Hi,
Thanks for providing this mail-list. I am using microcontroller as a fake GPS in our project for time sync in gps-denied environment.
The microcontroller generates PPS and NMEA messages to Nvidia Jetson computer running Ubuntu 18.04. The PPS is stable as tested in Oscilloscope. The NMEA message is copied from a real gps record.
/etc/chrony/chrony.conf:
pool ntp.ubuntu.com iburst maxsources 4
pool 0.ubuntu.pool.ntp.org iburst maxsources 1
pool 1.ubuntu.pool.ntp.org iburst maxsources 1
pool 2.ubuntu.pool.ntp.org iburst maxsources 2
driftfile /var/lib/chrony/drift
allow
# set larger delay to allow the NMEA source to overlap with
# the other sources and avoid the falseticker status
refclock SOCK /var/run/chrony.ttyTHS0.sock refid GPS precision 1e-1 offset 0.9999
refclock SOCK /var/run/chrony.pps1.sock refid PPS precision 1e-7
Start commands:
sudo killall -9 gpsd chronyd
sudo chronyd -f /etc/chrony/chrony.conf
sleep 2
stty -F /dev/ttyTHS0 speed 9600
sudo gpsd /dev/ttyTHS0 -F /var/run/gpsd.sock
cgps -s result:
chronyc sources -v result:

sudo ppstest /dev/pps1 result:

Everything looks good, gpsd can parse the NMEA right, PPS is showing good. But chrony is not working.
Any suggestions will be great, thank you so much!
Best regards,
-------------------------------------------------Lin Zhao