Score:0

Can chrony be configured as ntp server with gpsd without PPS

zw flag

I'm wanting to setup an ntp server on Ubuntu 18.04 or later. This PC will have little to no access to internet. I currently have a ublox 8 GPS USB mouse that does not support PPS. I have followed the setup for both gpsd and chrony. gpsd is working but does not share time information with chrony via the shared memory or socket. Is this setup possible?

Score:0
sl flag

The gpsd/chrony docs clearly state that you need a PPS.

GPSD, NTP and a GPS receiver supplying 1PPS (one pulse-per-second) output can be used to set up a high-quality NTP time server.

The list of compatible hardware also lists ublox-8 devices, but IIRC when I ordered mine the important bit was to get those devices that have the PPS signal linked (physically). IIRC there were even soldering howtos for some of them to link the PPS signal as an after-market upgrade.

Score:0
us flag

Abolutely.

I am currently using a u-blox GPS hooked up via USB.

I just added this to the bottom of /etc/chrony/chrony.conf

#GPS Sources
refclock SHM 0 refid GPS precision 1e-1 offset 0 delay 0 stratum 2
refclock SOCK /var/run/chrony.ttyACM0.sock refid PPS
fadedbee avatar
us flag
I am having trouble getting chrony working without a PPS, could you have a look? https://unix.stackexchange.com/questions/716591/using-gpsd-and-chrony-without-pulse-per-second
Morten Nissov avatar
us flag
how do you get PPS this way? Is it just stamping GPS on arrival? Also I assume GPS sends more NMEA messages than just timing right?
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