Yo Achim! > I just added a u-blox 6 GPS mouse, and split the SkyTraq PPS to go > into GPIO 4 and GPIO 18. So three PPS on one RasPi. I'll post > results later today, first I finish to compiling the new kernel with > the new multiple PPS patch.
I'm comparing SkyTraq PPS to the u-blox 6 USB PPS. The offset between
the two varies slowly over a few minutes between 1 milli second and 0.2
millisecond. The SkyTraq jitter is around 0.5 micro seconds, the USB
jitter around 3 micro seconds.
The USB jitter/offset is still a touch better than the time from
nearby RasPi, with serial GPS, over ethernet.
Those numbers from 'chronyc sources', double checked by eyeballing
ppstest.
More to come.
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
g...@rellim.com Tel:+1 541 382 8588
Veritas liberabit vos. -- Quid est veritas?
"If you can’t measure it, you can’t improve it." - Lord Kelvin
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