[ntp:questions] Mixing .20 and .22 for a PPS signal
john.thurston at alaska.gov
Fri Feb 15 19:58:42 UTC 2019
I'm not new to ntpd, but am trying to understand it (and its use with
GPS signals) better. In this case, I'm working with ntpd 4.2.8p10 on
several Pis running minimal raspbian, with MTK3339-based GPS receivers.
What I'm trying to understand better is the interaction of the
127.127.20.u and 127.127.22.u drivers.
I've quieted my GPS module so it sends only $GPGGA sentences at 9600
baud. With that, I find it with:
server 127.127.20.0 mode 0x12
To grab the PPS signal, I can then:
fudge 127.127.20.0 flag1 1
But I can alternatively grab the PPS signal from the .22 driver with:
How are these two methods of grabbing the PPS signal different, and why
might one method be preferred over another?
Do things because you should, not just because you can.
John Thurston 907-465-8591
John.Thurston at alaska.gov
Department of Administration
State of Alaska
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