Gary E. Miller via devel writes: > I have some u-blox 6 that are USB mice. I get under 2 uS jitter on a > RasPi, but I have not compared them directly to a GPIO PPS. I should > add that to my long list. It takes a few days for the clocks to settle > in.
Both my NaviSys stick (uBlox6) and puck (uBlox8) show ±1ms jitter over USB on the raspi. I plan to pull out the PPS from the puck some time now that I can use a second PPS. The NavSpark Freebie had ±10ms on my PC, but I don't really know how well the PL2303 driver it was using works (for starters, I don't think anything changed with setting the low_latency option on the interface). I might test the interface from the Freebie again on a rasPi later on, but I don't think it'll come out any better. With PPS over virtual serial I get around ±40µs in total, although there's a noticeable double distribution. I don't have enough data yet to see what's really going on, but it looks like the larger cluster shows around 10µs width over the last hour. > I just powered up a SkyTrax NS-HP, Venus based. Took almost 48 hours > before it reached best accuracy. Huh? the HP is an RTK receiver so you'd need a reference station to make use of that feature set. The timing receiver is the NS-T and yes, if it cold starts and needs to pull the Almanach and do a auto-survey it'll be busy for a while. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ SD adaptation for Waldorf rackAttack V1.04R1: http://Synth.Stromeko.net/Downloads.html#WaldorfSDada _______________________________________________ devel mailing list devel@ntpsec.org http://lists.ntpsec.org/mailman/listinfo/devel