[time-nuts] tcxo

[Jim Harman]

Some of the Arduinos (not sure about Mini 04 but I am suspicious) use
ceramic resonators rather than real crystals and thus may have extremely
poor frequency stability. See here
http://jorisvr.nl/arduino_frequency.html
for an example.

Is there some reason you are using a 16.9344 MHz oscillator rather than
16.0? The processor will probably work, but timing of Arduino functions
like millis() and software serial baud rates will be affected.

On Wed, Dec 10, 2014 at 2:19 PM, folkert <folkert at vanheusden.com> wrote:

> > I'm experimenting a bit with time keeping.
> > For that I use cheap low power hardware like raspberry pies and
> > arduinos.
>
> Hi people,
>
> Thanks for all the replies! Took a bit to respond but I had the flu.
>
> My objective is, to get the best precision/accuracy possible with said
> hardware.
>
> The first step is preparing an arduino. I found one that has an easy to
> desolder crystal:
>
> http://upload.wikimedia.org/wikipedia/commons/thumb/0/04/Arduino_Mini.jpg/170px-Arduino_Mini.jpg
> Bought a couple of those and some of these:
>
> http://www.aliexpress.com/item/Precision-TCXO-square-wave-oscillator-TCXO-16-9344MHz-line-rectangle/1104200137.html
>
> While waiting for these and the parts for the schematics, I'm toying
> around with implementing ntp servers (well, sntp) for arduino. With
> lots of blinkenlights of course and with ethernet. Not trivial I can
> say.
> This is the jitter plot of a test where time is fed from an RTC module.
> I did not plot the drift but it is +/- 120 seconds in the 3.8 days I
> measured it.
> http://vps001.vanheusden.com/~folkert/aRTC.png
>
>
> Folkert van Heusden
>
> --
> ----------------------------------------------------------------------
> Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 

--Jim Harman