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Re: [gpsd-users] Garmin 18X-5Hz
From: |
Gary E. Miller |
Subject: |
Re: [gpsd-users] Garmin 18X-5Hz |
Date: |
Thu, 11 Aug 2016 12:19:46 -0700 |
Yo Miroslav!
On Thu, 11 Aug 2016 16:07:06 +0200
Miroslav Lichvar <address@hidden> wrote:
> > > Is this any problem for gpsd and time synchronization?
> >
> > On theory, no. In practice, never tested.
>
> gpsd supports detection of 5 Hz PPS, but there is a problem that it
> always sets the fractional part of the timestamp to zero, so with 5 Hz
> PPS the offsets have an error of 0.0, 0.2, 0.4, 0.6 and 0.8 seconds.
Ouch. If we can get a real test case that should be easy to fix.
OTOH, ntpd will not accept time corrections faster than every 8 seconds
without a patch. I find that every every 16 or 32 seconds gives better
results. Even longer may be even better, depending on local clock
stability.
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
address@hidden Tel:+1 541 382 8588
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- [gpsd-users] Garmin 18X-5Hz, Roger Oberholtzer, 2016/08/10
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/10
- Re: [gpsd-users] Garmin 18X-5Hz, Miroslav Lichvar, 2016/08/11
- Re: [gpsd-users] Garmin 18X-5Hz,
Gary E. Miller <=
- Re: [gpsd-users] Garmin 18X-5Hz, Miroslav Lichvar, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Roger Oberholtzer, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Miroslav Lichvar, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Roger Oberholtzer, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Miroslav Lichvar, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/15
- Re: [gpsd-users] Garmin 18X-5Hz, Gary E. Miller, 2016/08/12
- Re: [gpsd-users] Garmin 18X-5Hz, Roger Oberholtzer, 2016/08/16