[ntp:questions] setting the time using gps-time and pps without ntpd?
nb at komeda-berlin.de
Tue Apr 22 09:59:50 UTC 2008
recently I tried building a microsecond precision timeserver using a
gps-device with pps signal.
The gps-data is transmitted via usb, the pps signal via the rs232
carrier detect line.
I tried several drivers and they all worked, but I had to figure that
obviously my mainboard (via epia en12000EG) has terrible jitter. - unusable!
To solve the problem I think about simply setting the time every n
seconds according to the collected gps time and the pps-signal. My
system will run off for far less than a microsecond in an interval of
let's say, 20 seconds or so. Like this I would implement a constantly
jumping time, but the amount of jumps would be extremely small.
Since I learned that timekeeping is a very complex topic, I thought, I'd
better ask on this list, before I build something troublesome without
What do you think?
With best regards,
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