[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Ubuntu 18.04.3 build from source testing

From: Gary E. Miller
Subject: Re: Ubuntu 18.04.3 build from source testing
Date: Mon, 16 Dec 2019 17:41:27 -0800

Yo Steve!

On Mon, 16 Dec 2019 18:26:53 -0600 (CST)
Steve Bourland <address@hidden> wrote:

> Yo Gary!
> Looking fairly good.  Clean install, installed the packages I thought
> I'd need, scons and scons check both passed first go with new
> tarball, and gpspipe -r is reporting:
> $GPRMC,000732.00,A,2926.7338,N,09836.3886,W,0.1346,81.872,171219,4.1,E*41

Some people care about 1 second, so a better confirmation would be nice.

Configure NTPseec to use your gpsd time and look at ntpmon.

Or use cgps against an NTP adjusted time source.

> which looks correct.  There is perhaps a 1 second deviation vs. ntp,
> not sure.  That's where things are off the rails, have installed the
> ntpsec package for Ubuntu server, but gpsd and ntpd don't seem to
> want to talk to each other.

I gotta dozen servers right here using gpsd and ntpd.  Use
ntpshmmon to verify gpsd is sending goot time.  Then look hard at your

> Also had this at gpsd startup:
> gpsd:WARN: KPPS:/dev/ttyS0 kernel PPS unavailable, PPS accuracy will 
> suffer

Yup.  Either your kernel has no KPPS support enabled, or you did not compile
it into gpsd, or both.

Send the complete output of your gpsd build and I can check it for you.

> Assume I need to install a PPS package at some point, but that
> shouldn't prevent ntpd and gpsd from talking to each other.

Correct.  It just makes the time more accurate.

> Historically I have had to issue an stty command to set the serial
> line speed to get the PPS signal to hit, but that hasn't helped here.

serial port speed has zero to do with PPS.

You can now use the -s anf -f options to gpsd instead of stty.

>  I'm sort of at a loss, here are the lines from my ntp.conf file:
> # gpsd time source
> server
> # With time1 0.420 saw ~-200 msec offset, really just punting here
> fudge time1 0.220 refid NMEA
> server prefer
> fudge time1 0.0002 refid PPS

I assume email munged that?

You need more in you ntp.conf than that for it to work.

Modern config is this way:

refclock shm unit 1 minpoll 4 maxpoll 4 refid PPS flag4 1 prefer
refclock shm unit 0 refid GPS flag4 1 noselect

SHM1 always before SHM0 in the file.  With your other servers (pool, etc.)
between them.

But first, confirm that gpsd is sending with ntpshmmon.

Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

            Veritas liberabit vos. -- Quid est veritas?
    "If you can't measure it, you can't improve it." - Lord Kelvin

Attachment: pgpsxdrGut_lS.pgp
Description: OpenPGP digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]