Hi all, I am setting up chronyd on an embedded Linux device to synchronize the system clock using a GPS module. The GPS device sends NMEA strings over the character device /dev/ttyAMA1 and I have also configured /dev/pps0, both of which appear to be working OK.
The system is running Ubuntu 18.04 and the latest package versions are chronyd 3.2 and gpsd 3.17. I configured gpsd to listen to the serial device and then added these lines to my chrony.conf: refclock SHM 0 refid GPS precision 1e-1 offset 0.9999 delay 0.2 refclock PPS /dev/pps0 refid PPS When I run `chronyc sources` they both seem to be kind of working: 210 Number of sources = 2 MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== #- GPS 0 4 377 12 +128ms[ +128ms] +/- 200ms #* PPS 0 4 377 12 +6ns[ +119ns] +/- 203ns However it looks like the GPS source is “not combined”. Is this a degraded state, e.g., it is using one of these two sources? Also, I am not sure why the LastRx from the PPS (or frankly either) ticks upwards so long—shouldn’t it constantly be receiving updates? I am just using the precision / offset / delay figures that several examples use. Is there documentation on calibrating these values? Finally, I read that using Unix sockets rather that shared memory is preferable, but my chronyd does not seem to create those sockets. Thanks, RyanN�����r��y隊W!���ǫ�����-r�+n��\�� "�����r��z)��.n7��Z+��izf���k�|�����z�\��'�۱}���*+�����)��.n7��:蹹^f��X��f���܆�'�۱}���*+