Hello Everyone,
I have a U-Blox NEO-M9N (SparkFun), connected via USB-C (for data and power) to Linux Mint 20.3 64-bit, running GPSD v3.24 (compiled from source) and CHRONY v4.2 (compiled from source).
The issue I am having is that when I run gpsd it auto-reconfigures the M9N receiver.
What I mean is this: I have used U-Center from u-blox to configure my M9N so that it only pushes GPGGA and GPRMC NMEA messages. If I run gpsd with the "-b" flag option, then I can see in gpsmon only the GPGAA and GPRMC messages, yay...it works! BUT...if I run gpsd as I normally would: "gpsd -n /dev/ttyACM0", then the M9N starts spitting out a TON of NMEA message types:GPGSV, GPRMC, GPGGA, GPZDA, NAV, etc...etc...
The problem is that if I leave gpsd running with "gpsd -b -n /dev/ttyACM0", then the CHRONY socket "refclock SHM 0 refid GPS precision 1e-3 poll 3" stops communicating with GPSD: the reach slowly fades away from 377 down to 0.
If I run gpsd without the "-b" option, then the reach gets to 377 very quickly on the CHRONY socket but the u-blox spits out a ton of NMEA messages.
Question: how can I prevent GPSD from modifying my u-blox receiver whilst at the same time have the CHRONY socket SHM 0 also work properly ??
Thanks,
Tom