> > I have one general question. I don't believe that an internal crystal in the > > microcontroller will have the accuracy or precision required to have better > > than a few milliseconds of accuracy (whereas NTP likes to live in the > > microsecond realm), though I very well could be wrong on that one. > > Accuracy is not a problem. You can measure that and correct for it. > > Most modern kernels have a side door used by ntpd to adjust the clock > frequency. Typical values are few 10s of PPM and it's easy to measure down > 0.001 PPM or better. The NTP world calls that drift. If you have a PC or > Raspberry Pi running Linux or *BSD and ntpd you can find the drift.
Hmmm, I believe Eamonn is going to use a microcontroller. They usually don't run linux or something like that. In a distant past I tried replacing the clock-crystal of an arduino with an OXCO. That was not succesful but that was because I realised I would have to make changes to e.g. the bootloader and such so that things would still have correct bitrate on the serial pins. Hmmm, maybe if I just had put code on it that would simply output something over the serial pins on a known baudrate, I could've checked if it indeed worked at the electronics-part. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
