Problems with PPS on a Pi0w running raspian and attached to a BerryGPS-IMUv3

[ray]

Howdy,

I am knew to GPS , and attached a BerryGPS-IMUv3 to my pi 0 w.  I soldiered t T_PULSE ping to GPIO18 on my PI.  I updated /boot/config.txt with dtoverlay=pps-gpio,gpiopin=18 and loaded the pps-gpio module.

GPS parts seem to be working great, but i cant get any PPS info in gpsmon, and trying ppstest /dev/pps0 doesnt seem to work.  I do not have direct line of sight to the sky at the moment, and using internal antenna. My soldier job looks good.  I googled around to see if i had to do anything else.  I tried adding /dev/pps0 to gpsd config, but nothing changed.  GPSD seems to create a /dev/pps1 , but get same error from ppstest.

Any ideas what could be wrong or some advice/docs?

Thanks for any help.

Ray

—-

ppstest:

root@raspberrypi:/boot# ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
time_pps_fetch() error -1 (Connection timed out)

pps dmesg:

root@raspberrypi:/boot# dmesg -T | grep pps
[Sun Apr 7 17:31:53 2019] pps_core: LinuxPPS API ver. 1 registered
[Sun Apr 7 17:31:53 2019] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[Sun Apr 7 17:31:53 2019] pps pps0: new PPS source pps@12.-1
[Sun Apr 7 17:31:53 2019] pps pps0: Registered IRQ 163 as PPS source
[Sun Apr 7 17:33:25 2019] pps_ldisc: PPS line discipline registered
[Sun Apr 7 17:33:25 2019] pps pps1: new PPS source serial0
[Sun Apr 7 17:33:25 2019] pps pps1: source "/dev/ttyS0" added
[Sun Apr 7 17:41:41 2019] pps pps1: removed
[Sun Apr 7 17:41:41 2019] pps pps1: new PPS source serial0
[Sun Apr 7 17:41:41 2019] pps pps1: source "/dev/ttyS0" added
[Sun Apr 7 17:41:57 2019] pps pps1: removed
[Sun Apr 7 17:41:57 2019] pps pps1: new PPS source serial0
[Sun Apr 7 17:41:57 2019] pps pps1: source "/dev/ttyS0" added

gpsmon:

tcp://localhost:2947 JSON slave driver> u-blox requires 80x20 screen
(84) {"class":"VERSION","release":"3.16","rev":"3.16-4","proto_major":3,"proto_minor":11}
(384) {"class":"DEVICES","devices":[{"class":"DEVICE","path":"/dev/serial0","driver":"u-blox","subtype":"SW ROM CORE 3.01 (107888),HW 00080000,FW
VER=SPG 3.01,PROTVER=18","activated":"2019-04-07T22:42:36.306Z","flags":1,"native":1,"bps":9600,"parity":"N","stopbits":1,"cycle":1.00,"mincycle"
:0.25},{"class":"DEVICE","path":"/dev/pps0","driver":"PPS","activated":"2019-04-07T22:41:57.907Z"}]}
(122) {"class":"WATCH","enable":true,"json":false,"nmea":false,"raw":2,"scaled":false,"timing":false,"split24":false,"pps":true}

[Mark Williams]

I have never see any information in the PPS field.   I also see this in the man documentation;

BUGS AND LIMITATIONS
The PPS Offset field will never be updated when running in client mode, even if you can see PPS events in the packet window. This limitation may be fixed in a future
release.

Regarding PPS test, I was able to get it working right away;

1.  Cabled up GPIO18 (Physical  pin 12) to TP pin on GPS
2. added dtoverlay=pps-gpio,gpiopin=18  to config.txt
3. rebooted

 

pi@raspberrypi:~ $ 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 1554704895.005692570, sequence: 320 - clear 0.000000000, sequence: 0
source 0 - assert 1554704896.005720448, sequence: 321 - clear 0.000000000, sequence: 0
source 0 - assert 1554704897.005717314, sequence: 322 - clear 0.000000000, sequence: 0
source 0 - assert 1554704898.005742168, sequence: 323 - clear 0.000000000, sequence: 0

 

Are you using GPIO18 for anything else?

Mark --OzzMaker.com --

[ray]

Nope nothing else on the pin.  However, It magically started working tonight.  I powered it off to attach an external antenna , powered it on, and every thing started right up and worked.   Even with the switch set to ext antenna, powered it off, removed antenna, still working.

 

Im just going to chalk it up to human error on my part.

Thanks for the help though.

[Author]

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