[time-nuts] NTP server using an OCXO, GPS chip and Raspberry Pi

[Matthias Welwarsky]

On Montag, 27. April 2020 08:47:45 CEST Hal Murray wrote:
> You could also use the Pi for the microcontroller.  There is an API to the
> Kernel timekeeping routines.  Try man ntp_adjtime.  There are 2 knobs.  One
> is to adjust the speed of the clock, aka correct for the drift.  The other
> is to adjust the offset by adjusting the speed to be a bit fast or slow for
> the right amount of time.

That is effectively one of my current projects. Though not targeting the 
RaspberryPi, it will be a "cape" for the Beaglebone Black. It's a direct 
adaptation of my Rb-GPSDO, using the same TIC and DAC, but instead of a 
dedicated micro controller, the control software will run as a program on the 
BBB. The 1PPS signal of the GPS is connected to a GPIO pin, too, so it can 
serve as an input to a time server.

BR,
Matthias