beta-tester/RPi-GPS-PPS-StratumOne

Not working

mitchsfm opened this issue · 12 comments

mitchsfm commented

Using RPi 3, Adafruit GPS V3. Have fix, have data, have pps out of gps.:

output of sudo ppswatch -a /dev/pps0 attached
gpsmon output attached.
cgps output attached.
Suggestions for troubleshooting?
tx from gps to rx pin 10 of rpi header.
rx from gps to tx pin 8 of rpi header
pps from gps to pin 7 of rpi header

Tnx for any help.
screen shot 2018-04-02 at 1 05 47 am
screen shot 2018-04-02 at 12 55 18 am
screen shot 2018-04-02 at 12 59 14 am

Mitch
Opelika, AL
mitchsfm@gmail.com

beta-tester commented

did you used the script without modification?
did you used Raspbian Stretch (Lite) from 2018-03-13 without installing other stuff?
is the gps module attached correctly?

there is something detecting on the GPIO pin 4 (pin 7 on the HAT connector), otherwise ppswatch would show timeouts only.
i guess, the extreme high offset values (its unit is [ns]) will be normal because of missing time sync.
(the differences between two offsets are in the range of ns and µs that looks good)

but you do not get any gps data (time and coordinates).
is TX and RX connected propely or did you swapped the cables by accident?
see picture: Using UART instead of USB

is the baud rate setted up correctly?

mitchsfm commented
mitchsfm commented
beta-tester commented

yesterday an other user was reporting an issue #3 with an RPi3, it was because of the built-in bluetooth interface, that is hijacking the serial port by default.
gpsd was throwing errors because of a busy serial port.
the user disabled the bluetooth interface by adding "dtoverlay=pi3-disable-bt" to the config.txt file.

i added that option to my script yeaterday... but maybe i made something wrong in my script.

if you have time and possibility, would it be possible to test,
if you can get the RPi3+ working when you

  1. install Raspbian Stretch to the SD card newly,
  2. then sudo raspi-config to disable the bluetooth interface there,
  3. make a copy of the config.txt file to see, that changes raspi-conf was making.
  4. then run my script.
  5. restore the changes of raspi-conf to the config.txt file that my script iwas chreating.

maybe there is more going on than disabling the bluetooth via raspi-config.

PS: a RPi Zero with wifi has a built-in bluetooth intrface like the RPi3 / RPi3+
so if you got it working on the RPi3+, maybe you also could test it on a RPi0w and give me feedback, so i can correct my script for RPi3/3+/0w

mitchsfm commented
mitchsfm commented
beta-tester commented

i have my gps-pps-timeserver running on an old RPi1 rev1 with 256MB... just enough computer power for that purpose ... :)

you got it working on an RPi3+ ... by using just the script or with help of raspi-conf ?
does that means my script still isn't working for RPi3 correctly, even not with the changes i made yeaterday, and the built-in bluetooth interface still has to be disabled via raspi-conf?

can you please provide your config.txt file

mitchsfm commented
beta-tester commented

so i can keep my script as it is - but for safety i added a commen to the README file.

thank you for reporting, testing and giving feedback.

mitchsfm commented
mitchsfm commented
beta-tester commented

ok,
the script creates a config.txt file that has conditional parts for different RPis.i forgot to add a conditional part for RPi0 then.

#this i have
[pi3]
dtoverlay=pi3-disable-bt

#this i forgot
[pi0]
dtoverlay=pi3-disable-bt

[all]
...

better, i set this option for all RPi's, even for RPi1 and RPi2... i think it will not produce any conflicts if no built-in bluetooth interface is available there.

thank you very much for testing...