ublox refclock

Trevor N. trv-n at comcast.net
Sat Nov 30 02:18:50 UTC 2019

On Wed, 27 Nov 2019 22:08:48 -0500, Trevor N. <trv-n at comcast.net>
>I have already begun collecting F9T data with gpsd-3.19 (kernel PPS
>enabled) through shm on the latest ntpsec.  I'll post 1-day output as
>soon as it's available.
The results attached indicate a problem with my setup. Every 2 to 3
hours a one-second offset appears on SHM(1).  There could be several
problems, so I made a few changes at once to return to collecting data
as soon as possible:

* The F9T was not in its factory configuration, so I restored its
default configuration. I then disabled all systems besides GPS,
increased the mask angle to 20 degrees, and disabled NMEA output.

* The serial line rate was only 9600bps, which might have been causing
the module's output buffer to overflow, or possibly the idle time was
not sufficient for gpsd to resolve the second offset; Increased to

* The module's PPS offset was -100ms; changed to +0.1ms

Collection has been restarted.

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