BeagleBone Black GPS PPS and Chrony for time sync

To Jack,
you cannot run gpsd separately because operating system is trying to run it as a service process. It fails, but the process still seems to be “running” in some way.
Stop it first with service gpsd stop, then you should be able to run gpsd from userspace normally.

sobota, 13. marec 2021 ob 20:00:50 UTC+1 je oseba Jack Czerkawski napisala:

Thank you Jaka that helps me a lot.

But I have right now a diffrent problem. I am trying to make a NTP server. I am using PocketBeagle and GPS module - UART GPS NEO-7M-C .
I have connected it like that:
PB_UART4-Tx(P2.07)- GPS NEO-7M-C Rx
PB_UART4-Rx(P2.05) - GPS NEO-7M-C Tx

After running gpsd with /dev/ttyS4 I’m getting normal GPS data (NMEA) using cgps but when I run chrony It is not giving me any result from my GPS source.

In dmesg I can see that gpsd is forces my device (/dev/ttyS4) as new pps source:

[ 385.668490] pps_ldisc: PPS line discipline registered
[ 385.670656] pps pps1: new PPS source serial4
[ 385.670761] pps pps1: source “/dev/ttyS4” added

Does anyone know how to turn off pps support in gpsd. So I can get only GPS time in chrony?

I suppose you could do that by omitting the device parameter from gpsd command line. Try gpsd -D 5 -n -N /dev/ttyO4 , and comment out the refclock PPS /dev/pps0 lock NMEA line from chrony configuration file before restarting chrony.

četrtek, 18. marec 2021 ob 11:51:46 UTC+1 je oseba Jack Czerkawski napisala: