Re: [gpsd-users] Uncertain system time

[Gary E. Miller]

Yo Massimiliano!

On Tue, 1 Oct 2019 20:39:14 +0200
Massimiliano Fago <address@hidden> wrote:

> sorry if the email is a bit off topic.

gpsd time is always on topic here.

> Finally I'm on the finishing line for my time measurement system.

Cool.

> Last Sunday I made the first race and noticed a problem that I
> believe I had not had before.

Not cool.

> The problem lies in the adjustment of time.
> I have to tell you that I turn on the system a few hours before the
> race to give time to level the time.

Yes, that is normal.

> Everything runs on raspberry PI 3 model A + and I also added an
> external RTC (DS3231).

Good.  Have you confirmed that your RTC is used on boot?

> Logically gpsd works properly and with the PPS signal that is always
> present all the time.

Good.

> Last night I wanted to check the problem and left the system on all
> night. This morning I still noticed the uncertainty of the time that
> went from an offset of 0.002 to 999.99 on ntpmon and on gpsd a PPS
> from 0,0000453 to -0.9999.

What versions of gpsd and ntpd?  There was a recent bug in git head,
maybe in 3.19, that did that.

> Honestly, I don't know where I'm wrong.

I would first try gpsd from git head.

> Below is my ntpd.conf file

Where are your other servers?  NTP is designed to require
at least 3 servers.  That whole voting thing.

RGDS
GARY
---------------------------------------------------------------------------
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

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