Your 'cheapo' wrist watch probably has a trimmer cap inside that you
can use to tweak it to keep better time.

By tweaking my watch, I went from 4 min/month error to under 4 seconds.
It does help that I wear it all the time (except for showers) so it
is in a 'temperature controlled' environment.

Have you considered adding a 'tweak' routine that adds or subtracts
a count every ## tics to give you a software 'trimmer'?

R

"Sean H. Breheny" wrote:
>
> Hi all,
>
> I don't know if you remember my post a few weeks ago about the frequency
> accuracy of WWV but I finally finished the quick little alarm clock project
> that I was working on and needed that info for. Because I set low (read
> reasonable) goals, this actually turned out to be one of the most pleasant
> and successful PIC projects that I have done. I've already pressed it into
> daily service and it wakes me up quite nicely :-)
>
> If you want to have a look, see:
>
> http://www.people.cornell.edu/pages/shb7/clock/clock.html
>
> It remains to be seen how accurate I've been able to make it. I did one
> test run that was 1.5 days long and it seemed to lose about 0.5 seconds but
> I couldn't tell for sure. I hope to leave it running now for long enough to
> lose several seconds so I can get a good handle on the accuracy. Already
> beats my cheapo wristwatch, though!
>
> Thanks again for your help,
>
> Sean

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