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<div class="moz-cite-prefix">On 16-Mar-18 05:26, Udo van den Heuvel
wrote:<br>
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<blockquote type="cite"
cite="mid:4f709318-f3a5-9be8-b294-29f7e6517609@xs4all.nl">
<pre wrap="">Hello,
I am trying to make a Garmin GPS18x LVC work with my firewall.
Another GPS18x *does* work, attached to this PC.
I keep seeing 100's of ms of offset between the firewall and this
workstation (and the rest of the world) in `ntpq -pn` output.
I also see:
# ppstest /chroot/ntpd/dev/pps0
trying PPS source "/chroot/ntpd/dev/pps0"
found PPS source "/chroot/ntpd/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1521192070.588686508, sequence: 150046 - clear
1521039630.201197096, sequence: 2
source 0 - assert 1521192071.588741114, sequence: 150047 - clear
1521039630.201197096, sequence: 2
source 0 - assert 1521192072.588592010, sequence: 150048 - clear
1521039630.201197096, sequence: 2
source 0 - assert 1521192073.588552381, sequence: 150049 - clear
1521039630.201197096, sequence: 2
source 0 - assert 1521192074.588503724, sequence: 150050 - clear
1521039630.201197096, sequence: 2
source 0 - assert 1521192075.588455899, sequence: 150051 - clear
1521039630.201197096, sequence: 2
source 0 - assert 1521192076.588526746, sequence: 150052 - clear
1521039630.201197096, sequence: 2
^C
Why isn't the clear timestamp incrementing but /is/ the assert timestamp
incrementing?
I tried flag2 of the nmea driver (rising/falling edge) but that did not
bring me a solution yet.
What is happening here, how do I fix this?
Udo
</pre>
</blockquote>
<br>
Start with the hardware. If you connect the failing 18x to the same
port on this PC, does it work?<br>
This will tell you if it's the hardware/software related to the
port, or the 18x.<br>
<br>
If the failure goes with the 18x, did you program the pulse width?
A narrow width might be missed, while a wider one would be caught.
This is especially true where hardware edge detection is used - it
may not be programmed on both edges, leaving you with polling for
the other edge. Are the firmware versions the same?<br>
<br>
If the problem goes with the port, what, exactly is the platform and
how is the 18x interfaced? If by PC you mean an ARM platform, such
as RPi, look at the device tree.<br>
<br>
Finally, does the behavior change outside the chroot?<br>
<br>
<br>
<br>
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