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Re: [gpsd-dev] Port to QNX: PPS without SHM?
From: |
Hal Murray |
Subject: |
Re: [gpsd-dev] Port to QNX: PPS without SHM? |
Date: |
Mon, 21 Dec 2015 20:20:53 -0800 |
address@hidden said:
> So this at least suggests that ntpd is interpreting the PPS signal, but the
> offset it pretty extreme. Any strategies for addressing that?
The offset may be accurate. It could also be triggering on the wrong edge.
There is a fudge flag to flip that.
What type of GPS receiver are you using? Most low cost units are crappy for
timekeeping.
Can you setup a few external servers? (If you mark the PPS and JSON
"servers" as noselect, they won't confuse the timekeeping but will collect
all the data for ntpq and peerstats.)
That should give you time that is accurate enough to sort out the PPS
polarity. Once you get that right, the PPS will probably be more accurate
than the network servers.
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