[ntp:questions] Fwd: Re: NetBSD GPS/PPS using 4.2.6p3

A C agcarver+ntp at acarver.net
Fri Aug 26 20:14:22 UTC 2011


On 8/26/2011 02:30, David Lord wrote:
> A C wrote:
>>> I will try to capture the outgoing serial data sometime either this
>>> weekend or the next when I have a bit more time. I'll send it along to
>>> the list as soon as I do. For now I'll leave things using PPS only and
>>> see how it works. But I still want to eventually get the GPS refclock
>>> working along with PPS just to have a backup clock for network outages.
>>
>> Ok, so I've spliced up a serial tap cable to snoop on the data heading
>> out towards the GPS. Unfortunately I can't seem to decode it. No
>> amount of changing baud rates, stop bits and parity seems to show me
>> anything but a stream of unreadable binary data.
>>
>> It seems to be coming out at 4800 baud although stty says the output
>> speed of the port is 9600. The data seems to have a regular pattern to
>> it with a few of the bytes changing.
>>
>> If anyone can think of a utility that will attempt to autosync to the
>> data I'm open to suggestions. Otherwise I can try to capture the raw
>> data if anyone wants to look at it. Either way, it only transmits
>> while ntpd is using the port. If ntpd is shut down the data stops.
>
>
>  From type 20 driver reference:
>
> Generic NMEA driver sends a $PMOTG,RMC,0000*ID<cr><lf>
> command each poll interval?


Except I'm not using the Type 20 NMEA driver.  I only have the 22 
PPS_ATOM driver enabled.



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