Re: [chrony-users] Discover when a time sync has been performed

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Yes, the GPS is pure NMEA, no PPS info is available :(

Situation is the following: In-car device, with GPS+3G modem, making some tests/measurements and sending them to a remote server.. So, I can not wait for chrony to set itself, and that's why I ended up using makestep.

2013/7/4 Bill Unruh <unruh@xxxxxxxxxxxxxx>
On Thu, 4 Jul 2013, Ignacio Verona Ríos wrote:

Hi Bill,

yes, the rapspi is sometimes powered-off, specially now while I'm testing
the software. No process other than chrony is modifying the time, and
sometimes the board is powered-off for many hours (overnight), and so will
be the real behaviour of the final app.

Ah. So you want chrony to start up with the initstepslew  directive in
chrony.conf with a low time to allow it to set itself initially. You should
sometimes leave it on for a while so that the drift file can be properly
populated. But all of the ntp programs are designed to discipline a clock over
a long period of time, not in a stop and go fashion. It is ok with chrony if
it is only connected to the net sporadically (but for the initstepslew it
should be connected when it boots up).

I'm thinking about buying an RTC clock. They are cheap (15€) and maybe
connecting it to the GPIO ports help... but I'd like to stay with a pure
software source.

The problem is that none of the program can do anything if there is no time
source of any kind. They cannot pull time out the air.

You say you have  a gps attached. Does it have PPS? or is it just the nmea
sentences? Is it also switched on when the pi is switched on or is it on
permanantly? They also take a while to get a decent time.

Ie, telling us in some detail what your situation is might allow us to give
better advice.

2013/7/4 Bill Unruh <unruh@xxxxxxxxxxxxxx>

On Thu, 4 Jul 2013, Ignacio Verona Ríos wrote:

 Thanks again! Yes, I'm using 1.24 and now realized the log is there:

Jul  3 20:39:37 m2m-probe1 chronyd[2077]: System clock was stepped by

829.745 seconds

Jul  3 21:12:49 m2m-probe1 chronyd[2023]: System clock was stepped by

3057.778 seconds

That is looking seriously sick. It steps the clock, and 33 minutes later it
steps it by 50 minutes?

Jul  3 21:34:59 m2m-probe1 chronyd[2108]: System clock was stepped by

21.122 seconds

Jul  3 22:46:03 m2m-probe1 chronyd[1983]: System clock was stepped by

1698.671 seconds

Jul  4 09:17:25 m2m-probe1 chronyd[2047]: System clock was stepped by

32109.587 seconds

and here by 9 hours? Are constantly switching off and on you RPi?

Jul  4 10:27:34 m2m-probe1 chronyd[1992]: System clock was stepped by

36102.593 seconds

and an hour later by 10 hours?

Is your program altering the clock itself?

Jul  4 13:41:12 m2m-probe1 chronyd[2015]: System clock was stepped by

3942.919 seconds

 Thank you very much!

2013/7/4 Miroslav Lichvar <mlichvar@xxxxxxxxxx>

 On Thu, Jul 04, 2013 at 04:32:04PM +0200, Ignacio Verona Ríos wrote:

Hi Miroslav,

thanks for your answer. It partially solves my question, but I'm not
to see the entry in the tracking log when makestep is applied. Last
of the file look like this:

 2013-07-04 13:05:17     3     82.620     46.004 -2.830e-03

2013-07-04 13:05:21     3     82.127     43.920 -2..164e-03

2013-07-04 13:05:25     3     81.555     42.269 -1..921e-03

 Should I expect some "Makestep OK" message? or it's a different state?

Not in the tracking log, but in the system log there should be a
"System clock was stepped by x seconds" message.

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