rtxo wrote: > Patrick Klos wrote: > >> I'm sure you can't rely on the NMEA strings coming out with any specific >> relationship to the pulse. We've seen Garmin GPS's get very busy inside >> and skew the NMEA strings all over the place, including after the NEXT >> PPS. > > > I'd suggest turning off all output of the GPS, except for the > $GPGGA or $GPRMC strings, and turning on the PPS. This should > provide good operation with the Dave Mills NTP software. > I've run a Garmin GPS35 this way and have had consistent > 1 microsecond PPS performance with NTP.
The NMEA driver defaults to using only the RMC message, so unless you use a mode mask to also look for the others, nothing but RMC should be needed or transmitted. Re. the GPS 18: In NMEA mode the default selection of messages is so large that it takes more than a second to send them all, meaning that you lose every other second update! Limiting the number of messages is therefore a required step to get optimal timing. Terje -- - <[EMAIL PROTECTED]> "almost all programming can be viewed as an exercise in caching" _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
