3.22 not sending PPS to SHM

[David Taylor]

Yes, I know this sounds unlikely, so perhaps I#m doing something wrong here!

Raspberry Pi, current OS: Linux RasPi-18 4.19.66-v7+ #1253 SMP Thu Aug 
15 11:49:46 BST 2019 armv7l GNU/Linux

PPS check:

pi@RasPi-18:~ $ sudo ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1610274653.008196289, sequence: 1082 - clear 
0.000000000, sequence: 0
source 0 - assert 1610274654.008083166, sequence: 1083 - clear 
0.000000000, sequence: 0
source 0 - assert 1610274655.007973304, sequence: 1084 - clear 
0.000000000, sequence: 0


Never had gpsd installed before.  Compiled 3.22 from scratch.  Build log:
~~~~~~~~~~~~~~~~~~~~~~~~~~~
scons: done building targets.
WARNING: asciidoctor not found.
WARNING: Some documentation and html will not be built.
WARNING: gpsplot is missing required runtime module matplotlib
WARNING: xgps and xgpsspeed are missing runtime dependencies
WARNING: ubxtool and zerk are missing optional runtime module serial
WARNING: Python2.7 too old (need 3.6): gps/aiogps.py will not be installed
Ensure your PYTHONPATH includes /usr/local/lib/python2.7/dist-packages/

Could install asciidoctor
Couldn't find matplotlib - python3-matplotlib
Could install python3 python3-matplotlib python3-serial version 3.5.3

scons: done building targets.
WARNING: gpsplot is missing required runtime module matplotlib
WARNING: xgps and xgpsspeed are missing runtime dependencies
WARNING: ubxtool and zerk are missing optional runtime module serial
WARNING: Python2.7 too old (need 3.6): gps/aiogps.py will not be installed
Ensure your PYTHONPATH includes /usr/local/lib/python2.7/dist-packages/
~~~~~~~~~~~~~~~~~~~~~~~~~~~

"cgps -s" works as expected.

NTP configuration extract:

~~~~~~~~~~~~~~~~~~~~~~~~~~~
server 127.127.28.0 minpoll 4 maxpoll 4 prefer
fudge  127.127.28.0 time1 0.150 refid GPS

server 127.127.28.1  minpoll 4 maxpoll 4 prefer
fudge  127.127.28.1  refid PPS
~~~~~~~~~~~~~~~~~~~~~~~~~~~

NTP result:

pi@RasPi-18:~ $ ntpq -pn
     remote           refid      st t when poll reach   delay   offset 
 jitter
==============================================================================
*127.127.28.0    .GPS.            0 l    8   16  377    0.000    1.401 
 2.349
 127.127.28.1    .PPS.            0 l    -   16    0    0.000    0.000 
  0.000
+192.168.0.20    .GPS.            1 u   26   32   77    2.552   -6.524 
 2.954
+192.168.0.3     .kPPS.           1 u   27   32   77    2.495   -6.381 
 2.672
+192.168.0.71    .kPPS.           1 u   24   32   77    3.191   -6.966 
 2.396
 uk.pool.ntp.org .POOL.          16 p    -   64    0    0.000    0.000 
  0.000
-162.159.200.1   10.21.8.19       3 u   63   64    3   24.421   -1.616 
 6.869


So the "127.127.28.1" is either not being seen by NTP or NTP isn't 
seeing the data, or?

I tried with and without the "prefer" on the  127.127.28.1  server line. 
 Many Web sites show the prefer present, but my understanding is that 
the prefer should be on the source of time-of-day data, and not on the 
PPS line.

At the moment, I'm stuck.

Is there a simple way to test whether the SHM 1 segment is being filled?

Thanks,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv