Cellular IoT App Shield - GPS

I’m working with the GNSS on the Cellular IoT App Shield and wanted to share a few lessons learned with the community:

-I updated the firmware for the BG96 module (mine was BG96-MA-XXX-XXX version). I had trouble installing the driver using a long USB cable connected to the Cellular IoT App Shield since my PC was not recognizing the board even though it was connected and powered on. I found that using the short 90-degree USB connector between the PC and board allowed it to be recognized immediately and the driver installation completed without issue (although the Quectel flash tool switched the DM COM port from what was established initially, but using Device Manager I was able to identify the new DM COM port and updated the flash tool parameter accordingly).
-For a long time I was receiving error 516 (no satellite fix) on the AT+QGPSLOC? command even after hours of sitting outside with clear view of sky and an active antenna connected to GNSS antenna plug. I was unable to receive position information using the Internal Active GPS Patch Antenna – 15dB – 25mm x 25mm – u.FL Plug antenna (as well as with another active GPS antenna that I have). At my wits end I connected the LTE Antenna SMA – 3dBi that I have and within seconds I had a fix. @sixfab Is this expected behavior?
-I’ve been using Minicom on /dev/ttyUSB2 to send GNSS AT commands with the module, and this works well.
-While connected to Mincom on USB2, I open a second Minicom terminal on /dev/ttyUSB1 to view the nmea sentences and troubleshoot.
-Following another tutorial (“how-to-use-3g-and-gps-on-raspberry-pi-with-thaieasyelec-3g-hat-expansion-board”) I installed the gpsd package, and was able to monitor formatted nmea outputs using gpsmon /dev/ttyUSB1 and this works very well. However, I have not been able to get the cgps client to work.

It would be nice to see some more documentation on the GNSS side of the BG96 module, so hopefully this helps other users as they explore.

Hi @c_c_h,
Thank you for your feedback. Generally GNSS doesn’t need cellular connection. Mention the previous and present firmware version, please?

@ensar, the current BG96 firmware: BG96MAR02A10M1G
I don’t think I kept track of the previous firmware version.

My question above is regarding what type of antenna works best for the GNSS module? I know that the GNSS operates without a cellular connection. My issue is that I was not receiving GNSS signals when I used the GPS antennas (plugged into the GNSS antenna socket). However, when I plugged a cellular antenna into the GNSS antenna socket, the GNSS data showed up almost immediately (whereas the NMEA sentences were mostly empty with the GNSS antenna plugged into the GNSS antenna socket).

I guess my issue has been resolved since the GNSS is up and running with the LTE-SMA-3dbi antenna plugged into the GNSS socket. I also use a second LTE antenna plugged into the LTE antenna socket and both cellular and GNSS communication work fine.