On Thu, Mar 26, 2020 at 8:37 PM chuang213 <chuang...@gmail.com> wrote:
> for the pps part, try the following > refclock SHM 1 refid PPS lock NEMA > > it work for me > > I'm guessing your gpsd is creating the pps device and/or making a shared memory segment from that? I only have a single shared memory entry when I run ntpshmmon: # Name Seen@ Clock Real L Prc sample NTP0 1585280131.870898811 1585280123.169793607 1585280123.000000000 0 -20 ... There is no NTP1 segment as PPS is from the kernel reading the PPS pin from the GPS. I did try it in the off chance ntpshmmon wasn't showing me something but it didn't work. Thanks for the suggestion. On Thu, Mar 26, 2020 at 11:41 AM Dave Hajoglou <dhajog...@gmail.com> wrote: > >> >> >> On Thu, Mar 26, 2020 at 2:00 AM Miroslav Lichvar <mlich...@redhat.com> >> wrote: >> >>> On Wed, Mar 25, 2020 at 03:53:17PM -0600, Dave Hajoglou wrote: >>> > refclock SHM 0 refid GPS precision 1e-1 >>> > >>> > refclock PPS /dev/pps1 lock NEMA >>> >>> There are two issues with this config. One is that the PPS refclock is >>> locking to a non-existent refid >> >> Thanks for taking a look. Good catch on the refids. I have been >> bouncing between different config examples and I had a NEMA refid for the >> GPS SHM at one point then switched to GPS and didn't update the PPS. >> >> I also made sure that PPS was complied into chrony and I even removed the >> PPS support from GPS so that I'm only referencing the Kernel PPS device. >> That did not improve anything >> >> >> >>> and the SHM refclock is not marked as >>> noselect. Try this >>> >>> refclock SHM 0 refid NMEA precision 1e-1 noselect >>> refclock PPS /dev/pps1 lock NMEA refid GPS >>> >>> New config: >> >> refclock SHM 0 refid NEMA precision 1e-1 noselect >> >> refclock PPS /dev/pps0 lock NEMA refid GPS >> >> After running for about an hour I get no selection as expected. But, I >> also get no detection of the PPS either. >> >> >> =============================================================================== >> >> #? NEMA 0 4 377 16 +177ms[ +177ms] +/- >> 100ms >> >> #? GPS 0 4 0 - +0ns[ +0ns] +/- >> 0ns >> >> >> =>The PPS isn't processing or being seen by the logs but the device is >> active: >> >> trying PPS source "/dev/pps0" >> >> found PPS source "/dev/pps0" >> >> ok, found 1 source(s), now start fetching data... >> >> source 0 - assert 1585247167.944762955, sequence: 51077 - clear 0.000000000, >> sequence: 0 >> >> source 0 - assert 1585247168.944717687, sequence: 51078 - clear 0.000000000, >> sequence: 0 >> >> >> =>cgps shows a 3d fix. >> >> >> =>If I remove the noselect, it does pickup the NEMA source but never gets >> data from the pps source. Log entries never show up in refclock. >> >> >> =>If I remove the lock NEMA then the pps source is seen and processed and >> that's when I get the flapping where it selects first NEMA, the GPS refid >> then falls into the majority sync error. This is a weird one as it won't >> process the PPS if I lock it. Does that have to do with the fact that the >> PPS is from GPIO rather than serial? >> >> >> Is there any logging or diagnostic tool usage I can try? The refclock >> and stats logs are lost on me. >> >> >> -- >>> Miroslav Lichvar >>> >>> >>> -- >>> To unsubscribe email chrony-users-requ...@chrony.tuxfamily.org >>> with "unsubscribe" in the subject. >>> For help email chrony-users-requ...@chrony.tuxfamily.org >>> with "help" in the subject. >>> Trouble? Email listmas...@chrony.tuxfamily.org. >>> >>>
