[time-nuts] Got 60HZ?

[Michael Poulos]

Chris Albertson wrote:
> What you are doing is "dithering".  That is the "Leap Count".  There is a better
> way that gives you the exact solution.     If you think about it, what is the
> computer doing between counts? nothing really.   Put that time to use.
> Why not measure the the 1Khz period.  Or measure the period of the last
> 1000 counts.  then toggle the output at 60/1000 of that period.  This is a
> "software phase lock loop" .   Another way to think about this is to think what
> would you do if your frqency reference was a one pulse per second "tick".
>
>   
I got the "dithering" idea from an obvious source: the calendar. Not 
knowing about dithering but knowing everyone on the list knows about 
leap time intervals, the term I used is a no-brainer. With a 1HZ output, 
the thing I would do is feed it into an Arduino for the display. If I 
wanted a display with .1 of a sec display added, I'd have let's say the 
ramp-up to HIGH trigger the Arduino and code in time-waste code as 
needed to get the flipping intervals - including any leap wasted CPU 
cycles. Like any frequency multiply scheme you need a really accurate 
reference source... like a Ru movement.