u-blox Stationary Mode

[Richard Laager]

There was some discussion on the gpsd-users list a few years ago about
setting the ublox into "stationary mode":

https://lists.gnu.org/archive/html/gpsd-users/2013-11/msg00002.html
https://lists.gnu.org/archive/html/gpsd-users/2013-08/msg00007.html

I'm not 100% sure, but I think I finally have that working, by running
the following before starting gpsd (ignore line wrapping in this email):
gpsctl -t 'u-blox' -b -x
'\x06\x24\xFF\xFF\x02\x03\x00\x00\x00\x00\x10\x27\x00\x00\x05\x00\xFA\x00\xFA\x00\x64\x00\x2C\x01\x00\x3C\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
/dev/ttyAMA0

Oddly, despite setting the proper type with -t, gpsctl still attempts
some type probing (which can be seen with -D 5).

With it set, the Speed value in cgps seems to be lower (typically 0.2
mph or less). Without it, it tends to be a bit higher.

I'm guessing this won't actually do anything useful for ntpd accuracy,
but I thought I'd mention it in case anyone wants to do more testing.

-- 
Richard