[ntp:questions] ntpd connect gpsd shared memory driver
agcarver+ntp at acarver.net
Tue Jun 18 07:22:11 UTC 2013
On 6/17/2013 16:55, Richard Cagley wrote:
> Based on poor luck with ntpd/pps, I'm trying to have ntpd use the shared
> memory driver provided by gpsd. Do I need to give a special flag to
> configure for ntp to tell it to build in support for the shared memory
> Using this for my ntp.conf
> server 127.127.28.0 minpoll 4
> fudge 127.127.28.0 refid NMEA
> I get nothing
> / # ntpq -p
> remote refid st t when poll reach delay offset
> SHM(0) .NMEA. 0 l - 16 0 0.000 0.000
> but, gpsd is patiently waiting for something to happen...
> / # gpsd -b -N -D5 /dev/ttyO0
You need -n (lower case N) to force gpsd to start collecting data
automatically. It normally waits for something to connect to its TCP
port and enable data collection (the WATCH command as you discovered).
If you start with just:
gpsd -bn /dev/ttyO0
You'll find the SHMs are populated after a few seconds (once gpsd syncs
with the data stream from the receiver).
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