Some suggestions:
1) use ntpshmmon command to test gpsd->chronyd shm communication. It should output a line (starting with NTP<n>) every second.
2) add "-f 8N1" option to GPSD_OPTIONS (if your GPS uses 8n1 data-bit/parity/stop-bit)
3) do not use the /dev/pps0 device as gpsd device, but only as a chronyd refclock
4) backlist the pps_ldisc module, if it is automatically loaded by the system (pps_gpio should be used in this case, and not pps_ldisc)
5) do not add any custom "poll <n>" parameter to refclock items. For some reasons, in my system, custom low poll values seem to stop the gpsd readings.
6) test with a foreground gpsd session
1) use ntpshmmon command to test gpsd->chronyd shm communication. It should output a line (starting with NTP<n>) every second.
2) add "-f 8N1" option to GPSD_OPTIONS (if your GPS uses 8n1 data-bit/parity/stop-bit)
3) do not use the /dev/pps0 device as gpsd device, but only as a chronyd refclock
4) backlist the pps_ldisc module, if it is automatically loaded by the system (pps_gpio should be used in this case, and not pps_ldisc)
5) do not add any custom "poll <n>" parameter to refclock items. For some reasons, in my system, custom low poll values seem to stop the gpsd readings.
6) test with a foreground gpsd session
Statistics: Posted by lazacz — Sat Sep 13, 2025 2:33 am