unruh wrote:
On 2010-02-05, David Lord <sn...@lordynet.org> wrote:
....
What sentences is the nmea sending out? Why not use something like gpsd and the shm driver to combine the nmea and the PPS into one very accurate time stamp?
.... I tried gpsd with shm but without pps in attempt to improve performance of my Globalsat BR-304. Results were worse than when using nmea driver which gave 50% level at offset 9.5ms and jitter 2.6ms, 95% level at 52.4ms and 28.2ms. I didn't even tabulate results as that useless. The BR-304 isn't anywhere near as sensitive as the gps-18x-LVC and in November when weather was bad I could see reach rarely staying at 377 and gpsd was often only showing single sat. Couple of weeks ago even the Garmin was struggling with reach dropping to 0 (layer of ice on window - inside and outside?). At the moment other than when ntpd restarted reach has stayed at 377. I've put checking with gpsd + shm + pps (serial and parallel) with the Garmin on todo list, maybe sometime next week. cheers David _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
