David J Taylor schreef: > The fact that you have a 0.2s offset suggests you are synching to the > trailing edge of the PPS signal and not the leading edge.
The NMEA output would be my prime suspect. It is not surprising to have an offset there. The time in an NMEA sentence doesn't tell you what time it is "now", but instead it specifies the point in time that the rest of the data (e.g. position) refers to. Also, NMEA sentences lack proper time markers. It's always tricky business to get clock synchronization from NMEA alone. I would say it is impossible. The Garmin GPS 18 LVC manual explicitly mentions that emitted NMEA sentence describe the when and where of the *previous* rising edge of the PPS signal. It does not specify how long after that edge it will give you the NMEA, or even that this time will be constant. N _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
