[chrony-users] chrony receiveing GPS timestamp over UDP packet to update SHM

[ Thread Index | Date Index | More chrony.tuxfamily.org/chrony-users Archives ]

Hi All,

    I have one strange question about chrony.
      I am using chrony to keep embedded board system time in sync.. When GPS receiver is connected to board, It can able to sync system time with very negligible deviation. The reference clock for chrony are PPS & SHM.
      Whenever GPS receiver  got new time stamp, application log that value into a file as well as Same timestamp is being given to SHM. GPS receiver is sending updated time stamp at every 200ms.

   I want to simulate same think. For this I am reading logged timestamp from file & sending it through UDP packet at 200ms interval using another application.
    Embedded board receive that UDP packet extract timestamp information & write it into SHM. 
   With this approach chrony able to get SHM data & sync system time. But I am getting lots of deviation. PPS is disable only SHM is enable for this chrony.

   Can any one tell me a better approach or previous experience to achieve this.  

Thanks & Regards,
Pratik Pawar

Here is chrony.conf

#refclock PPS /dev/pps0 lock SHM0
refclock SHM 0 poll 0 offset 0.1 delay 0.5 refid SHM0
makestep 1 10
maxupdateskew 5

local stratum 1

pidfile /mnt/ubi/mk2/chrony/chronyd.pid

driftfile /mnt/ubi/mk2/chrony/chrony.drift

keyfile /mnt/ubi/mk2/chrony/chrony.keys
commandkey 1

logdir /mnt/ubi/mk2/chrony/log
log statistics tracking refclocks
log tracking
logchange 0.1

dumpdir /mnt/ubi/mk2/chrony/log


Mail converted by MHonArc 2.6.19+ http://listengine.tuxfamily.org/