[ntp:questions] GPS_NEMA, but high offset and jitter?

unruh unruh at wormhole.physics.ubc.ca
Thu Feb 25 22:53:05 UTC 2010


On 2010-02-25, Kelsey Cummings <kgc at sonic.net> wrote:
> Rob wrote:
>> This is normal with NMEA.  You never will get stable time when using
>> an NMEA time source.  For that, you need PPS.  Your PPS is apparently
>> not working.
>
> It feels like I must be missing something here, running with -d I can 
> confirm that PPS doesn't appear to be working - after enabling flag3 as 
> well.
>
> 25 Feb 13:53:21 ntpd[75656]: 0.0.0.0 041d 0d kern PPS enabled
> 25 Feb 13:53:21 ntpd[75656]: 0.0.0.0 042d 0d kern PPS no signal
> ..
>
> Is there any other way to watch the signal to see if it's reaching the 
> serial port correctly?

gpsd watches the serial interrupt. If you also have the kernel watching
the interrupt, things might get confused. 

>
> -K




More information about the questions mailing list