[ntp:questions] ntpd - gpsd communication
uwe at klein-habertwedt.de
Fri Jun 5 10:22:09 UTC 2020
Am 05.06.2020 um 09:53 schrieb ah@***.ru:
> пятница, 5 июня 2020 г., 10:25:24 UTC+3 пользователь Uwe Klein написал:
>> Am 05.06.2020 um 08:36 schrieb ah@***.ru:
>>>> This sounds more like bit errors in serial reception.
>>>> ( i.e errors coming up in all magnitudes.)
>>>> That is reception via NMEA?
>>>> do you check the NMEA checksum ( Portion after * afair)?
>>> Thank you for response. Yes, that is reception via NMEA. No i didn't check checksum, i think gpsd should check it, am i wrong?
>>> I just write to log data from SHM when it's all OK. And try to use this correct log after some time to make ntpd change the time. If you think i do something not correct please tell me, i'll try to do something else
>> can you enable data logging and produce logs from the GPS instances that
>> produce errors? ( all sentences received over some time.)
>> Just from a single sytem.
>> As an alternate take a terminal application configured for 4800baud
>> and for the right serial port and log data via that path.
>> never used gpsd put did my own solution years ago for a special use case:
>> ( one app sources NMEA from the device and reflects that into UDP packets.)
>> the other part is sinking UDP packets and funneling those
>> into NTPD. kind of a primitive gpsd replacement )
> I launched gpspipe -R jn all systems, but it's hard to catch it again. I can be not reproducing for a long time
> Thank you for your decision - did you write it into SHM ? I will see it asaic
SHM :: no.
it creates an "active" pty device for ntpd to attach to.
For ntpd this looks like a regular serial connection.
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