Re: [chrony-users] Not getting time from gpsd

[Steve Horton <stevejhorton@xxxxxxxxx>]

Agreed. Shms live in /dev along with the real time clocks /dev/rtc0. Your kernel config dictates what's there. Look around in dev and see what shms are there and mod your chrony configuration to point to one of them and check tracking. I'd also comment out all server lines until you get it syncing with the GPS device.

On Aug 6, 2016 11:18 AM, "Bill Unruh" <unruh@xxxxxxxxxxxxxx> wrote:

shm should also work. Question is if they are reading the same shm location.




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On Sat, 6 Aug 2016, Steve Horton wrote:

Not really Chris. I don't see a sock option in your configuration file. Gpsd should write time out to a device
file some where and chrony can read the time from that device file via a Unix domain socket. Like I said..look
into the sock option  and how it relates to gpsd.


On Aug 6, 2016 10:10 AM, "Chris Greenman" <chris.m.greenman@xxxxxxxxx> wrote:

      Same thing.  Already tried it.


      On Aug 6, 2016 6:35 AM, "Steve Horton" <stevejhorton@xxxxxxxxx> wrote:

            I'd look closer at the SOCK option under the refclock section.
            https://chrony.tuxfamily.org/manual.html#refclock-directive

            On Aug 6, 2016 12:00 AM, "Chris Greenman" <chris.m.greenman@xxxxxxxxx> wrote:
            >
            > Hello,
            >     I'm having an issue with getting time from gpsd.
            >
            > My setup is:
            > Raspberry Pi 3 running Jessie Lite
            > USB U-Blox gps
            >
            > gpsd is receiving NMEA from the GPS, cgps also shows time and position properly. 
            >
            > My chrony.conf is:
            >>
            >> server 0.us.pool.ntp.org
            >> server 1.us.pool.ntp.org
            >> server 2.us.pool.ntp.org
            >> server 3.us.pool.ntp.org
            >> driftfile /var/lib/chrony/drift
            >> allow
            >> refclock SHM 0 refid GPS precision 1e-1 offset 0.9999 delay 0.2
            >> makestep 1 -1
            >>
            > Chronyc sources shows this:
            >>
            >> $ chronyc sources
            >> 210 Number of sources = 5
            >> MS Name/IP address         Stratum Poll Reach LastRx Last sample
            >> ===============================================================================
            >> #? GPS                           0   4     0   10y     +0ns[   +0ns] +/-    0ns
            >> ^+ time-c.nist.gov               1   9   375   110    -23ms[  -22ms] +/-   47ms
            >> ^* pool-96-248-122-64.cmdnnj     1  10   377    56  +9749us[  +11ms] +/-   18ms
            >> ^- 104.156.99.226                2   9   377   367    +15ms[  +17ms] +/-  107ms
            >> ^- 4.53.160.75
            >>
            > This system is going to be used on a boat and might not have internet.  I can tell
            that both programs are accessing the shared memory using ipcs -m:
            >
            >> ------ Shared Memory Segments --------
            >> key        shmid      owner      perms      bytes      nattch     status      
            >> 0x4e545030 0          root       600        80         2                       
            >> 0x4e545031 32769      root       600        80         1
            >>
            > Any idea why chrony isn't getting time from the GPS?
            >
            > Thanks