[gpsd-users] TOFF and PPS values from gpspipe

[Kaya Saman]

Hi,

I'm writing a script in order to be able to display certain information from GPSd on a 20x2 line character LCD display.

Basically what I want to figure out is how gpsmon arrives at the TOFF and PPS values in the GSA + PPS window. Is there a formula for it?

Taking the example from the docs:

https://gpsd.gitlab.io/gpsd/gpsd_json.html

{"class":"PPS","device":"/dev/ttyUSB0",
     "real_sec":1330212592, "real_nsec":343182,
     "clock_sec":1330212592,"clock_nsec":343184,
     "precision":-3}

while in gpsmon it shows the PPS as -0.00000xxxx <- where 'xxxx' changes on each pulse.

I've also had a look at the gpsmon.c file: https://github.com/mutability/gpsd/blob/master/gpsmon.c

but couldn't find anything....

Would someone be able to help?

Many thanks.

Kaya