I'm looking for low cost GPS gadgets that are good for time keeping via ntpd.
Any suggestions? I'm interested in not-so-good timing as well as the good stuff that attracts time-nuts. As long as it's low cost. USB doesn't support PPS and it has a bad reputation because it's polled. But the polling is done in hardware with a 1 ms time scale. It won't be great, but for lots of uses it's good enough. The problem is that most of the low-cost GPS toys use the SiRF chip set. It sucks for timing. It looks like the NMEA sentences are sent from a timer with 100 ms ticks. http://www.megapathdsl.net/~hmurray/ntp/GPSSiRF-off.gif The Garmin GPS 18 LVC used to be popular. It's been replaced by the GPS 18x which is much more sensitive. Unfortunately, the timing went way downhill. http://www.megapathdsl.net/~hmurray/ntp/GPS18LVCx-off.gif Anybody know how well the u-Blox chips work? Are they used in any low cost units? (USB ok.) Just to make sure we are on the same wavelength. I don't care about a constant offset. I can easily correct for that. It's the jitter that I don't like. The time scale is wrong. It wanders too slowly. I can't filter it out. -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
