[time-nuts] Features of a Precision Clock?

[Glenn]

Good to hear that this project is coming along nicely!


>>(1) Synchronize the 1 PPS output rising edge to be near a 1 PPS input
> >>pulse on a one time basis (the 1 PPS edge will have an error of a few
> >>instruction cycles which are each 4/Fin long).  If this was done the
> >>manual setting would be removed.


Would this be used to sync a 10 MHz osc to a 1 PPS from a GPS?
If yes, then definately.

Another idea along these lines: make the clock able to set it's time
from a GPS (Oncore would be my choice).


>>(2) Add another mode of operation where the clock runs on it's internal
> >>RC oscillator and the timing is determined by an external 1 PPS that
> >>needs to always be connected.


Not a bad idea, but #3 seems like a better idea:


>>(3) Add a backup Real Time Clock with it's own coin cell battery to
> >>allow using the clock in a portable application and allow the clock to
> >>be shipped while running.  The chip has a 0.1 ppm aging trim capability
> >>and there could be a provision to automatically trim it when one of the
> >>above precision input frequencies is applied for maybe a day.  Then when
> >>the input frequency is disconnected the clock would continue to tell the
> >>time.  There are also many options for alarms.


Yes! Yes! Yes! An alarm would be great. "Snooze" would make it even better!
Although, something I could hook a relay up to would be MUCH better than
a buzzer. This would then replace my bedside alarm clock.



> >>(4) Other displays such as fractional Julian Day number, fractional
> >>Modified Julian Day number. sidereal time, or ???


IMHO, features like an alarm, which would make the clock much more
"acceptable" to "significant others" would make it easier to sell (and buy)
than alternate date displays.

cheers,
glenn