[LinuxPPS] taming the gps18x

[Udo van den Heuvel]

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