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Re: [gpsd-users] Garmin 18X-5Hz
From: |
David J Taylor |
Subject: |
Re: [gpsd-users] Garmin 18X-5Hz |
Date: |
Sun, 14 Aug 2016 09:14:37 +0100 |
Dear Gary, dear Frank
You convinced me that the uputronics is the better choice over the
adafruit. I read the specs. The Adafruit is limited to 112 kbaud. The
uputronics is four times as fast.
[]
I tried to make a standalone time server with GPS, gpsd and NTPd. The
approach of David Taylor (who uses a network connected system) of giving
the gpsd coarse clock a high stratum and the pps stratum 0 did not work
because you cannot get a lock this way. But when you have two stratum 0
clocks and there is jitter on the "coarse" one you don't get best
results either.
[]
Regards
Robin
=========================================
Robin,
I have tested using /just/ a GPS/PPS Uputronics module to provide an NTP
server with no Internet connection and it works just as expected. It's on
my Web site:
http://www.satsignal.eu/ntp/Raspberry-Pi-quickstart.html#stand-alone
The serial support on the Raspberry Pi changed with model 3, and with the
Jessie OS, and may still be changing so be prepared to fiddle around a
little. You need the "prefer" flag against the serial "time of day" source,
not against the PPS source (as that had no time-of-day information). In
ntp.conf:
# Kernel-mode PPS reference-clock for the precise seconds
server 127.127.22.0 minpoll 4 maxpoll 4
fudge 127.127.22.0 refid kPPS
# Coarse time reference-clock - nearest second
server 127.127.28.0 minpoll 4 maxpoll 4 iburst prefer
fudge 127.127.28.0 time1 +0.105 flag1 1 refid GPSD stratum 1
The older Garmin GPS18 LVC needs to be outdoors as it has a relatively
insensitive receivers, but the GPS18x LVC works OK for me located indoors on
the top storey of a building near a south-facing wall.
Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: address@hidden
Twitter: @gm8arv
- Re: [gpsd-users] Garmin 18X-5Hz, (continued)
- Re: [gpsd-users] Garmin 18X-5Hz, Roger Oberholtzer, 2016/08/18
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Robin Schwab, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Frank Nicholas, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Robin Schwab, 2016/08/13
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/13
- Re: [gpsd-users] Garmin 18X-5Hz,
David J Taylor <=
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/14
- Re: [gpsd-users] Garmin 18X-5Hz, Robin Schwab, 2016/08/14
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/14
- Re: [gpsd-users] Garmin 18X-5Hz, Robin Schwab, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Robin Schwab, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Alexander Carver, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Alexander Carver, 2016/08/15