[time-nuts] Arduino GPSDO with 1ns res TIC

Chris Albertson albertson.chris at gmail.com
Sat Mar 1 20:19:34 EST 2014


The good thing about Lars posting his code is that if you think you
see an improvement you can make it and test your idea.  I intend to
start doing just that but Chinese parts take about 30 days to get here
and I'll just have to wait.  My first steps will be to make the
software vary easy to understand, to verify and modify.   I'll likely
post my version to GitHub.

BTW I think "P" terms do integrate in a way because it's a correction
term you apply to the current DAC value.  The current DAC value is the
sum of all the corrections in the past.    So it may look like

With luck this could snowball.  If it works well more people will use
it and with more users, some of them will think of improvements that
make it work better.

On Sat, Mar 1, 2014 at 12:29 PM, Magnus Danielson
<magnus at rubidium.dyndns.org> wrote:
> Hej Lars,
> Impressive build in all it's simplicity.
> Your filtering equations look strange.
> Rather than having a PI loop it looks like both the P and I branch
> integrates. I'm also unclear about the loop gain changes by the pre-filter
> averager.
> Will have to look more at your code.
> Cheers,
> Magnus


Chris Albertson
Redondo Beach, California

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