Reply To: Raspberry Pi – couple of questions

[Jimbob17]

Yes, that is the script I’m using. The only changes I’ve made is a check to see if the SIM card is present, if it’s not then don’t bother trying to set up the modem to download the AssistNow data because it’s a waste of time. The AT+UPSDA seems to take longer when there is no SIM card in the HAT.

Problem I am seeing with the PPS commands is I cannot start the GPS with the AT+UGPS after I use the AT+UTIMEIND and AT+UTIME commands shown above. First I thought I might need the fully AT+UTIME command as 1,1,1,100 but this makes no difference whatsoever.

This is the output of my python script,

Oct 08 13:12:13 stellarmate systemd[1]: Started Python script for Ozzmaker GPS.
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: Command sent: b’AT+CFUN=0′
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: response b’OK\r\n’
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: Command sent: b’AT+CGDCONT=0,”IP”,”hologram”‘
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: response b’ERROR\r\n’
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: Command sent: b’AT+UTIMEIND=1′
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: response b’OK\r\n’
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: Command sent: b’AT+UTIME=1,1′
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: response b”
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: Command sent: b”
Oct 08 13:12:26 stellarmate ozzmaker-gps.py[1153]: response b’OK\r\n\r\n+UUTIMEIND: 1,0,0,0\r\n\r\n+UUTIMEIND: 4,2,0,0\r\nAT+UGPS=1,4,71\r\r\nERROR\r\n’
Oct 08 13:12:26 stellarmate systemd[1]: ozzmaker.service: Succeeded.

It doesn’t seem to matter what I enter for the AT+UGPS command as all the combinations I’ve tried so far result in the ERROR message. Neither gpsd or cgps show any data coming from the ublox module via /dev/ttyGSM2. The uBlox AT commands bible seems to suggest the PPS pin needs to be setup before trying to use it and I think this is pre-configured already.

Removing the UTIMEIND and UTIME commands results in a working GPS but no PPS sync. For the record, I have the PPS pin setup on the Raspberry Pi to use GPIO18 (previously used with my bog standard GPS modules) and have also tried to use GPIO21 from your example above.

I haven’t tried to solder a blob on JP1 and everytime I want to try a change I have to power everything down and restart. What am I doing wrong? It seems the UUTIMEIND reply above is trying to use the LTE modem, do I need the time commands after I’ve started the GPS messages?