straight into
> the
> > arduino IDE.
> > Regards
> > Paul
> > WB8TSL
> >
> > On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <***@gmail.com>
> > wrote:
> >
> > > For anyone trying out my ATTiny85 code, I've done some additional tests
> > and
> > > find that placement of the antenna near the clock is very finicky and,
> so
> > > far, the only way to get a reliable decode of the time in the clock is
> by
> > > using a scope to monitor the demodulated output and then moving the
> > antenna
> > > around until the demodulated signal lines up cleanly with modulated
> > carrier
> > > and there are no intra bit glitches. This can take a bit of patience,
> so
> > > clearly a better solution needs to be found. I've found that any type
> of
> > > glitch in the demodulated signal seems to prevent the clock chip from
> > > decoding the time.
> > >
> > > It's possible the difficultly with locking onto my simulated WWVB
> signal
> > > may be partially due to the design of the clock (from my location it's
> > > never been able to to lock onto the real WWVB signal), but I have no
> > > reference to compare it against so, for now, I have conclude that the
> > > PWM-based modulation scheme my code uses may also be suboptimal for
> this
> > > application. To make testing even more frustrating, the BALDR clock
> I'm
> > > using will only look for a signal for about 6 minutes before it goes to
> > > sleep and I have to then power cycle the clock to get it to listen
> again.
> > >
> > > So, keep this in mind if you're going to try and replicate my results.
> > >
> > > Wayne
> > >
> > > On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <***@gmail.com>
> > > wrote:
> > >
> > > > For those that have asked for my to publish the source code for my
> > > > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly
> > written
> > > > page on my google site at:
> > > >
> > > > https://sites.google.com/site/wayneholder/controlling-time
> > > >
> > > > that describes a bit about how the code works, how to compile it
> using
> > > the
> > > > Arduino IDE, how I tested it, some issues I have observed in testing
> it
> > > > and, at the bottom of the page, a downloadable zip file that contains
> > the
> > > > complete source code.
> > > >
> > > > Note: as mentioned at the top of this page, this is currently a work
> in
> > > > process, so I'm not yet going to link the article to my main website
> > > page,
> > > > so you'll need to link in this post to find it. Also, as draft, I'm
> > > going
> > > > to continue to revise the page until I feel the project is complete
> > > enough
> > > > to publish. That means the source code zip file is going to
> > potentially
> > > > change from time to time, too.
> > > >
> > > > Wayne
> > > >
> > > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <***@gmail.com
> >
> > > > wrote:
> > > >
> > > >> As a follow up, I now have a simple WWVB simulator written in C
> that's
> > > >> now running an an ATTiny85 using nothing more than the internal, 8
> > > >> mHz oscillator and about a 6 inch length of wire connected to one of
> > the
> > > >> pins as an antenna. It generates an approximate 60 kHz signal using
> > > PWM on
> > > >> timer 1. I tweaked the timer value a bit to correct for some
> variance
> > > in
> > > >> the internal oscillator, but I' not even sure that was necessary, as
> > my
> > > >> target is just a BALDR Model B0114ST, consumer grade "Atomic"
> clock.
> > > >> Modulation is done by varying the duty cycle of the PWM to
> approximate
> > > the
> > > >> -17 dBr drop on the carrier. But, again, I don't think this value
> is
> > > >> critical with a consumer clock chip. I tapped the demodulated
> output
> > > >> inside the clock and displayed it on my scope along with the
> generated
> > > >> signal and I got good, steady demodulation with the wire antenna
> just
> > > >> placed near clock. The next step is to connect up a GPS module and
> > add
> > > >> code to use it to set the time. I'm also going to change the code
> to
> > > use
> > > >> the PPS signal from the GPS to drive the output timing rather than
> the
> > > test
> > > >> code I have now that uses timer 0 to generate the PPS interrupt.
> I'm
> > > happy
> > > >> to share details if anyone is interested.
> > > >>
> > > >> Wayne
> > > >>
> > > >>
> > > >>
> > > >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com>
> > wrote:
> > > >>
> > > >>> That would be a great neighbor to have but I can tell you around
> here
> > > its
> > > >>> the phone. Not to concerned about someone putting up a wwvb
> > > replacement.
> > > >>> And I can always up the power. Chickle.
> > > >>> Regards
> > > >>> Paul
> > > >>>
> > > >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org> wrote:
> > > >>>
> > > >>> > Hi
> > > >>> >
> > > >>> > The gotcha is if you have neighbors two or three doors away that
> > > *also*
> > > >>> > put up one of
> > > >>> > these devices. You then have a real problem with the neighbor(s)
> in
> > > the
> > > >>> > middle. The
> > > >>> > wavelength is long enough that Raleigh issues won’t get you. You
> > > still
> > > >>> > have the two
> > > >>> > signals ( at slightly different frequencies) beating against each
> > > >>> other.
> > > >>> > The result is
> > > >>> > going to show up as who knows what to this or that receiver.
> With a
> > > >>> > precision receiver,
> > > >>> > you might even have issues from the guy two houses away …...
> > > >>> >
> > > >>> > Bob
> > > >>> >
> > > >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com>
> > > wrote:
> > > >>> > >
> > > >>> > > Agree with the conversation. With respect to neighbors when the
> > day
> > > >>> comes
> > > >>> > > they may ask you to boost your signal. :-)
> > > >>> > > Granted maybe the day won't come but at least having your local
> > > >>> clocks
> > > >>> > work
> > > >>> > > is nice.
> > > >>> > > Regards
> > > >>> > > Paul
> > > >>> > > WB8TSL
> > > >>> > >
> > > >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> > > >>> ***@gmail.com>
> > > >>> > > wrote:
> > > >>> > >
> > > >>> > >> With the watch being physically close to the faux WWVB
> > > >>> "transmitter",
> > > >>> > one
> > > >>> > >> is in
> > > >>> > >> the so-called "near field" regime, where the field strength
> > (V/m)
> > > >>> falls
> > > >>> > as
> > > >>> > >> the inverse
> > > >>> > >> cube of the distance. If one is putting the watch, say,
> within
> > a
> > > >>> few
> > > >>> > >> inches of the
> > > >>> > >> transmitter, reliable reception should be available yet the
> > signal
> > > >>> > should
> > > >>> > >> be literally
> > > >>> > >> undetectable by any practical receiving device more than a few
> > > feet
> > > >>> > away.
> > > >>> > >> Hence,
> > > >>> > >> meeting the FCC field strength limit should be trivial.if the
> > > >>> device is
> > > >>> > >> used as pictured.
> > > >>> > >> However, if one cranks up the power enough to reliably cover
> > one's
> > > >>> > entire
> > > >>> > >> house,
> > > >>> > >> then there might be a problem depending how close the nearest
> > > >>> neighbor
> > > >>> > >> lives,
> > > >>> > >> even at levels well within the FCC limit he quotes.
> > > >>> > >>
> > > >>> > >> Taking the near field relationship in hand, 40 uV/m at 300m
> > would
> > > >>> > translate
> > > >>> > >> into
> > > >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough to
> > feed
> > > >>> most
> > > >>> > >> peoples'
> > > >>> > >> entire house. So the pragmatic issue would again be-
> neighbors.
> > > >>> On the
> > > >>> > >> other
> > > >>> > >> hand, most of them would never be aware of the local signal as
> > > long
> > > >>> as
> > > >>> > they
> > > >>> > >> get good
> > > >>> > >> time settings, unless they live close enough to Ft. Collins
> for
> > > the
> > > >>> two
> > > >>> > >> signals to
> > > >>> > >> contend with each other.
> > > >>> > >>
> > > >>> > >> It looks to me like the ferrite rod antenna is considerable
> > > >>> overkill.
> > > >>> > Even
> > > >>> > >> with no
> > > >>> > >> purposeful antenna I'd expect leakage to yield sufficient
> signal
> > > >>> for at
> > > >>> > >> least a few
> > > >>> > >> inches.
> > > >>> > >>
> > > >>> > >> Dana
> > > >>> > >>
> > > >>> > >>
> > > >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> > > >>> ***@gmail.com>
> > > >>> > >> wrote:
> > > >>> > >>
> > > >>> > >>> This guy has what looks like a well thought out design using
> a
> > > >>> > Sirf-Based
> > > >>> > >>> GPS and ATTiny44A chip to generate a signal to update his
> > watch:
> > > >>> > >>>
> > > >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> > > >>> > >>>
> > > >>> > >>> Unfortunately, he doesn't seem to have published a schematic
> or
> > > his
> > > >>> > >> source
> > > >>> > >>> code. But, he covers enough detail that I think it wouldn't
> be
> > > too
> > > >>> > hard
> > > >>> > >> to
> > > >>> > >>> replicate what he's done. Or, perhaps he would disclose
> these
> > > >>> details
> > > >>> > if
> > > >>> > >>> contacted.
> > > >>> > >>>
> > > >>> > >>> Wayne
> > > >>> > >>>
> > > >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
> > > ***@pacbell.net>
> > > >>> > >> wrote:
> > > >>> > >>>
> > > >>> > >>>> I thought I would search in a different way for a WWVB
> signal
> > > >>> > generator
> > > >>> > >>>> design. I found this item. While the designer explains it
> > > isn't
> > > >>> as
> > > >>> > >>>> accurate as WWVB it may be another starting point.
> > > >>> > >>>>
> > > >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> > > >>> > signal-generator.htm
> > > >>> > >>>>
> > > >>> > >>>>
> > > >>> > >>>>
> > > >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > > >>> > >>>> http://hammondorganservice.com
> > > >>> > >>>> Hammond USA warranty service
> > > >>> > >>>> "Most people don't have a sense of humor. They think they
> do,
> > > but
> > > >>> they
> > > >>> > >>>> don't." --Jonathan Winters
> > > >>> > >>>>
> > > >>> > >>>> _______________________________________________
> > > >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
> > > >>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> > > >>> > >>>> listinfo/time-nuts_lists.febo.com
> > > >>> > >>>> and follow the instructions there.
> > > >>> > >>>>
> > > >>> > >>> _______________________________________________
> > > >>> > >>> time-nuts mailing list -- time-***@lists.febo.com
> > > >>> > >>> To unsubscribe, go to
> > > >>> > >>>
> > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
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> > > >>> > >>>
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and follow
Wayne Holder
2018-08-31 06:45:12 UTC
Permalink
> Wayne very good progress. You can actually feed the loop coild that exists
> with the cap it should resonate.
> Thats my plan at least.

Thanks, Paul. Actually, after running a few more tests, the BALDR seems to
now set quite reliably with the wire just wrapped around the ferrite rod as
long as the clock is with 2 inches of the ferrite rod. I'm using the WWVB
receiver module in another experiment, so I don't want to risk damaging the
module by applying a 5 volt PVM signal to the coil. But, I have a another
WWVB receiver module on order so, once it arrives, I'll try out your
suggestion. I've also ordered some ferrite rods in order try my hand at
rolling a 60 kHz antenna from scratch, so that will be another adventure.

Wayne


On Thu, Aug 30, 2018 at 8:04 PM paul swed <***@gmail.com> wrote:

> Wayne very good progress. You can actually feed the loop coild that exists
> with the cap it should resonate.
> Thats my plan at least.
> Regards
> Paul
> WB8TSL
>
> On Thu, Aug 30, 2018 at 9:44 PM, Wayne Holder <***@gmail.com>
> wrote:
>
> > I've had some luck improving things with my ATTiny85-based WWVB Simulator
> > design by replacing the crappy, 8 MHz internal oscillator with an 8 MHz
> > crystal and removing the tweaked timer values I had previously used. In
> > addition, based on a suggestion from Paul Swed, I tried looping the
> antenna
> > wire a few times around the ferrite rod of a WWVB receiver module I
> > happened to have lying around and this also greatly improved things (see
> > photo on web page at
> > https://sites.google.com/site/wayneholder/controlling-time). In fact,
> > with
> > the ferrite rod in place, the BALDR clock now syncs even when completely
> > disconnected from being grounded to the ATTiny85 and the scope.
> >
> > I've updated my web page, and the source code at the bottom of the page,
> > accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS
> output
> > is currently disabled in the code. In addition, I've added some
> additional
> > info on my web page about how to compile and download the program to an
> > ATTiny85 using ATTinyCore by Spence Konde.
> >
> > I've ordered a 15.36 MHz crystal to try, as that should let the ATTiny85
> > generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has
> helped
> > improve things quite a bit. In addition, I plan to do more tests on
> > different types of antennas in order to see if I can make things even
> more
> > reliable and stable.
> >
> > I still plan on reworking the code so it can also run on a 328-based
> > Arduino board but, currently, the Arduino IDE has no easy way to work
> with
> > boards that don't use a standard, 16 MHz crystal, as this frequency is
> used
> > by the serial port and, in turn, by the boot loader, so altering it can
> > break the ability to upload code. This has actually caused some issues
> for
> > some of my other projects, so I'm investigating how this issue might be
> > handled.
> >
> > Also, if anyone is interested in trying out other modulation schemes, I
> can
> > easily add a compile option t the code that will let it output a binary
> > low/high modulation signal instead of the PWM signal.
> >
> > Wayne
> >
> > On Thu, Aug 30, 2018 at 8:53 AM paul swed <***@gmail.com> wrote:
> >
> > > Wayne as I work through the chronverter I do know the good phase
> tracking
> > > clocks really demand on frequency behavior. As I measured its +/- .6 Hz
> > at
> > > 60 KHz. I believe the cheapy wall clocks are a bit wider, but not sure
> as
> > > they are hard to actually measure. They do use a small tuning fork
> > crystal
> > > and from experience these are sharp. When I experimented with them they
> > > were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals
> for
> > > maybe $2.
> > > With respect to the antenna. My thinking is a loopstick resonated on 60
> > KHz
> > > and most likely driving it push pull or single ended. Thats 1
> transistor
> > if
> > > single ended as common collector if I had to guess. The reason is the
> > > micros put out a fair level of signal so its a case of upping current
> > into
> > > the antenna. But it really will be a bit of experimenting.
> > > I did look at your code and that was so nice it opened up straight into
> > the
> > > arduino IDE.
> > > Regards
> > > Paul
> > > WB8TSL
> > >
> > > On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <***@gmail.com>
> > > wrote:
> > >
> > > > For anyone trying out my ATTiny85 code, I've done some additional
> tests
> > > and
> > > > find that placement of the antenna near the clock is very finicky
> and,
> > so
> > > > far, the only way to get a reliable decode of the time in the clock
> is
> > by
> > > > using a scope to monitor the demodulated output and then moving the
> > > antenna
> > > > around until the demodulated signal lines up cleanly with modulated
> > > carrier
> > > > and there are no intra bit glitches. This can take a bit of
> patience,
> > so
> > > > clearly a better solution needs to be found. I've found that any
> type
> > of
> > > > glitch in the demodulated signal seems to prevent the clock chip from
> > > > decoding the time.
> > > >
> > > > It's possible the difficultly with locking onto my simulated WWVB
> > signal
> > > > may be partially due to the design of the clock (from my location
> it's
> > > > never been able to to lock onto the real WWVB signal), but I have no
> > > > reference to compare it against so, for now, I have conclude that the
> > > > PWM-based modulation scheme my code uses may also be suboptimal for
> > this
> > > > application. To make testing even more frustrating, the BALDR clock
> > I'm
> > > > using will only look for a signal for about 6 minutes before it goes
> to
> > > > sleep and I have to then power cycle the clock to get it to listen
> > again.
> > > >
> > > > So, keep this in mind if you're going to try and replicate my
> results.
> > > >
> > > > Wayne
> > > >
> > > > On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <***@gmail.com
> >
> > > > wrote:
> > > >
> > > > > For those that have asked for my to publish the source code for my
> > > > > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly
> > > written
> > > > > page on my google site at:
> > > > >
> > > > > https://sites.google.com/site/wayneholder/controlling-time
> > > > >
> > > > > that describes a bit about how the code works, how to compile it
> > using
> > > > the
> > > > > Arduino IDE, how I tested it, some issues I have observed in
> testing
> > it
> > > > > and, at the bottom of the page, a downloadable zip file that
> contains
> > > the
> > > > > complete source code.
> > > > >
> > > > > Note: as mentioned at the top of this page, this is currently a
> work
> > in
> > > > > process, so I'm not yet going to link the article to my main
> website
> > > > page,
> > > > > so you'll need to link in this post to find it. Also, as draft,
> I'm
> > > > going
> > > > > to continue to revise the page until I feel the project is complete
> > > > enough
> > > > > to publish. That means the source code zip file is going to
> > > potentially
> > > > > change from time to time, too.
> > > > >
> > > > > Wayne
> > > > >
> > > > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <
> ***@gmail.com
> > >
> > > > > wrote:
> > > > >
> > > > >> As a follow up, I now have a simple WWVB simulator written in C
> > that's
> > > > >> now running an an ATTiny85 using nothing more than the internal, 8
> > > > >> mHz oscillator and about a 6 inch length of wire connected to one
> of
> > > the
> > > > >> pins as an antenna. It generates an approximate 60 kHz signal
> using
> > > > PWM on
> > > > >> timer 1. I tweaked the timer value a bit to correct for some
> > variance
> > > > in
> > > > >> the internal oscillator, but I' not even sure that was necessary,
> as
> > > my
> > > > >> target is just a BALDR Model B0114ST, consumer grade "Atomic"
> > clock.
> > > > >> Modulation is done by varying the duty cycle of the PWM to
> > approximate
> > > > the
> > > > >> -17 dBr drop on the carrier. But, again, I don't think this value
> > is
> > > > >> critical with a consumer clock chip. I tapped the demodulated
> > output
> > > > >> inside the clock and displayed it on my scope along with the
> > generated
> > > > >> signal and I got good, steady demodulation with the wire antenna
> > just
> > > > >> placed near clock. The next step is to connect up a GPS module
> and
> > > add
> > > > >> code to use it to set the time. I'm also going to change the code
> > to
> > > > use
> > > > >> the PPS signal from the GPS to drive the output timing rather than
> > the
> > > > test
> > > > >> code I have now that uses timer 0 to generate the PPS interrupt.
> > I'm
> > > > happy
> > > > >> to share details if anyone is interested.
> > > > >>
> > > > >> Wayne
> > > > >>
> > > > >>
> > > > >>
> > > > >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com>
> > > wrote:
> > > > >>
> > > > >>> That would be a great neighbor to have but I can tell you around
> > here
> > > > its
> > > > >>> the phone. Not to concerned about someone putting up a wwvb
> > > > replacement.
> > > > >>> And I can always up the power. Chickle.
> > > > >>> Regards
> > > > >>> Paul
> > > > >>>
> > > > >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org>
> wrote:
> > > > >>>
> > > > >>> > Hi
> > > > >>> >
> > > > >>> > The gotcha is if you have neighbors two or three doors away
> that
> > > > *also*
> > > > >>> > put up one of
> > > > >>> > these devices. You then have a real problem with the
> neighbor(s)
> > in
> > > > the
> > > > >>> > middle. The
> > > > >>> > wavelength is long enough that Raleigh issues won’t get you.
> You
> > > > still
> > > > >>> > have the two
> > > > >>> > signals ( at slightly different frequencies) beating against
> each
> > > > >>> other.
> > > > >>> > The result is
> > > > >>> > going to show up as who knows what to this or that receiver.
> > With a
> > > > >>> > precision receiver,
> > > > >>> > you might even have issues from the guy two houses away …...
> > > > >>> >
> > > > >>> > Bob
> > > > >>> >
> > > > >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com>
> > > > wrote:
> > > > >>> > >
> > > > >>> > > Agree with the conversation. With respect to neighbors when
> the
> > > day
> > > > >>> comes
> > > > >>> > > they may ask you to boost your signal. :-)
> > > > >>> > > Granted maybe the day won't come but at least having your
> local
> > > > >>> clocks
> > > > >>> > work
> > > > >>> > > is nice.
> > > > >>> > > Regards
> > > > >>> > > Paul
> > > > >>> > > WB8TSL
> > > > >>> > >
> > > > >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> > > > >>> ***@gmail.com>
> > > > >>> > > wrote:
> > > > >>> > >
> > > > >>> > >> With the watch being physically close to the faux WWVB
> > > > >>> "transmitter",
> > > > >>> > one
> > > > >>> > >> is in
> > > > >>> > >> the so-called "near field" regime, where the field strength
> > > (V/m)
> > > > >>> falls
> > > > >>> > as
> > > > >>> > >> the inverse
> > > > >>> > >> cube of the distance. If one is putting the watch, say,
> > within
> > > a
> > > > >>> few
> > > > >>> > >> inches of the
> > > > >>> > >> transmitter, reliable reception should be available yet the
> > > signal
> > > > >>> > should
> > > > >>> > >> be literally
> > > > >>> > >> undetectable by any practical receiving device more than a
> few
> > > > feet
> > > > >>> > away.
> > > > >>> > >> Hence,
> > > > >>> > >> meeting the FCC field strength limit should be trivial.if
> the
> > > > >>> device is
> > > > >>> > >> used as pictured.
> > > > >>> > >> However, if one cranks up the power enough to reliably cover
> > > one's
> > > > >>> > entire
> > > > >>> > >> house,
> > > > >>> > >> then there might be a problem depending how close the
> nearest
> > > > >>> neighbor
> > > > >>> > >> lives,
> > > > >>> > >> even at levels well within the FCC limit he quotes.
> > > > >>> > >>
> > > > >>> > >> Taking the near field relationship in hand, 40 uV/m at 300m
> > > would
> > > > >>> > translate
> > > > >>> > >> into
> > > > >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough to
> > > feed
> > > > >>> most
> > > > >>> > >> peoples'
> > > > >>> > >> entire house. So the pragmatic issue would again be-
> > neighbors.
> > > > >>> On the
> > > > >>> > >> other
> > > > >>> > >> hand, most of them would never be aware of the local signal
> as
> > > > long
> > > > >>> as
> > > > >>> > they
> > > > >>> > >> get good
> > > > >>> > >> time settings, unless they live close enough to Ft. Collins
> > for
> > > > the
> > > > >>> two
> > > > >>> > >> signals to
> > > > >>> > >> contend with each other.
> > > > >>> > >>
> > > > >>> > >> It looks to me like the ferrite rod antenna is considerable
> > > > >>> overkill.
> > > > >>> > Even
> > > > >>> > >> with no
> > > > >>> > >> purposeful antenna I'd expect leakage to yield sufficient
> > signal
> > > > >>> for at
> > > > >>> > >> least a few
> > > > >>> > >> inches.
> > > > >>> > >>
> > > > >>> > >> Dana
> > > > >>> > >>
> > > > >>> > >>
> > > > >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> > > > >>> ***@gmail.com>
> > > > >>> > >> wrote:
> > > > >>> > >>
> > > > >>> > >>> This guy has what looks like a well thought out design
> using
> > a
> > > > >>> > Sirf-Based
> > > > >>> > >>> GPS and ATTiny44A chip to generate a signal to update his
> > > watch:
> > > > >>> > >>>
> > > > >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> > > > >>> > >>>
> > > > >>> > >>> Unfortunately, he doesn't seem to have published a
> schematic
> > or
> > > > his
> > > > >>> > >> source
> > > > >>> > >>> code. But, he covers enough detail that I think it
> wouldn't
> > be
> > > > too
> > > > >>> > hard
> > > > >>> > >> to
> > > > >>> > >>> replicate what he's done. Or, perhaps he would disclose
> > these
> > > > >>> details
> > > > >>> > if
> > > > >>> > >>> contacted.
> > > > >>> > >>>
> > > > >>> > >>> Wayne
> > > > >>> > >>>
> > > > >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
> > > > ***@pacbell.net>
> > > > >>> > >> wrote:
> > > > >>> > >>>
> > > > >>> > >>>> I thought I would search in a different way for a WWVB
> > signal
> > > > >>> > generator
> > > > >>> > >>>> design. I found this item. While the designer explains
> it
> > > > isn't
> > > > >>> as
> > > > >>> > >>>> accurate as WWVB it may be another starting point.
> > > > >>> > >>>>
> > > > >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> > > > >>> > signal-generator.htm
> > > > >>> > >>>>
> > > > >>> > >>>>
> > > > >>> > >>>>
> > > > >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > > > >>> > >>>> http://hammondorganservice.com
> > > > >>> > >>>> Hammond USA warranty service
> > > > >>> > >>>> "Most people don't have a sense of humor. They think they
> > do,
> > > > but
> > > > >>> they
> > > > >>> > >>>> don't." --Jonathan Winters
> > > > >>> > >>>>
> > > > >>> > >>>> _______________________________________________
> > > > >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> > > > >>> > >>>> listinfo/time-nuts_lists.febo.com
> > > > >>> > >>>> and follow the instructions there.
> > > > >>> > >>>>
> > > > >>> > >>> _______________________________________________
> > > > >>> > >>> time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> > >>> To unsubscribe, go to
> > > > >>> > >>>
> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > > >>> > >>> and follow the instructions there.
> > > > >>> > >>>
> > > > >>> > >> _______________________________________________
> > > > >>> > >> time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> > >> To unsubscribe, go to http://lists.febo.com/mailman/
> > > > >>> > >> listinfo/time-nuts_lists.febo.com
> > > > >>> > >> and follow the instructions there.
> > > > >>> > >>
> > > > >>> > > _______________________________________________
> > > > >>> > > time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > > >>> > listinfo/time-nuts_lists.febo.com
> > > > >>> > > and follow the instructions there.
> > > > >>> >
> > > > >>> >
> > > > >>> > _______________________________________________
> > > > >>> > time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> > To unsubscribe, go to http://lists.febo.com/mailman/
> > > > >>> > listinfo/time-nuts_lists.febo.com
> > > > >>> > and follow the instructions there.
> > > > >>> >
> > > > >>> _______________________________________________
> > > > >>> time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> To unsubscribe, go to
> > > > >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > > >>> and follow the instructions there.
> > > > >>>
> > > > >>
> > > > >>
> > > > _______________________________________________
> > > > time-nuts mailing list -- time-***@lists.febo.com
> > > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > > listinfo/time-nuts_lists.febo.com
> > > > and follow the instructions there.
> > > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to
> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
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> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
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and foll
Wayne Holder
2018-09-02 00:14:27 UTC
Permalink
My 15.36 MHz crystals arrived and using one to replace the 8 MHz crystal
seems to, again, improve the ability of the BALDR clock to lock onto and
decode the signal. It now reliably syncs if the clock is within 6-7 inches
of the tuned, ferrite rod antenna (still just wrapping the wire around the
rod.) With just a loose, wire antenna, the clock syncs if the antenna is
with 2-3 inches of the clock, which is also an improvement.

I'm also starting to work on moving the code over to an Arduino using an
old Duemilanove board I had lying around, as ithe crystal it uses is a
standard, HC-49 package, which makes it easer to replace than the surface
mount crystals used on modern Arduino boards (you can also get a cheap clone
of the Duemilanove on eBay
<https://www.ebay.com/itm/Duemilanove-USB-Board-2009-ATMega328P-PU-Microcontroller-Compatible-With-Arduino/182256700970>
for
about $6 + shipping.) And, as near as I can tell, 15.36 MHz is close
enough to 16 MHz that I didn't have to modify the boot loader and uploads
seem to work ok. Just swap the crystal and go. So, that's one less thing
to worry about.

Wayne

On Thu, Aug 30, 2018 at 8:04 PM paul swed <***@gmail.com> wrote:

> Wayne very good progress. You can actually feed the loop coild that exists
> with the cap it should resonate.
> Thats my plan at least.
> Regards
> Paul
> WB8TSL
>
> On Thu, Aug 30, 2018 at 9:44 PM, Wayne Holder <***@gmail.com>
> wrote:
>
> > I've had some luck improving things with my ATTiny85-based WWVB Simulator
> > design by replacing the crappy, 8 MHz internal oscillator with an 8 MHz
> > crystal and removing the tweaked timer values I had previously used. In
> > addition, based on a suggestion from Paul Swed, I tried looping the
> antenna
> > wire a few times around the ferrite rod of a WWVB receiver module I
> > happened to have lying around and this also greatly improved things (see
> > photo on web page at
> > https://sites.google.com/site/wayneholder/controlling-time). In fact,
> > with
> > the ferrite rod in place, the BALDR clock now syncs even when completely
> > disconnected from being grounded to the ATTiny85 and the scope.
> >
> > I've updated my web page, and the source code at the bottom of the page,
> > accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS
> output
> > is currently disabled in the code. In addition, I've added some
> additional
> > info on my web page about how to compile and download the program to an
> > ATTiny85 using ATTinyCore by Spence Konde.
> >
> > I've ordered a 15.36 MHz crystal to try, as that should let the ATTiny85
> > generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has
> helped
> > improve things quite a bit. In addition, I plan to do more tests on
> > different types of antennas in order to see if I can make things even
> more
> > reliable and stable.
> >
> > I still plan on reworking the code so it can also run on a 328-based
> > Arduino board but, currently, the Arduino IDE has no easy way to work
> with
> > boards that don't use a standard, 16 MHz crystal, as this frequency is
> used
> > by the serial port and, in turn, by the boot loader, so altering it can
> > break the ability to upload code. This has actually caused some issues
> for
> > some of my other projects, so I'm investigating how this issue might be
> > handled.
> >
> > Also, if anyone is interested in trying out other modulation schemes, I
> can
> > easily add a compile option t the code that will let it output a binary
> > low/high modulation signal instead of the PWM signal.
> >
> > Wayne
> >
> > On Thu, Aug 30, 2018 at 8:53 AM paul swed <***@gmail.com> wrote:
> >
> > > Wayne as I work through the chronverter I do know the good phase
> tracking
> > > clocks really demand on frequency behavior. As I measured its +/- .6 Hz
> > at
> > > 60 KHz. I believe the cheapy wall clocks are a bit wider, but not sure
> as
> > > they are hard to actually measure. They do use a small tuning fork
> > crystal
> > > and from experience these are sharp. When I experimented with them they
> > > were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals
> for
> > > maybe $2.
> > > With respect to the antenna. My thinking is a loopstick resonated on 60
> > KHz
> > > and most likely driving it push pull or single ended. Thats 1
> transistor
> > if
> > > single ended as common collector if I had to guess. The reason is the
> > > micros put out a fair level of signal so its a case of upping current
> > into
> > > the antenna. But it really will be a bit of experimenting.
> > > I did look at your code and that was so nice it opened up straight into
> > the
> > > arduino IDE.
> > > Regards
> > > Paul
> > > WB8TSL
> > >
> > > On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <***@gmail.com>
> > > wrote:
> > >
> > > > For anyone trying out my ATTiny85 code, I've done some additional
> tests
> > > and
> > > > find that placement of the antenna near the clock is very finicky
> and,
> > so
> > > > far, the only way to get a reliable decode of the time in the clock
> is
> > by
> > > > using a scope to monitor the demodulated output and then moving the
> > > antenna
> > > > around until the demodulated signal lines up cleanly with modulated
> > > carrier
> > > > and there are no intra bit glitches. This can take a bit of
> patience,
> > so
> > > > clearly a better solution needs to be found. I've found that any
> type
> > of
> > > > glitch in the demodulated signal seems to prevent the clock chip from
> > > > decoding the time.
> > > >
> > > > It's possible the difficultly with locking onto my simulated WWVB
> > signal
> > > > may be partially due to the design of the clock (from my location
> it's
> > > > never been able to to lock onto the real WWVB signal), but I have no
> > > > reference to compare it against so, for now, I have conclude that the
> > > > PWM-based modulation scheme my code uses may also be suboptimal for
> > this
> > > > application. To make testing even more frustrating, the BALDR clock
> > I'm
> > > > using will only look for a signal for about 6 minutes before it goes
> to
> > > > sleep and I have to then power cycle the clock to get it to listen
> > again.
> > > >
> > > > So, keep this in mind if you're going to try and replicate my
> results.
> > > >
> > > > Wayne
> > > >
> > > > On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <***@gmail.com
> >
> > > > wrote:
> > > >
> > > > > For those that have asked for my to publish the source code for my
> > > > > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly
> > > written
> > > > > page on my google site at:
> > > > >
> > > > > https://sites.google.com/site/wayneholder/controlling-time
> > > > >
> > > > > that describes a bit about how the code works, how to compile it
> > using
> > > > the
> > > > > Arduino IDE, how I tested it, some issues I have observed in
> testing
> > it
> > > > > and, at the bottom of the page, a downloadable zip file that
> contains
> > > the
> > > > > complete source code.
> > > > >
> > > > > Note: as mentioned at the top of this page, this is currently a
> work
> > in
> > > > > process, so I'm not yet going to link the article to my main
> website
> > > > page,
> > > > > so you'll need to link in this post to find it. Also, as draft,
> I'm
> > > > going
> > > > > to continue to revise the page until I feel the project is complete
> > > > enough
> > > > > to publish. That means the source code zip file is going to
> > > potentially
> > > > > change from time to time, too.
> > > > >
> > > > > Wayne
> > > > >
> > > > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <
> ***@gmail.com
> > >
> > > > > wrote:
> > > > >
> > > > >> As a follow up, I now have a simple WWVB simulator written in C
> > that's
> > > > >> now running an an ATTiny85 using nothing more than the internal, 8
> > > > >> mHz oscillator and about a 6 inch length of wire connected to one
> of
> > > the
> > > > >> pins as an antenna. It generates an approximate 60 kHz signal
> using
> > > > PWM on
> > > > >> timer 1. I tweaked the timer value a bit to correct for some
> > variance
> > > > in
> > > > >> the internal oscillator, but I' not even sure that was necessary,
> as
> > > my
> > > > >> target is just a BALDR Model B0114ST, consumer grade "Atomic"
> > clock.
> > > > >> Modulation is done by varying the duty cycle of the PWM to
> > approximate
> > > > the
> > > > >> -17 dBr drop on the carrier. But, again, I don't think this value
> > is
> > > > >> critical with a consumer clock chip. I tapped the demodulated
> > output
> > > > >> inside the clock and displayed it on my scope along with the
> > generated
> > > > >> signal and I got good, steady demodulation with the wire antenna
> > just
> > > > >> placed near clock. The next step is to connect up a GPS module
> and
> > > add
> > > > >> code to use it to set the time. I'm also going to change the code
> > to
> > > > use
> > > > >> the PPS signal from the GPS to drive the output timing rather than
> > the
> > > > test
> > > > >> code I have now that uses timer 0 to generate the PPS interrupt.
> > I'm
> > > > happy
> > > > >> to share details if anyone is interested.
> > > > >>
> > > > >> Wayne
> > > > >>
> > > > >>
> > > > >>
> > > > >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com>
> > > wrote:
> > > > >>
> > > > >>> That would be a great neighbor to have but I can tell you around
> > here
> > > > its
> > > > >>> the phone. Not to concerned about someone putting up a wwvb
> > > > replacement.
> > > > >>> And I can always up the power. Chickle.
> > > > >>> Regards
> > > > >>> Paul
> > > > >>>
> > > > >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org>
> wrote:
> > > > >>>
> > > > >>> > Hi
> > > > >>> >
> > > > >>> > The gotcha is if you have neighbors two or three doors away
> that
> > > > *also*
> > > > >>> > put up one of
> > > > >>> > these devices. You then have a real problem with the
> neighbor(s)
> > in
> > > > the
> > > > >>> > middle. The
> > > > >>> > wavelength is long enough that Raleigh issues won’t get you.
> You
> > > > still
> > > > >>> > have the two
> > > > >>> > signals ( at slightly different frequencies) beating against
> each
> > > > >>> other.
> > > > >>> > The result is
> > > > >>> > going to show up as who knows what to this or that receiver.
> > With a
> > > > >>> > precision receiver,
> > > > >>> > you might even have issues from the guy two houses away …...
> > > > >>> >
> > > > >>> > Bob
> > > > >>> >
> > > > >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com>
> > > > wrote:
> > > > >>> > >
> > > > >>> > > Agree with the conversation. With respect to neighbors when
> the
> > > day
> > > > >>> comes
> > > > >>> > > they may ask you to boost your signal. :-)
> > > > >>> > > Granted maybe the day won't come but at least having your
> local
> > > > >>> clocks
> > > > >>> > work
> > > > >>> > > is nice.
> > > > >>> > > Regards
> > > > >>> > > Paul
> > > > >>> > > WB8TSL
> > > > >>> > >
> > > > >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> > > > >>> ***@gmail.com>
> > > > >>> > > wrote:
> > > > >>> > >
> > > > >>> > >> With the watch being physically close to the faux WWVB
> > > > >>> "transmitter",
> > > > >>> > one
> > > > >>> > >> is in
> > > > >>> > >> the so-called "near field" regime, where the field strength
> > > (V/m)
> > > > >>> falls
> > > > >>> > as
> > > > >>> > >> the inverse
> > > > >>> > >> cube of the distance. If one is putting the watch, say,
> > within
> > > a
> > > > >>> few
> > > > >>> > >> inches of the
> > > > >>> > >> transmitter, reliable reception should be available yet the
> > > signal
> > > > >>> > should
> > > > >>> > >> be literally
> > > > >>> > >> undetectable by any practical receiving device more than a
> few
> > > > feet
> > > > >>> > away.
> > > > >>> > >> Hence,
> > > > >>> > >> meeting the FCC field strength limit should be trivial.if
> the
> > > > >>> device is
> > > > >>> > >> used as pictured.
> > > > >>> > >> However, if one cranks up the power enough to reliably cover
> > > one's
> > > > >>> > entire
> > > > >>> > >> house,
> > > > >>> > >> then there might be a problem depending how close the
> nearest
> > > > >>> neighbor
> > > > >>> > >> lives,
> > > > >>> > >> even at levels well within the FCC limit he quotes.
> > > > >>> > >>
> > > > >>> > >> Taking the near field relationship in hand, 40 uV/m at 300m
> > > would
> > > > >>> > translate
> > > > >>> > >> into
> > > > >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough to
> > > feed
> > > > >>> most
> > > > >>> > >> peoples'
> > > > >>> > >> entire house. So the pragmatic issue would again be-
> > neighbors.
> > > > >>> On the
> > > > >>> > >> other
> > > > >>> > >> hand, most of them would never be aware of the local signal
> as
> > > > long
> > > > >>> as
> > > > >>> > they
> > > > >>> > >> get good
> > > > >>> > >> time settings, unless they live close enough to Ft. Collins
> > for
> > > > the
> > > > >>> two
> > > > >>> > >> signals to
> > > > >>> > >> contend with each other.
> > > > >>> > >>
> > > > >>> > >> It looks to me like the ferrite rod antenna is considerable
> > > > >>> overkill.
> > > > >>> > Even
> > > > >>> > >> with no
> > > > >>> > >> purposeful antenna I'd expect leakage to yield sufficient
> > signal
> > > > >>> for at
> > > > >>> > >> least a few
> > > > >>> > >> inches.
> > > > >>> > >>
> > > > >>> > >> Dana
> > > > >>> > >>
> > > > >>> > >>
> > > > >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> > > > >>> ***@gmail.com>
> > > > >>> > >> wrote:
> > > > >>> > >>
> > > > >>> > >>> This guy has what looks like a well thought out design
> using
> > a
> > > > >>> > Sirf-Based
> > > > >>> > >>> GPS and ATTiny44A chip to generate a signal to update his
> > > watch:
> > > > >>> > >>>
> > > > >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> > > > >>> > >>>
> > > > >>> > >>> Unfortunately, he doesn't seem to have published a
> schematic
> > or
> > > > his
> > > > >>> > >> source
> > > > >>> > >>> code. But, he covers enough detail that I think it
> wouldn't
> > be
> > > > too
> > > > >>> > hard
> > > > >>> > >> to
> > > > >>> > >>> replicate what he's done. Or, perhaps he would disclose
> > these
> > > > >>> details
> > > > >>> > if
> > > > >>> > >>> contacted.
> > > > >>> > >>>
> > > > >>> > >>> Wayne
> > > > >>> > >>>
> > > > >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
> > > > ***@pacbell.net>
> > > > >>> > >> wrote:
> > > > >>> > >>>
> > > > >>> > >>>> I thought I would search in a different way for a WWVB
> > signal
> > > > >>> > generator
> > > > >>> > >>>> design. I found this item. While the designer explains
> it
> > > > isn't
> > > > >>> as
> > > > >>> > >>>> accurate as WWVB it may be another starting point.
> > > > >>> > >>>>
> > > > >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> > > > >>> > signal-generator.htm
> > > > >>> > >>>>
> > > > >>> > >>>>
> > > > >>> > >>>>
> > > > >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> > > > >>> > >>>> http://hammondorganservice.com
> > > > >>> > >>>> Hammond USA warranty service
> > > > >>> > >>>> "Most people don't have a sense of humor. They think they
> > do,
> > > > but
> > > > >>> they
> > > > >>> > >>>> don't." --Jonathan Winters
> > > > >>> > >>>>
> > > > >>> > >>>> _______________________________________________
> > > > >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> > > > >>> > >>>> listinfo/time-nuts_lists.febo.com
> > > > >>> > >>>> and follow the instructions there.
> > > > >>> > >>>>
> > > > >>> > >>> _______________________________________________
> > > > >>> > >>> time-nuts mailing list -- time-***@lists.febo.com
> > > > >>> > >>> To unsubscribe, go to
> > > > >>> > >>>
> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > > >>> > >>> and follow the instructions there.
> > > > >>> > >>>
> > > > >>> > >> _______________________________________________
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> > > > >>> > _______________________________________________
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and follow the instructions
Wayne Holder
2018-09-05 10:01:34 UTC
Permalink
I've reworked my WWVB Simulator so it can now run on a slightly modified,
328-based Arduino (swapped in a 16.36 MHz crystal for the standard 16 MHz.)
The new code is also now using a GPS module to set the time from the
GPS $GPRMC message and my BALDR clock just syncs up nicely. I used a
GlobalTopGPS module (similar to the one used in this Adafruit GPS module
<https://www.adafruit.com/product/746>) but, with minor changes, it should
work with any GPS module. The main change needed is configuring the
message used to set the module to only send $GPRMC messages (at a 1 second
interval) and suppress the others NMEA messages.

The last step is to to set the DST status bits (57 and 58) in the WWVB
message, but I'm little bit confused as to when to precisely set these
bits. For reference, the the Java code (below) that I used to prototype
and test the algorithms before converting to C. The code computes the
starting day of year and ending day of year and the idea is to use these
two DOY values to control to setting bits 57 and 58. But, it's unclear to
me if I should set starting and ending state (code 2 and 1, respectively)
on the Sunday of the change or on the days before and after this date? Or,
are the starting and ending states set on Sunday and the other states on
the following Mondays? I'm confused.

Wayne

public class DaylightSavings {
private static final int daysToMonth[][] = {
{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 },
{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 },
};
private static final int MARCH = 3;
private static final int NOVEMBER = 11;

/*
* Compute state and end of Daylight Savings time for specified 4 digit year
* DST Starts the 2nd Sunday of March at 2:00 AM
* DST Ends the first Sunday of November at 1:00 AM
*/

public static void main (String[] args) {
int year = 2018;
int start = getNthSundayOfMonth(2, MARCH, year); //
Get 2nd Sunday of March
int end = getNthSundayOfMonth(1, NOVEMBER, year); //
Get 1st Sunday of November
int startDoy = getDayOfYear(start, MARCH, isLeapYear(year));
int endDoy = getDayOfYear(end, NOVEMBER, isLeapYear(year));
System.out.println("DST starts: " + MARCH + "/" + start + "/" +
year + " (Day of Year: " + startDoy + ") ");
System.out.println("DST ends: " + NOVEMBER + "/" + end + "/" +
year + " (Day of Year: " + endDoy + ")");
}

private static int getNthSundayOfMonth (int sundays, int month, int year) {
for (int day = 1; day < 15; day++) {
if (getDayOfWeek(month, day, year) == 2) {
if (--sundays == 0) {
return day;
}
}
}
// Should never get here
return 0;
}

private static int getDayOfYear (int day, int month, boolean leapYear) {
return daysToMonth[leapYear ? 1 : 0][month - 1] + day;
}

private static boolean isLeapYear (int year) {
return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
}

/**
* Compute Day Of Week (1-7) using Zeller's Method
* @param month (1-12)
* @param day (1-n)
* @param year 4 digit year
* @return day of week (1 = Sat, 2 = Su, 3 = Mon, 4 = Tue, 5 = Wed,
6 = Thr, 7 = Fri
*/
private static int getDayOfWeek ( int month, int day, int year) {
int cen = year / 100;
year = year % 100;
if (month == 1) {
month = 13;
year--;
} else if (month == 2) {
month = 14;
year--;
}
return (day + 13 * (month + 1) / 5 + year + year / 4 + cen / 4 + 5
* cen) % 7 + 1;
}
}


On Sat, Sep 1, 2018 at 5:14 PM Wayne Holder <***@gmail.com> wrote:

> My 15.36 MHz crystals arrived and using one to replace the 8 MHz crystal
> seems to, again, improve the ability of the BALDR clock to lock onto and
> decode the signal. It now reliably syncs if the clock is within 6-7 inches
> of the tuned, ferrite rod antenna (still just wrapping the wire around the
> rod.) With just a loose, wire antenna, the clock syncs if the antenna is
> with 2-3 inches of the clock, which is also an improvement.
>
> I'm also starting to work on moving the code over to an Arduino using an
> old Duemilanove board I had lying around, as ithe crystal it uses is a
> standard, HC-49 package, which makes it easer to replace than the surface
> mount crystals used on modern Arduino boards (you can also get a cheap clone
> of the Duemilanove on eBay
> <https://www.ebay.com/itm/Duemilanove-USB-Board-2009-ATMega328P-PU-Microcontroller-Compatible-With-Arduino/182256700970> for
> about $6 + shipping.) And, as near as I can tell, 15.36 MHz is close
> enough to 16 MHz that I didn't have to modify the boot loader and uploads
> seem to work ok. Just swap the crystal and go. So, that's one less thing
> to worry about.
>
> Wayne
>
> On Thu, Aug 30, 2018 at 8:04 PM paul swed <***@gmail.com> wrote:
>
>> Wayne very good progress. You can actually feed the loop coild that exists
>> with the cap it should resonate.
>> Thats my plan at least.
>> Regards
>> Paul
>> WB8TSL
>>
>> On Thu, Aug 30, 2018 at 9:44 PM, Wayne Holder <***@gmail.com>
>> wrote:
>>
>> > I've had some luck improving things with my ATTiny85-based WWVB
>> Simulator
>> > design by replacing the crappy, 8 MHz internal oscillator with an 8 MHz
>> > crystal and removing the tweaked timer values I had previously used. In
>> > addition, based on a suggestion from Paul Swed, I tried looping the
>> antenna
>> > wire a few times around the ferrite rod of a WWVB receiver module I
>> > happened to have lying around and this also greatly improved things (see
>> > photo on web page at
>> > https://sites.google.com/site/wayneholder/controlling-time). In fact,
>> > with
>> > the ferrite rod in place, the BALDR clock now syncs even when completely
>> > disconnected from being grounded to the ATTiny85 and the scope.
>> >
>> > I've updated my web page, and the source code at the bottom of the page,
>> > accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS
>> output
>> > is currently disabled in the code. In addition, I've added some
>> additional
>> > info on my web page about how to compile and download the program to an
>> > ATTiny85 using ATTinyCore by Spence Konde.
>> >
>> > I've ordered a 15.36 MHz crystal to try, as that should let the ATTiny85
>> > generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has
>> helped
>> > improve things quite a bit. In addition, I plan to do more tests on
>> > different types of antennas in order to see if I can make things even
>> more
>> > reliable and stable.
>> >
>> > I still plan on reworking the code so it can also run on a 328-based
>> > Arduino board but, currently, the Arduino IDE has no easy way to work
>> with
>> > boards that don't use a standard, 16 MHz crystal, as this frequency is
>> used
>> > by the serial port and, in turn, by the boot loader, so altering it can
>> > break the ability to upload code. This has actually caused some issues
>> for
>> > some of my other projects, so I'm investigating how this issue might be
>> > handled.
>> >
>> > Also, if anyone is interested in trying out other modulation schemes, I
>> can
>> > easily add a compile option t the code that will let it output a binary
>> > low/high modulation signal instead of the PWM signal.
>> >
>> > Wayne
>> >
>> > On Thu, Aug 30, 2018 at 8:53 AM paul swed <***@gmail.com> wrote:
>> >
>> > > Wayne as I work through the chronverter I do know the good phase
>> tracking
>> > > clocks really demand on frequency behavior. As I measured its +/- .6
>> Hz
>> > at
>> > > 60 KHz. I believe the cheapy wall clocks are a bit wider, but not
>> sure as
>> > > they are hard to actually measure. They do use a small tuning fork
>> > crystal
>> > > and from experience these are sharp. When I experimented with them
>> they
>> > > were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals
>> for
>> > > maybe $2.
>> > > With respect to the antenna. My thinking is a loopstick resonated on
>> 60
>> > KHz
>> > > and most likely driving it push pull or single ended. Thats 1
>> transistor
>> > if
>> > > single ended as common collector if I had to guess. The reason is the
>> > > micros put out a fair level of signal so its a case of upping current
>> > into
>> > > the antenna. But it really will be a bit of experimenting.
>> > > I did look at your code and that was so nice it opened up straight
>> into
>> > the
>> > > arduino IDE.
>> > > Regards
>> > > Paul
>> > > WB8TSL
>> > >
>> > > On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <***@gmail.com
>> >
>> > > wrote:
>> > >
>> > > > For anyone trying out my ATTiny85 code, I've done some additional
>> tests
>> > > and
>> > > > find that placement of the antenna near the clock is very finicky
>> and,
>> > so
>> > > > far, the only way to get a reliable decode of the time in the clock
>> is
>> > by
>> > > > using a scope to monitor the demodulated output and then moving the
>> > > antenna
>> > > > around until the demodulated signal lines up cleanly with modulated
>> > > carrier
>> > > > and there are no intra bit glitches. This can take a bit of
>> patience,
>> > so
>> > > > clearly a better solution needs to be found. I've found that any
>> type
>> > of
>> > > > glitch in the demodulated signal seems to prevent the clock chip
>> from
>> > > > decoding the time.
>> > > >
>> > > > It's possible the difficultly with locking onto my simulated WWVB
>> > signal
>> > > > may be partially due to the design of the clock (from my location
>> it's
>> > > > never been able to to lock onto the real WWVB signal), but I have no
>> > > > reference to compare it against so, for now, I have conclude that
>> the
>> > > > PWM-based modulation scheme my code uses may also be suboptimal for
>> > this
>> > > > application. To make testing even more frustrating, the BALDR clock
>> > I'm
>> > > > using will only look for a signal for about 6 minutes before it
>> goes to
>> > > > sleep and I have to then power cycle the clock to get it to listen
>> > again.
>> > > >
>> > > > So, keep this in mind if you're going to try and replicate my
>> results.
>> > > >
>> > > > Wayne
>> > > >
>> > > > On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <
>> ***@gmail.com>
>> > > > wrote:
>> > > >
>> > > > > For those that have asked for my to publish the source code for my
>> > > > > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly
>> > > written
>> > > > > page on my google site at:
>> > > > >
>> > > > > https://sites.google.com/site/wayneholder/controlling-time
>> > > > >
>> > > > > that describes a bit about how the code works, how to compile it
>> > using
>> > > > the
>> > > > > Arduino IDE, how I tested it, some issues I have observed in
>> testing
>> > it
>> > > > > and, at the bottom of the page, a downloadable zip file that
>> contains
>> > > the
>> > > > > complete source code.
>> > > > >
>> > > > > Note: as mentioned at the top of this page, this is currently a
>> work
>> > in
>> > > > > process, so I'm not yet going to link the article to my main
>> website
>> > > > page,
>> > > > > so you'll need to link in this post to find it. Also, as draft,
>> I'm
>> > > > going
>> > > > > to continue to revise the page until I feel the project is
>> complete
>> > > > enough
>> > > > > to publish. That means the source code zip file is going to
>> > > potentially
>> > > > > change from time to time, too.
>> > > > >
>> > > > > Wayne
>> > > > >
>> > > > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <
>> ***@gmail.com
>> > >
>> > > > > wrote:
>> > > > >
>> > > > >> As a follow up, I now have a simple WWVB simulator written in C
>> > that's
>> > > > >> now running an an ATTiny85 using nothing more than the internal,
>> 8
>> > > > >> mHz oscillator and about a 6 inch length of wire connected to
>> one of
>> > > the
>> > > > >> pins as an antenna. It generates an approximate 60 kHz signal
>> using
>> > > > PWM on
>> > > > >> timer 1. I tweaked the timer value a bit to correct for some
>> > variance
>> > > > in
>> > > > >> the internal oscillator, but I' not even sure that was
>> necessary, as
>> > > my
>> > > > >> target is just a BALDR Model B0114ST, consumer grade "Atomic"
>> > clock.
>> > > > >> Modulation is done by varying the duty cycle of the PWM to
>> > approximate
>> > > > the
>> > > > >> -17 dBr drop on the carrier. But, again, I don't think this
>> value
>> > is
>> > > > >> critical with a consumer clock chip. I tapped the demodulated
>> > output
>> > > > >> inside the clock and displayed it on my scope along with the
>> > generated
>> > > > >> signal and I got good, steady demodulation with the wire antenna
>> > just
>> > > > >> placed near clock. The next step is to connect up a GPS module
>> and
>> > > add
>> > > > >> code to use it to set the time. I'm also going to change the
>> code
>> > to
>> > > > use
>> > > > >> the PPS signal from the GPS to drive the output timing rather
>> than
>> > the
>> > > > test
>> > > > >> code I have now that uses timer 0 to generate the PPS interrupt.
>> > I'm
>> > > > happy
>> > > > >> to share details if anyone is interested.
>> > > > >>
>> > > > >> Wayne
>> > > > >>
>> > > > >>
>> > > > >>
>> > > > >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com>
>> > > wrote:
>> > > > >>
>> > > > >>> That would be a great neighbor to have but I can tell you around
>> > here
>> > > > its
>> > > > >>> the phone. Not to concerned about someone putting up a wwvb
>> > > > replacement.
>> > > > >>> And I can always up the power. Chickle.
>> > > > >>> Regards
>> > > > >>> Paul
>> > > > >>>
>> > > > >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org>
>> wrote:
>> > > > >>>
>> > > > >>> > Hi
>> > > > >>> >
>> > > > >>> > The gotcha is if you have neighbors two or three doors away
>> that
>> > > > *also*
>> > > > >>> > put up one of
>> > > > >>> > these devices. You then have a real problem with the
>> neighbor(s)
>> > in
>> > > > the
>> > > > >>> > middle. The
>> > > > >>> > wavelength is long enough that Raleigh issues won’t get you.
>> You
>> > > > still
>> > > > >>> > have the two
>> > > > >>> > signals ( at slightly different frequencies) beating against
>> each
>> > > > >>> other.
>> > > > >>> > The result is
>> > > > >>> > going to show up as who knows what to this or that receiver.
>> > With a
>> > > > >>> > precision receiver,
>> > > > >>> > you might even have issues from the guy two houses away …...
>> > > > >>> >
>> > > > >>> > Bob
>> > > > >>> >
>> > > > >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com
>> >
>> > > > wrote:
>> > > > >>> > >
>> > > > >>> > > Agree with the conversation. With respect to neighbors when
>> the
>> > > day
>> > > > >>> comes
>> > > > >>> > > they may ask you to boost your signal. :-)
>> > > > >>> > > Granted maybe the day won't come but at least having your
>> local
>> > > > >>> clocks
>> > > > >>> > work
>> > > > >>> > > is nice.
>> > > > >>> > > Regards
>> > > > >>> > > Paul
>> > > > >>> > > WB8TSL
>> > > > >>> > >
>> > > > >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
>> > > > >>> ***@gmail.com>
>> > > > >>> > > wrote:
>> > > > >>> > >
>> > > > >>> > >> With the watch being physically close to the faux WWVB
>> > > > >>> "transmitter",
>> > > > >>> > one
>> > > > >>> > >> is in
>> > > > >>> > >> the so-called "near field" regime, where the field strength
>> > > (V/m)
>> > > > >>> falls
>> > > > >>> > as
>> > > > >>> > >> the inverse
>> > > > >>> > >> cube of the distance. If one is putting the watch, say,
>> > within
>> > > a
>> > > > >>> few
>> > > > >>> > >> inches of the
>> > > > >>> > >> transmitter, reliable reception should be available yet the
>> > > signal
>> > > > >>> > should
>> > > > >>> > >> be literally
>> > > > >>> > >> undetectable by any practical receiving device more than a
>> few
>> > > > feet
>> > > > >>> > away.
>> > > > >>> > >> Hence,
>> > > > >>> > >> meeting the FCC field strength limit should be trivial.if
>> the
>> > > > >>> device is
>> > > > >>> > >> used as pictured.
>> > > > >>> > >> However, if one cranks up the power enough to reliably
>> cover
>> > > one's
>> > > > >>> > entire
>> > > > >>> > >> house,
>> > > > >>> > >> then there might be a problem depending how close the
>> nearest
>> > > > >>> neighbor
>> > > > >>> > >> lives,
>> > > > >>> > >> even at levels well within the FCC limit he quotes.
>> > > > >>> > >>
>> > > > >>> > >> Taking the near field relationship in hand, 40 uV/m at 300m
>> > > would
>> > > > >>> > translate
>> > > > >>> > >> into
>> > > > >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough
>> to
>> > > feed
>> > > > >>> most
>> > > > >>> > >> peoples'
>> > > > >>> > >> entire house. So the pragmatic issue would again be-
>> > neighbors.
>> > > > >>> On the
>> > > > >>> > >> other
>> > > > >>> > >> hand, most of them would never be aware of the local
>> signal as
>> > > > long
>> > > > >>> as
>> > > > >>> > they
>> > > > >>> > >> get good
>> > > > >>> > >> time settings, unless they live close enough to Ft. Collins
>> > for
>> > > > the
>> > > > >>> two
>> > > > >>> > >> signals to
>> > > > >>> > >> contend with each other.
>> > > > >>> > >>
>> > > > >>> > >> It looks to me like the ferrite rod antenna is considerable
>> > > > >>> overkill.
>> > > > >>> > Even
>> > > > >>> > >> with no
>> > > > >>> > >> purposeful antenna I'd expect leakage to yield sufficient
>> > signal
>> > > > >>> for at
>> > > > >>> > >> least a few
>> > > > >>> > >> inches.
>> > > > >>> > >>
>> > > > >>> > >> Dana
>> > > > >>> > >>
>> > > > >>> > >>
>> > > > >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
>> > > > >>> ***@gmail.com>
>> > > > >>> > >> wrote:
>> > > > >>> > >>
>> > > > >>> > >>> This guy has what looks like a well thought out design
>> using
>> > a
>> > > > >>> > Sirf-Based
>> > > > >>> > >>> GPS and ATTiny44A chip to generate a signal to update his
>> > > watch:
>> > > > >>> > >>>
>> > > > >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
>> > > > >>> > >>>
>> > > > >>> > >>> Unfortunately, he doesn't seem to have published a
>> schematic
>> > or
>> > > > his
>> > > > >>> > >> source
>> > > > >>> > >>> code. But, he covers enough detail that I think it
>> wouldn't
>> > be
>> > > > too
>> > > > >>> > hard
>> > > > >>> > >> to
>> > > > >>> > >>> replicate what he's done. Or, perhaps he would disclose
>> > these
>> > > > >>> details
>> > > > >>> > if
>> > > > >>> > >>> contacted.
>> > > > >>> > >>>
>> > > > >>> > >>> Wayne
>> > > > >>> > >>>
>> > > > >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
>> > > > ***@pacbell.net>
>> > > > >>> > >> wrote:
>> > > > >>> > >>>
>> > > > >>> > >>>> I thought I would search in a different way for a WWVB
>> > signal
>> > > > >>> > generator
>> > > > >>> > >>>> design. I found this item. While the designer explains
>> it
>> > > > isn't
>> > > > >>> as
>> > > > >>> > >>>> accurate as WWVB it may be another starting point.
>> > > > >>> > >>>>
>> > > > >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
>> > > > >>> > signal-generator.htm
>> > > > >>> > >>>>
>> > > > >>> > >>>>
>> > > > >>> > >>>>
>> > > > >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
>> > > > >>> > >>>> http://hammondorganservice.com
>> > > > >>> > >>>> Hammond USA warranty service
>> > > > >>> > >>>> "Most people don't have a sense of humor. They think they
>> > do,
>> > > > but
>> > > > >>> they
>> > > > >>> > >>>> don't." --Jonathan Winters
>> > > > >>> > >>>>
>> > > > >>> > >>>> _______________________________________________
>> > > > >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
>> > > > >>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
>> > > > >>> > >>>> listinfo/time-nuts_lists.febo.com
>> > > > >>> > >>>> and follow the instructions there.
>> > > > >>> > >>>>
>> > > > >>> > >>> _______________________________________________
>> > > > >>> > >>> time-nuts mailing list -- time-***@lists.febo.com
>> > > > >>> > >>> To unsubscribe, go to
>> > > > >>> > >>>
>> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> > > > >>> > >>> and follow the instructions there.
>> > > > >>> > >>>
>> > > > >>> > >> _______________________________________________
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>> > > > >>> > _______________________________________________
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Andy Backus
2018-09-05 16:38:29 UTC
Permalink
I have taken a similar approach to Wayne's.


When WWVB blinks off my plan is to have a single GPS receiver in the house with a good antenna and to distribute from it a digital signal that will key little 60 kHz units for each clock.


Attached is source code (well commented) for an Adafruit GPS module and Arduino processor to do that.


The protocol for bits 57 and 58 is this: 57 goes on 24 hours before DST comes on and 58 goes on at 0000 hrs (GMT) on the day of the change. They both stay on until DST is to go off, then 57 goes off 24 hours before the change and 58 goes off on the day of.


Andy Backus


________________________________
From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Wayne Holder <***@gmail.com>
Sent: Wednesday, September 5, 2018 3:01 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Signal Generator

I've reworked my WWVB Simulator so it can now run on a slightly modified,
328-based Arduino (swapped in a 16.36 MHz crystal for the standard 16 MHz.)
The new code is also now using a GPS module to set the time from the
GPS $GPRMC message and my BALDR clock just syncs up nicely. I used a
GlobalTopGPS module (similar to the one used in this Adafruit GPS module
<https://www.adafruit.com/product/746>) but, with minor changes, it should

work with any GPS module. The main change needed is configuring the
message used to set the module to only send $GPRMC messages (at a 1 second
interval) and suppress the others NMEA messages.

The last step is to to set the DST status bits (57 and 58) in the WWVB
message, but I'm little bit confused as to when to precisely set these
bits. For reference, the the Java code (below) that I used to prototype
and test the algorithms before converting to C. The code computes the
starting day of year and ending day of year and the idea is to use these
two DOY values to control to setting bits 57 and 58. But, it's unclear to
me if I should set starting and ending state (code 2 and 1, respectively)
on the Sunday of the change or on the days before and after this date? Or,
are the starting and ending states set on Sunday and the other states on
the following Mondays? I'm confused.

Wayne

public class DaylightSavings {
private static final int daysToMonth[][] = {
{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 },
{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 },
};
private static final int MARCH = 3;
private static final int NOVEMBER = 11;

/*
* Compute state and end of Daylight Savings time for specified 4 digit year
* DST Starts the 2nd Sunday of March at 2:00 AM
* DST Ends the first Sunday of November at 1:00 AM
*/

public static void main (String[] args) {
int year = 2018;
int start = getNthSundayOfMonth(2, MARCH, year); //
Get 2nd Sunday of March
int end = getNthSundayOfMonth(1, NOVEMBER, year); //
Get 1st Sunday of November
int startDoy = getDayOfYear(start, MARCH, isLeapYear(year));
int endDoy = getDayOfYear(end, NOVEMBER, isLeapYear(year));
System.out.println("DST starts: " + MARCH + "/" + start + "/" +
year + " (Day of Year: " + startDoy + ") ");
System.out.println("DST ends: " + NOVEMBER + "/" + end + "/" +
year + " (Day of Year: " + endDoy + ")");
}

private static int getNthSundayOfMonth (int sundays, int month, int year) {
for (int day = 1; day < 15; day++) {
if (getDayOfWeek(month, day, year) == 2) {
if (--sundays == 0) {
return day;
}
}
}
// Should never get here
return 0;
}

private static int getDayOfYear (int day, int month, boolean leapYear) {
return daysToMonth[leapYear ? 1 : 0][month - 1] + day;
}

private static boolean isLeapYear (int year) {
return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
}

/**
* Compute Day Of Week (1-7) using Zeller's Method
* @param month (1-12)
* @param day (1-n)
* @param year 4 digit year
* @return day of week (1 = Sat, 2 = Su, 3 = Mon, 4 = Tue, 5 = Wed,
6 = Thr, 7 = Fri
*/
private static int getDayOfWeek ( int month, int day, int year) {
int cen = year / 100;
year = year % 100;
if (month == 1) {
month = 13;
year--;
} else if (month == 2) {
month = 14;
year--;
}
return (day + 13 * (month + 1) / 5 + year + year / 4 + cen / 4 + 5
* cen) % 7 + 1;
}
}


On Sat, Sep 1, 2018 at 5:14 PM Wayne Holder <***@gmail.com> wrote:

> My 15.36 MHz crystals arrived and using one to replace the 8 MHz crystal
> seems to, again, improve the ability of the BALDR clock to lock onto and
> decode the signal. It now reliably syncs if the clock is within 6-7 inches
> of the tuned, ferrite rod antenna (still just wrapping the wire around the
> rod.) With just a loose, wire antenna, the clock syncs if the antenna is
> with 2-3 inches of the clock, which is also an improvement.
>
> I'm also starting to work on moving the code over to an Arduino using an
> old Duemilanove board I had lying around, as ithe crystal it uses is a
> standard, HC-49 package, which makes it easer to replace than the surface
> mount crystals used on modern Arduino boards (you can also get a cheap clone
> of the Duemilanove on eBay
> <https://www.ebay.com/itm/Duemilanove-USB-Board-2009-ATMega328P-PU-Microcontroller-Compatible-With-Arduino/182256700970> for
> about $6 + shipping.) And, as near as I can tell, 15.36 MHz is close
> enough to 16 MHz that I didn't have to modify the boot loader and uploads
> seem to work ok. Just swap the crystal and go. So, that's one less thing
> to worry about.
>
> Wayne
>
> On Thu, Aug 30, 2018 at 8:04 PM paul swed <***@gmail.com> wrote:
>
>> Wayne very good progress. You can actually feed the loop coild that exists
>> with the cap it should resonate.
>> Thats my plan at least.
>> Regards
>> Paul
>> WB8TSL
>>
>> On Thu, Aug 30, 2018 at 9:44 PM, Wayne Holder <***@gmail.com>
>> wrote:
>>
>> > I've had some luck improving things with my ATTiny85-based WWVB
>> Simulator
>> > design by replacing the crappy, 8 MHz internal oscillator with an 8 MHz
>> > crystal and removing the tweaked timer values I had previously used. In
>> > addition, based on a suggestion from Paul Swed, I tried looping the
>> antenna
>> > wire a few times around the ferrite rod of a WWVB receiver module I
>> > happened to have lying around and this also greatly improved things (see
>> > photo on web page at
>> > https://sites.google.com/site/wayneholder/controlling-time). In fact,
>> > with
>> > the ferrite rod in place, the BALDR clock now syncs even when completely
>> > disconnected from being grounded to the ATTiny85 and the scope.
>> >
>> > I've updated my web page, and the source code at the bottom of the page,
>> > accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS
>> output
>> > is currently disabled in the code. In addition, I've added some
>> additional
>> > info on my web page about how to compile and download the program to an
>> > ATTiny85 using ATTinyCore by Spence Konde.
>> >
>> > I've ordered a 15.36 MHz crystal to try, as that should let the ATTiny85
>> > generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has
>> helped
>> > improve things quite a bit. In addition, I plan to do more tests on
>> > different types of antennas in order to see if I can make things even
>> more
>> > reliable and stable.
>> >
>> > I still plan on reworking the code so it can also run on a 328-based
>> > Arduino board but, currently, the Arduino IDE has no easy way to work
>> with
>> > boards that don't use a standard, 16 MHz crystal, as this frequency is
>> used
>> > by the serial port and, in turn, by the boot loader, so altering it can
>> > break the ability to upload code. This has actually caused some issues
>> for
>> > some of my other projects, so I'm investigating how this issue might be
>> > handled.
>> >
>> > Also, if anyone is interested in trying out other modulation schemes, I
>> can
>> > easily add a compile option t the code that will let it output a binary
>> > low/high modulation signal instead of the PWM signal.
>> >
>> > Wayne
>> >
>> > On Thu, Aug 30, 2018 at 8:53 AM paul swed <***@gmail.com> wrote:
>> >
>> > > Wayne as I work through the chronverter I do know the good phase
>> tracking
>> > > clocks really demand on frequency behavior. As I measured its +/- .6
>> Hz
>> > at
>> > > 60 KHz. I believe the cheapy wall clocks are a bit wider, but not
>> sure as
>> > > they are hard to actually measure. They do use a small tuning fork
>> > crystal
>> > > and from experience these are sharp. When I experimented with them
>> they
>> > > were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals
>> for
>> > > maybe $2.
>> > > With respect to the antenna. My thinking is a loopstick resonated on
>> 60
>> > KHz
>> > > and most likely driving it push pull or single ended. Thats 1
>> transistor
>> > if
>> > > single ended as common collector if I had to guess. The reason is the
>> > > micros put out a fair level of signal so its a case of upping current
>> > into
>> > > the antenna. But it really will be a bit of experimenting.
>> > > I did look at your code and that was so nice it opened up straight
>> into
>> > the
>> > > arduino IDE.
>> > > Regards
>> > > Paul
>> > > WB8TSL
>> > >
>> > > On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <***@gmail.com
>> >
>> > > wrote:
>> > >
>> > > > For anyone trying out my ATTiny85 code, I've done some additional
>> tests
>> > > and
>> > > > find that placement of the antenna near the clock is very finicky
>> and,
>> > so
>> > > > far, the only way to get a reliable decode of the time in the clock
>> is
>> > by
>> > > > using a scope to monitor the demodulated output and then moving the
>> > > antenna
>> > > > around until the demodulated signal lines up cleanly with modulated
>> > > carrier
>> > > > and there are no intra bit glitches. This can take a bit of
>> patience,
>> > so
>> > > > clearly a better solution needs to be found. I've found that any
>> type
>> > of
>> > > > glitch in the demodulated signal seems to prevent the clock chip
>> from
>> > > > decoding the time.
>> > > >
>> > > > It's possible the difficultly with locking onto my simulated WWVB
>> > signal
>> > > > may be partially due to the design of the clock (from my location
>> it's
>> > > > never been able to to lock onto the real WWVB signal), but I have no
>> > > > reference to compare it against so, for now, I have conclude that
>> the
>> > > > PWM-based modulation scheme my code uses may also be suboptimal for
>> > this
>> > > > application. To make testing even more frustrating, the BALDR clock
>> > I'm
>> > > > using will only look for a signal for about 6 minutes before it
>> goes to
>> > > > sleep and I have to then power cycle the clock to get it to listen
>> > again.
>> > > >
>> > > > So, keep this in mind if you're going to try and replicate my
>> results.
>> > > >
>> > > > Wayne
>> > > >
>> > > > On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <
>> ***@gmail.com>
>> > > > wrote:
>> > > >
>> > > > > For those that have asked for my to publish the source code for my
>> > > > > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly
>> > > written
>> > > > > page on my google site at:
>> > > > >
>> > > > > https://sites.google.com/site/wayneholder/controlling-time
>> > > > >
>> > > > > that describes a bit about how the code works, how to compile it
>> > using
>> > > > the
>> > > > > Arduino IDE, how I tested it, some issues I have observed in
>> testing
>> > it
>> > > > > and, at the bottom of the page, a downloadable zip file that
>> contains
>> > > the
>> > > > > complete source code.
>> > > > >
>> > > > > Note: as mentioned at the top of this page, this is currently a
>> work
>> > in
>> > > > > process, so I'm not yet going to link the article to my main
>> website
>> > > > page,
>> > > > > so you'll need to link in this post to find it. Also, as draft,
>> I'm
>> > > > going
>> > > > > to continue to revise the page until I feel the project is
>> complete
>> > > > enough
>> > > > > to publish. That means the source code zip file is going to
>> > > potentially
>> > > > > change from time to time, too.
>> > > > >
>> > > > > Wayne
>> > > > >
>> > > > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <
>> ***@gmail.com
>> > >
>> > > > > wrote:
>> > > > >
>> > > > >> As a follow up, I now have a simple WWVB simulator written in C
>> > that's
>> > > > >> now running an an ATTiny85 using nothing more than the internal,
>> 8
>> > > > >> mHz oscillator and about a 6 inch length of wire connected to
>> one of
>> > > the
>> > > > >> pins as an antenna. It generates an approximate 60 kHz signal
>> using
>> > > > PWM on
>> > > > >> timer 1. I tweaked the timer value a bit to correct for some
>> > variance
>> > > > in
>> > > > >> the internal oscillator, but I' not even sure that was
>> necessary, as
>> > > my
>> > > > >> target is just a BALDR Model B0114ST, consumer grade "Atomic"
>> > clock.
>> > > > >> Modulation is done by varying the duty cycle of the PWM to
>> > approximate
>> > > > the
>> > > > >> -17 dBr drop on the carrier. But, again, I don't think this
>> value
>> > is
>> > > > >> critical with a consumer clock chip. I tapped the demodulated
>> > output
>> > > > >> inside the clock and displayed it on my scope along with the
>> > generated
>> > > > >> signal and I got good, steady demodulation with the wire antenna
>> > just
>> > > > >> placed near clock. The next step is to connect up a GPS module
>> and
>> > > add
>> > > > >> code to use it to set the time. I'm also going to change the
>> code
>> > to
>> > > > use
>> > > > >> the PPS signal from the GPS to drive the output timing rather
>> than
>> > the
>> > > > test
>> > > > >> code I have now that uses timer 0 to generate the PPS interrupt.
>> > I'm
>> > > > happy
>> > > > >> to share details if anyone is interested.
>> > > > >>
>> > > > >> Wayne
>> > > > >>
>> > > > >>
>> > > > >>
>> > > > >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <***@gmail.com>
>> > > wrote:
>> > > > >>
>> > > > >>> That would be a great neighbor to have but I can tell you around
>> > here
>> > > > its
>> > > > >>> the phone. Not to concerned about someone putting up a wwvb
>> > > > replacement.
>> > > > >>> And I can always up the power. Chickle.
>> > > > >>> Regards
>> > > > >>> Paul
>> > > > >>>
>> > > > >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org>
>> wrote:
>> > > > >>>
>> > > > >>> > Hi
>> > > > >>> >
>> > > > >>> > The gotcha is if you have neighbors two or three doors away
>> that
>> > > > *also*
>> > > > >>> > put up one of
>> > > > >>> > these devices. You then have a real problem with the
>> neighbor(s)
>> > in
>> > > > the
>> > > > >>> > middle. The
>> > > > >>> > wavelength is long enough that Raleigh issues won’t get you.
>> You
>> > > > still
>> > > > >>> > have the two
>> > > > >>> > signals ( at slightly different frequencies) beating against
>> each
>> > > > >>> other.
>> > > > >>> > The result is
>> > > > >>> > going to show up as who knows what to this or that receiver.
>> > With a
>> > > > >>> > precision receiver,
>> > > > >>> > you might even have issues from the guy two houses away …...
>> > > > >>> >
>> > > > >>> > Bob
>> > > > >>> >
>> > > > >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <***@gmail.com
>> >
>> > > > wrote:
>> > > > >>> > >
>> > > > >>> > > Agree with the conversation. With respect to neighbors when
>> the
>> > > day
>> > > > >>> comes
>> > > > >>> > > they may ask you to boost your signal. :-)
>> > > > >>> > > Granted maybe the day won't come but at least having your
>> local
>> > > > >>> clocks
>> > > > >>> > work
>> > > > >>> > > is nice.
>> > > > >>> > > Regards
>> > > > >>> > > Paul
>> > > > >>> > > WB8TSL
>> > > > >>> > >
>> > > > >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
>> > > > >>> ***@gmail.com>
>> > > > >>> > > wrote:
>> > > > >>> > >
>> > > > >>> > >> With the watch being physically close to the faux WWVB
>> > > > >>> "transmitter",
>> > > > >>> > one
>> > > > >>> > >> is in
>> > > > >>> > >> the so-called "near field" regime, where the field strength
>> > > (V/m)
>> > > > >>> falls
>> > > > >>> > as
>> > > > >>> > >> the inverse
>> > > > >>> > >> cube of the distance. If one is putting the watch, say,
>> > within
>> > > a
>> > > > >>> few
>> > > > >>> > >> inches of the
>> > > > >>> > >> transmitter, reliable reception should be available yet the
>> > > signal
>> > > > >>> > should
>> > > > >>> > >> be literally
>> > > > >>> > >> undetectable by any practical receiving device more than a
>> few
>> > > > feet
>> > > > >>> > away.
>> > > > >>> > >> Hence,
>> > > > >>> > >> meeting the FCC field strength limit should be trivial.if
>> the
>> > > > >>> device is
>> > > > >>> > >> used as pictured.
>> > > > >>> > >> However, if one cranks up the power enough to reliably
>> cover
>> > > one's
>> > > > >>> > entire
>> > > > >>> > >> house,
>> > > > >>> > >> then there might be a problem depending how close the
>> nearest
>> > > > >>> neighbor
>> > > > >>> > >> lives,
>> > > > >>> > >> even at levels well within the FCC limit he quotes.
>> > > > >>> > >>
>> > > > >>> > >> Taking the near field relationship in hand, 40 uV/m at 300m
>> > > would
>> > > > >>> > translate
>> > > > >>> > >> into
>> > > > >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough
>> to
>> > > feed
>> > > > >>> most
>> > > > >>> > >> peoples'
>> > > > >>> > >> entire house. So the pragmatic issue would again be-
>> > neighbors.
>> > > > >>> On the
>> > > > >>> > >> other
>> > > > >>> > >> hand, most of them would never be aware of the local
>> signal as
>> > > > long
>> > > > >>> as
>> > > > >>> > they
>> > > > >>> > >> get good
>> > > > >>> > >> time settings, unless they live close enough to Ft. Collins
>> > for
>> > > > the
>> > > > >>> two
>> > > > >>> > >> signals to
>> > > > >>> > >> contend with each other.
>> > > > >>> > >>
>> > > > >>> > >> It looks to me like the ferrite rod antenna is considerable
>> > > > >>> overkill.
>> > > > >>> > Even
>> > > > >>> > >> with no
>> > > > >>> > >> purposeful antenna I'd expect leakage to yield sufficient
>> > signal
>> > > > >>> for at
>> > > > >>> > >> least a few
>> > > > >>> > >> inches.
>> > > > >>> > >>
>> > > > >>> > >> Dana
>> > > > >>> > >>
>> > > > >>> > >>
>> > > > >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
>> > > > >>> ***@gmail.com>
>> > > > >>> > >> wrote:
>> > > > >>> > >>
>> > > > >>> > >>> This guy has what looks like a well thought out design
>> using
>> > a
>> > > > >>> > Sirf-Based
>> > > > >>> > >>> GPS and ATTiny44A chip to generate a signal to update his
>> > > watch:
>> > > > >>> > >>>
>> > > > >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
>> > > > >>> > >>>
>> > > > >>> > >>> Unfortunately, he doesn't seem to have published a
>> schematic
>> > or
>> > > > his
>> > > > >>> > >> source
>> > > > >>> > >>> code. But, he covers enough detail that I think it
>> wouldn't
>> > be
>> > > > too
>> > > > >>> > hard
>> > > > >>> > >> to
>> > > > >>> > >>> replicate what he's done. Or, perhaps he would disclose
>> > these
>> > > > >>> details
>> > > > >>> > if
>> > > > >>> > >>> contacted.
>> > > > >>> > >>>
>> > > > >>> > >>> Wayne
>> > > > >>> > >>>
>> > > > >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
>> > > > ***@pacbell.net>
>> > > > >>> > >> wrote:
>> > > > >>> > >>>
>> > > > >>> > >>>> I thought I would search in a different way for a WWVB
>> > signal
>> > > > >>> > generator
>> > > > >>> > >>>> design. I found this item. While the designer explains
>> it
>> > > > isn't
>> > > > >>> as
>> > > > >>> > >>>> accurate as WWVB it may be another starting point.
>> > > > >>> > >>>>
>> > > > >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
>> > > > >>> > signal-generator.htm
>> > > > >>> > >>>>
>> > > > >>> > >>>>
>> > > > >>> > >>>>
>> > > > >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
>> > > > >>> > >>>> http://hammondorganservice.com
>> > > > >>> > >>>> Hammond USA warranty service
>> > > > >>> > >>>> "Most people don't have a sense of humor. They think they
>> > do,
>> > > > but
>> > > > >>> they
>> > > > >>> > >>>> don't." --Jonathan Winters
>> > > > >>> > >>>>
>> > > > >>> > >>>> _______________________________________________
>> > > > >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
>> > > > >>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
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>> > > > >>> > >>>>
>> > > > >>> > >>> _______________________________________________
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>> > > > >>> > >> _______________________________________________
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Adrian Godwin
2018-09-05 20:02:09 UTC
Permalink
Could you couple the 60kHz signal into the power line ?
It should conveniently pass around most of the house and some ferrite rings
on the incoming mains minimise what goes outside your premises.


On Wed, Sep 5, 2018 at 5:38 PM, Andy Backus <***@msn.com> wrote:

> I have taken a similar approach to Wayne's.
>
>
> When WWVB blinks off my plan is to have a single GPS receiver in the house
> with a good antenna and to distribute from it a digital signal that will
> key little 60 kHz units for each clock.
>
>
> Attached is source code (well commented) for an Adafruit GPS module and
> Arduino processor to do that.
>
>
> The protocol for bits 57 and 58 is this: 57 goes on 24 hours before DST
> comes on and 58 goes on at 0000 hrs (GMT) on the day of the change. They
> both stay on until DST is to go off, then 57 goes off 24 hours before the
> change and 58 goes off on the day of.
>
>
> Andy Backus
>
>
> ________________________________
> From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Wayne
> Holder <***@gmail.com>
> Sent: Wednesday, September 5, 2018 3:01 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] WWVB Signal Generator
>
> I've reworked my WWVB Simulator so it can now run on a slightly modified,
> 328-based Arduino (swapped in a 16.36 MHz crystal for the standard 16 MHz.)
> The new code is also now using a GPS module to set the time from the
> GPS $GPRMC message and my BALDR clock just syncs up nicely. I used a
> GlobalTopGPS module (similar to the one used in this Adafruit GPS module
> <https://www.adafruit.com/product/746>) but, with minor changes, it should
>
> work with any GPS module. The main change needed is configuring the
> message used to set the module to only send $GPRMC messages (at a 1 second
> interval) and suppress the others NMEA messages.
>
> The last step is to to set the DST status bits (57 and 58) in the WWVB
> message, but I'm little bit confused as to when to precisely set these
> bits. For reference, the the Java code (below) that I used to prototype
> and test the algorithms before converting to C. The code computes the
> starting day of year and ending day of year and the idea is to use these
> two DOY values to control to setting bits 57 and 58. But, it's unclear to
> me if I should set starting and ending state (code 2 and 1, respectively)
> on the Sunday of the change or on the days before and after this date? Or,
> are the starting and ending states set on Sunday and the other states on
> the following Mondays? I'm confused.
>
> Wayne
>
> public class DaylightSavings {
> private static final int daysToMonth[][] = {
> { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 },
> { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 },
> };
> private static final int MARCH = 3;
> private static final int NOVEMBER = 11;
>
> /*
> * Compute state and end of Daylight Savings time for specified 4 digit
> year
> * DST Starts the 2nd Sunday of March at 2:00 AM
> * DST Ends the first Sunday of November at 1:00 AM
> */
>
> public static void main (String[] args) {
> int year = 2018;
> int start = getNthSundayOfMonth(2, MARCH, year); //
> Get 2nd Sunday of March
> int end = getNthSundayOfMonth(1, NOVEMBER, year); //
> Get 1st Sunday of November
> int startDoy = getDayOfYear(start, MARCH, isLeapYear(year));
> int endDoy = getDayOfYear(end, NOVEMBER, isLeapYear(year));
> System.out.println("DST starts: " + MARCH + "/" + start + "/" +
> year + " (Day of Year: " + startDoy + ") ");
> System.out.println("DST ends: " + NOVEMBER + "/" + end + "/" +
> year + " (Day of Year: " + endDoy + ")");
> }
>
> private static int getNthSundayOfMonth (int sundays, int month, int
> year) {
> for (int day = 1; day < 15; day++) {
> if (getDayOfWeek(month, day, year) == 2) {
> if (--sundays == 0) {
> return day;
> }
> }
> }
> // Should never get here
> return 0;
> }
>
> private static int getDayOfYear (int day, int month, boolean leapYear) {
> return daysToMonth[leapYear ? 1 : 0][month - 1] + day;
> }
>
> private static boolean isLeapYear (int year) {
> return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
> }
>
> /**
> * Compute Day Of Week (1-7) using Zeller's Method
> * @param month (1-12)
> * @param day (1-n)
> * @param year 4 digit year
> * @return day of week (1 = Sat, 2 = Su, 3 = Mon, 4 = Tue, 5 = Wed,
> 6 = Thr, 7 = Fri
> */
> private static int getDayOfWeek ( int month, int day, int year) {
> int cen = year / 100;
> year = year % 100;
> if (month == 1) {
> month = 13;
> year--;
> } else if (month == 2) {
> month = 14;
> year--;
> }
> return (day + 13 * (month + 1) / 5 + year + year / 4 + cen / 4 + 5
> * cen) % 7 + 1;
> }
> }
>
>
> On Sat, Sep 1, 2018 at 5:14 PM Wayne Holder <***@gmail.com>
> wrote:
>
> > My 15.36 MHz crystals arrived and using one to replace the 8 MHz crystal
> > seems to, again, improve the ability of the BALDR clock to lock onto and
> > decode the signal. It now reliably syncs if the clock is within 6-7
> inches
> > of the tuned, ferrite rod antenna (still just wrapping the wire around
> the
> > rod.) With just a loose, wire antenna, the clock syncs if the antenna is
> > with 2-3 inches of the clock, which is also an improvement.
> >
> > I'm also starting to work on moving the code over to an Arduino using an
> > old Duemilanove board I had lying around, as ithe crystal it uses is a
> > standard, HC-49 package, which makes it easer to replace than the surface
> > mount crystals used on modern Arduino boards (you can also get a cheap
> clone
> > of the Duemilanove on eBay
> > <https://www.ebay.com/itm/Duemilanove-USB-Board-2009-
> ATMega328P-PU-Microcontroller-Compatible-With-Arduino/182256700970> for
> > about $6 + shipping.) And, as near as I can tell, 15.36 MHz is close
> > enough to 16 MHz that I didn't have to modify the boot loader and uploads
> > seem to work ok. Just swap the crystal and go. So, that's one less
> thing
> > to worry about.
> >
> > Wayne
> >
> > On Thu, Aug 30, 2018 at 8:04 PM paul swed <***@gmail.com> wrote:
> >
> >> Wayne very good progress. You can actually feed the loop coild that
> exists
> >> with the cap it should resonate.
> >> Thats my plan at least.
> >> Regards
> >> Paul
> >> WB8TSL
> >>
> >> On Thu, Aug 30, 2018 at 9:44 PM, Wayne Holder <***@gmail.com>
> >> wrote:
> >>
> >> > I've had some luck improving things with my ATTiny85-based WWVB
> >> Simulator
> >> > design by replacing the crappy, 8 MHz internal oscillator with an 8
> MHz
> >> > crystal and removing the tweaked timer values I had previously used.
> In
> >> > addition, based on a suggestion from Paul Swed, I tried looping the
> >> antenna
> >> > wire a few times around the ferrite rod of a WWVB receiver module I
> >> > happened to have lying around and this also greatly improved things
> (see
> >> > photo on web page at
> >> > https://sites.google.com/site/wayneholder/controlling-time). In
> fact,
> >> > with
> >> > the ferrite rod in place, the BALDR clock now syncs even when
> completely
> >> > disconnected from being grounded to the ATTiny85 and the scope.
> >> >
> >> > I've updated my web page, and the source code at the bottom of the
> page,
> >> > accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS
> >> output
> >> > is currently disabled in the code. In addition, I've added some
> >> additional
> >> > info on my web page about how to compile and download the program to
> an
> >> > ATTiny85 using ATTinyCore by Spence Konde.
> >> >
> >> > I've ordered a 15.36 MHz crystal to try, as that should let the
> ATTiny85
> >> > generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has
> >> helped
> >> > improve things quite a bit. In addition, I plan to do more tests on
> >> > different types of antennas in order to see if I can make things even
> >> more
> >> > reliable and stable.
> >> >
> >> > I still plan on reworking the code so it can also run on a 328-based
> >> > Arduino board but, currently, the Arduino IDE has no easy way to work
> >> with
> >> > boards that don't use a standard, 16 MHz crystal, as this frequency is
> >> used
> >> > by the serial port and, in turn, by the boot loader, so altering it
> can
> >> > break the ability to upload code. This has actually caused some
> issues
> >> for
> >> > some of my other projects, so I'm investigating how this issue might
> be
> >> > handled.
> >> >
> >> > Also, if anyone is interested in trying out other modulation schemes,
> I
> >> can
> >> > easily add a compile option t the code that will let it output a
> binary
> >> > low/high modulation signal instead of the PWM signal.
> >> >
> >> > Wayne
> >> >
> >> > On Thu, Aug 30, 2018 at 8:53 AM paul swed <***@gmail.com>
> wrote:
> >> >
> >> > > Wayne as I work through the chronverter I do know the good phase
> >> tracking
> >> > > clocks really demand on frequency behavior. As I measured its +/- .6
> >> Hz
> >> > at
> >> > > 60 KHz. I believe the cheapy wall clocks are a bit wider, but not
> >> sure as
> >> > > they are hard to actually measure. They do use a small tuning fork
> >> > crystal
> >> > > and from experience these are sharp. When I experimented with them
> >> they
> >> > > were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals
> >> for
> >> > > maybe $2.
> >> > > With respect to the antenna. My thinking is a loopstick resonated on
> >> 60
> >> > KHz
> >> > > and most likely driving it push pull or single ended. Thats 1
> >> transistor
> >> > if
> >> > > single ended as common collector if I had to guess. The reason is
> the
> >> > > micros put out a fair level of signal so its a case of upping
> current
> >> > into
> >> > > the antenna. But it really will be a bit of experimenting.
> >> > > I did look at your code and that was so nice it opened up straight
> >> into
> >> > the
> >> > > arduino IDE.
> >> > > Regards
> >> > > Paul
> >> > > WB8TSL
> >> > >
> >> > > On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder <
> ***@gmail.com
> >> >
> >> > > wrote:
> >> > >
> >> > > > For anyone trying out my ATTiny85 code, I've done some additional
> >> tests
> >> > > and
> >> > > > find that placement of the antenna near the clock is very finicky
> >> and,
> >> > so
> >> > > > far, the only way to get a reliable decode of the time in the
> clock
> >> is
> >> > by
> >> > > > using a scope to monitor the demodulated output and then moving
> the
> >> > > antenna
> >> > > > around until the demodulated signal lines up cleanly with
> modulated
> >> > > carrier
> >> > > > and there are no intra bit glitches. This can take a bit of
> >> patience,
> >> > so
> >> > > > clearly a better solution needs to be found. I've found that any
> >> type
> >> > of
> >> > > > glitch in the demodulated signal seems to prevent the clock chip
> >> from
> >> > > > decoding the time.
> >> > > >
> >> > > > It's possible the difficultly with locking onto my simulated WWVB
> >> > signal
> >> > > > may be partially due to the design of the clock (from my location
> >> it's
> >> > > > never been able to to lock onto the real WWVB signal), but I have
> no
> >> > > > reference to compare it against so, for now, I have conclude that
> >> the
> >> > > > PWM-based modulation scheme my code uses may also be suboptimal
> for
> >> > this
> >> > > > application. To make testing even more frustrating, the BALDR
> clock
> >> > I'm
> >> > > > using will only look for a signal for about 6 minutes before it
> >> goes to
> >> > > > sleep and I have to then power cycle the clock to get it to listen
> >> > again.
> >> > > >
> >> > > > So, keep this in mind if you're going to try and replicate my
> >> results.
> >> > > >
> >> > > > Wayne
> >> > > >
> >> > > > On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder <
> >> ***@gmail.com>
> >> > > > wrote:
> >> > > >
> >> > > > > For those that have asked for my to publish the source code for
> my
> >> > > > > ATTiny85-based WWVB simulator, I have put up a somewhat
> hurriedly
> >> > > written
> >> > > > > page on my google site at:
> >> > > > >
> >> > > > > https://sites.google.com/site/wayneholder/controlling-time
> >> > > > >
> >> > > > > that describes a bit about how the code works, how to compile it
> >> > using
> >> > > > the
> >> > > > > Arduino IDE, how I tested it, some issues I have observed in
> >> testing
> >> > it
> >> > > > > and, at the bottom of the page, a downloadable zip file that
> >> contains
> >> > > the
> >> > > > > complete source code.
> >> > > > >
> >> > > > > Note: as mentioned at the top of this page, this is currently a
> >> work
> >> > in
> >> > > > > process, so I'm not yet going to link the article to my main
> >> website
> >> > > > page,
> >> > > > > so you'll need to link in this post to find it. Also, as draft,
> >> I'm
> >> > > > going
> >> > > > > to continue to revise the page until I feel the project is
> >> complete
> >> > > > enough
> >> > > > > to publish. That means the source code zip file is going to
> >> > > potentially
> >> > > > > change from time to time, too.
> >> > > > >
> >> > > > > Wayne
> >> > > > >
> >> > > > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder <
> >> ***@gmail.com
> >> > >
> >> > > > > wrote:
> >> > > > >
> >> > > > >> As a follow up, I now have a simple WWVB simulator written in C
> >> > that's
> >> > > > >> now running an an ATTiny85 using nothing more than the
> internal,
> >> 8
> >> > > > >> mHz oscillator and about a 6 inch length of wire connected to
> >> one of
> >> > > the
> >> > > > >> pins as an antenna. It generates an approximate 60 kHz signal
> >> using
> >> > > > PWM on
> >> > > > >> timer 1. I tweaked the timer value a bit to correct for some
> >> > variance
> >> > > > in
> >> > > > >> the internal oscillator, but I' not even sure that was
> >> necessary, as
> >> > > my
> >> > > > >> target is just a BALDR Model B0114ST, consumer grade "Atomic"
> >> > clock.
> >> > > > >> Modulation is done by varying the duty cycle of the PWM to
> >> > approximate
> >> > > > the
> >> > > > >> -17 dBr drop on the carrier. But, again, I don't think this
> >> value
> >> > is
> >> > > > >> critical with a consumer clock chip. I tapped the demodulated
> >> > output
> >> > > > >> inside the clock and displayed it on my scope along with the
> >> > generated
> >> > > > >> signal and I got good, steady demodulation with the wire
> antenna
> >> > just
> >> > > > >> placed near clock. The next step is to connect up a GPS module
> >> and
> >> > > add
> >> > > > >> code to use it to set the time. I'm also going to change the
> >> code
> >> > to
> >> > > > use
> >> > > > >> the PPS signal from the GPS to drive the output timing rather
> >> than
> >> > the
> >> > > > test
> >> > > > >> code I have now that uses timer 0 to generate the PPS
> interrupt.
> >> > I'm
> >> > > > happy
> >> > > > >> to share details if anyone is interested.
> >> > > > >>
> >> > > > >> Wayne
> >> > > > >>
> >> > > > >>
> >> > > > >>
> >> > > > >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed <
> ***@gmail.com>
> >> > > wrote:
> >> > > > >>
> >> > > > >>> That would be a great neighbor to have but I can tell you
> around
> >> > here
> >> > > > its
> >> > > > >>> the phone. Not to concerned about someone putting up a wwvb
> >> > > > replacement.
> >> > > > >>> And I can always up the power. Chickle.
> >> > > > >>> Regards
> >> > > > >>> Paul
> >> > > > >>>
> >> > > > >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <***@n1k.org>
> >> wrote:
> >> > > > >>>
> >> > > > >>> > Hi
> >> > > > >>> >
> >> > > > >>> > The gotcha is if you have neighbors two or three doors away
> >> that
> >> > > > *also*
> >> > > > >>> > put up one of
> >> > > > >>> > these devices. You then have a real problem with the
> >> neighbor(s)
> >> > in
> >> > > > the
> >> > > > >>> > middle. The
> >> > > > >>> > wavelength is long enough that Raleigh issues won’t get you.
> >> You
> >> > > > still
> >> > > > >>> > have the two
> >> > > > >>> > signals ( at slightly different frequencies) beating against
> >> each
> >> > > > >>> other.
> >> > > > >>> > The result is
> >> > > > >>> > going to show up as who knows what to this or that receiver.
> >> > With a
> >> > > > >>> > precision receiver,
> >> > > > >>> > you might even have issues from the guy two houses away …...
> >> > > > >>> >
> >> > > > >>> > Bob
> >> > > > >>> >
> >> > > > >>> > > On Aug 26, 2018, at 1:08 PM, paul swed <
> ***@gmail.com
> >> >
> >> > > > wrote:
> >> > > > >>> > >
> >> > > > >>> > > Agree with the conversation. With respect to neighbors
> when
> >> the
> >> > > day
> >> > > > >>> comes
> >> > > > >>> > > they may ask you to boost your signal. :-)
> >> > > > >>> > > Granted maybe the day won't come but at least having your
> >> local
> >> > > > >>> clocks
> >> > > > >>> > work
> >> > > > >>> > > is nice.
> >> > > > >>> > > Regards
> >> > > > >>> > > Paul
> >> > > > >>> > > WB8TSL
> >> > > > >>> > >
> >> > > > >>> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow <
> >> > > > >>> ***@gmail.com>
> >> > > > >>> > > wrote:
> >> > > > >>> > >
> >> > > > >>> > >> With the watch being physically close to the faux WWVB
> >> > > > >>> "transmitter",
> >> > > > >>> > one
> >> > > > >>> > >> is in
> >> > > > >>> > >> the so-called "near field" regime, where the field
> strength
> >> > > (V/m)
> >> > > > >>> falls
> >> > > > >>> > as
> >> > > > >>> > >> the inverse
> >> > > > >>> > >> cube of the distance. If one is putting the watch, say,
> >> > within
> >> > > a
> >> > > > >>> few
> >> > > > >>> > >> inches of the
> >> > > > >>> > >> transmitter, reliable reception should be available yet
> the
> >> > > signal
> >> > > > >>> > should
> >> > > > >>> > >> be literally
> >> > > > >>> > >> undetectable by any practical receiving device more than
> a
> >> few
> >> > > > feet
> >> > > > >>> > away.
> >> > > > >>> > >> Hence,
> >> > > > >>> > >> meeting the FCC field strength limit should be trivial.if
> >> the
> >> > > > >>> device is
> >> > > > >>> > >> used as pictured.
> >> > > > >>> > >> However, if one cranks up the power enough to reliably
> >> cover
> >> > > one's
> >> > > > >>> > entire
> >> > > > >>> > >> house,
> >> > > > >>> > >> then there might be a problem depending how close the
> >> nearest
> >> > > > >>> neighbor
> >> > > > >>> > >> lives,
> >> > > > >>> > >> even at levels well within the FCC limit he quotes.
> >> > > > >>> > >>
> >> > > > >>> > >> Taking the near field relationship in hand, 40 uV/m at
> 300m
> >> > > would
> >> > > > >>> > translate
> >> > > > >>> > >> into
> >> > > > >>> > >> a whopping 0.135 V/m at 20 meters range, more than enough
> >> to
> >> > > feed
> >> > > > >>> most
> >> > > > >>> > >> peoples'
> >> > > > >>> > >> entire house. So the pragmatic issue would again be-
> >> > neighbors.
> >> > > > >>> On the
> >> > > > >>> > >> other
> >> > > > >>> > >> hand, most of them would never be aware of the local
> >> signal as
> >> > > > long
> >> > > > >>> as
> >> > > > >>> > they
> >> > > > >>> > >> get good
> >> > > > >>> > >> time settings, unless they live close enough to Ft.
> Collins
> >> > for
> >> > > > the
> >> > > > >>> two
> >> > > > >>> > >> signals to
> >> > > > >>> > >> contend with each other.
> >> > > > >>> > >>
> >> > > > >>> > >> It looks to me like the ferrite rod antenna is
> considerable
> >> > > > >>> overkill.
> >> > > > >>> > Even
> >> > > > >>> > >> with no
> >> > > > >>> > >> purposeful antenna I'd expect leakage to yield sufficient
> >> > signal
> >> > > > >>> for at
> >> > > > >>> > >> least a few
> >> > > > >>> > >> inches.
> >> > > > >>> > >>
> >> > > > >>> > >> Dana
> >> > > > >>> > >>
> >> > > > >>> > >>
> >> > > > >>> > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder <
> >> > > > >>> ***@gmail.com>
> >> > > > >>> > >> wrote:
> >> > > > >>> > >>
> >> > > > >>> > >>> This guy has what looks like a well thought out design
> >> using
> >> > a
> >> > > > >>> > Sirf-Based
> >> > > > >>> > >>> GPS and ATTiny44A chip to generate a signal to update
> his
> >> > > watch:
> >> > > > >>> > >>>
> >> > > > >>> > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/
> >> > > > >>> > >>>
> >> > > > >>> > >>> Unfortunately, he doesn't seem to have published a
> >> schematic
> >> > or
> >> > > > his
> >> > > > >>> > >> source
> >> > > > >>> > >>> code. But, he covers enough detail that I think it
> >> wouldn't
> >> > be
> >> > > > too
> >> > > > >>> > hard
> >> > > > >>> > >> to
> >> > > > >>> > >>> replicate what he's done. Or, perhaps he would disclose
> >> > these
> >> > > > >>> details
> >> > > > >>> > if
> >> > > > >>> > >>> contacted.
> >> > > > >>> > >>>
> >> > > > >>> > >>> Wayne
> >> > > > >>> > >>>
> >> > > > >>> > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <
> >> > > > ***@pacbell.net>
> >> > > > >>> > >> wrote:
> >> > > > >>> > >>>
> >> > > > >>> > >>>> I thought I would search in a different way for a WWVB
> >> > signal
> >> > > > >>> > generator
> >> > > > >>> > >>>> design. I found this item. While the designer
> explains
> >> it
> >> > > > isn't
> >> > > > >>> as
> >> > > > >>> > >>>> accurate as WWVB it may be another starting point.
> >> > > > >>> > >>>>
> >> > > > >>> > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time-
> >> > > > >>> > signal-generator.htm
> >> > > > >>> > >>>>
> >> > > > >>> > >>>>
> >> > > > >>> > >>>>
> >> > > > >>> > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> >> > > > >>> > >>>> http://hammondorganservice.com
> >> > > > >>> > >>>> Hammond USA warranty service
> >> > > > >>> > >>>> "Most people don't have a sense of humor. They think
> they
> >> > do,
> >> > > > but
> >> > > > >>> they
> >> > > > >>> > >>>> don't." --Jonathan Winters
> >> > > > >>> > >>>>
> >> > > > >>> > >>>> _______________________________________________
> >> > > > >>> > >>>> time-nuts mailing list -- time-***@lists.febo.com
> >> > > > >>> > >>>> To unsubscribe, go to http://lists.febo.com/mailman/
> >> > > > >>> > >>>> listinfo/time-nuts_lists.febo.com
> >> > > > >>> > >>>> and follow the instructions there.
> >> > > > >>> > >>>>
> >> > > > >>> > >>> _______________________________________________
> >> > > > >>> > >>> time-nuts mailing list -- time-***@lists.febo.com
> >> > > > >>> > >>> To unsubscribe, go to
> >> > > > >>> > >>>
> >> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> >> > > > >>> > >>> and follow the instructions there.
> >> > > > >>> > >>>
> >> > > > >>> > >> _______________________________________________
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> >> > > > >>> > >>
> >> > > > >>> > > _______________________________________________
> >> > > > >>> > > time-nuts mailing list -- time-***@lists.febo.com
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> >> > > > >>> >
> >> > > > >>> >
> >> > > > >>> > _______________________________________________
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> >> > > > >>
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ew via time-nuts
2018-08-27 12:08:04 UTC
Permalink
 
In the August NED New Equipment Digest NEWEQUIPMENT.com issue on page 30 and 31 is an infomercial on the 10K Clock, is covered with some nice pictures.
Bert Kehren
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Mark Sims
2018-09-05 15:47:07 UTC
Permalink
If your receiver has it the $GPZDA can be a better message to use. They usually have better seconds resolution and some receivers give them some special love as to when they come out. But, depending upon your code, this may not matter. Also check to see if your chosen time message comes out before or after the 1PPS.


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Wayne Holder
2018-09-06 00:49:09 UTC
Permalink
I was able to sort out my issue with the DST bits with the help of the
code Andy Backus recently published. I believe my code should now be ready
for anyone who's curious to try out. Complete details are available on the
following page:

https://sites.google.com/site/wayneholder/controlling-time-2

This new code is a bit simpler than the ATTiny85-based code I published
before, as I've eliminated the use of interrupts and now use the GPS
module's PPS signal to control bit timing and simple calls to the millis()
function to control the timing of the bit modulation. I still recommend
swapping the 16 MHz crystal for a 15.36 MHz one, but you should be able to
run the code on any ATMega328-based Arduino using a 16 MHz clock, although
with reduced range from the antenna to the clock.

Wayne

On Wed, Sep 5, 2018 at 8:48 AM Mark Sims <***@hotmail.com> wrote:

> If your receiver has it the $GPZDA can be a better message to use. They
> usually have better seconds resolution and some receivers give them some
> special love as to when they come out. But, depending upon your code, this
> may not matter. Also check to see if your chosen time message comes out
> before or after the 1PPS.
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Andy Backus
2018-09-06 17:17:34 UTC
Permalink
Instead of relying on the PPS to time the start of the simulated WWVB transmissions, I opted instead to rely on the Arduino timing functions and then refresh the data and the start every five minutes. No WWVB clocks use the signal continuously; generally they all copy the signal once a day.


Also -- when the GlobalTop loses a fix it still puts out the RMC sentence, just without the lat and lon data. And the PPS immediately stops. I designed the parsing scheme to account for that. How long that reporting would continue I don't know.


Andy Backus


________________________________
From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Wayne Holder <***@gmail.com>
Sent: Wednesday, September 5, 2018 5:49 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Signal Generator

I was able to sort out my issue with the DST bits with the help of the
code Andy Backus recently published. I believe my code should now be ready
for anyone who's curious to try out. Complete details are available on the
following page:

https://sites.google.com/site/wayneholder/controlling-time-2


This new code is a bit simpler than the ATTiny85-based code I published
before, as I've eliminated the use of interrupts and now use the GPS
module's PPS signal to control bit timing and simple calls to the millis()
function to control the timing of the bit modulation. I still recommend
swapping the 16 MHz crystal for a 15.36 MHz one, but you should be able to
run the code on any ATMega328-based Arduino using a 16 MHz clock, although
with reduced range from the antenna to the clock.

Wayne

On Wed, Sep 5, 2018 at 8:48 AM Mark Sims <***@hotmail.com> wrote:

> If your receiver has it the $GPZDA can be a better message to use. They
> usually have better seconds resolution and some receivers give them some
> special love as to when they come out. But, depending upon your code, this
> may not matter. Also check to see if your chosen time message comes out
> before or after the 1PPS.
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Hal Murray
2018-09-07 06:24:16 UTC
Permalink
***@msn.com said:
> Also -- when the GlobalTop loses a fix it still puts out the RMC sentence,
> just without the lat and lon data. And the PPS immediately stops. I
> designed the parsing scheme to account for that. How long that reporting
> would continue I don't know.

The RMC sentence has a valid field with an A or V.

Some GPS receivers don't stop the PPS when not working. I expect some of them
continue with dead-reconing values for lat/lon.


--
These are my opinions. I hate spam.




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