Issue: Having trouble using Bluetooth and GPS module.
Setup: RAK7244C purchased about a month ago from RAKWireless (WisGate Developer D4+ with Cellular module EG95-NA for North America) GPS antenna, Cell main and diversity antenna, and 915MHz LoRa antenna all installed (and confirmed to be working before changing things to get bluetooth to work).
Server: Built-in (with TTN active)
Details: In order to use bluetooth, we’ve changed /root/config.txt: changing dtoverlay from disable-bt to miniuart-bt, and separately enabled hciuart (which does allow bluetooth to work) but this appears to cause ttn-gateway to no longer be able to get valid GPS coordinates even after waiting several hours:
Dec 7 21:55:42 rak-gateway ttn-gateway: # Invalid time reference (age: 1607378082 sec)
Dec 7 21:55:42 rak-gateway ttn-gateway: # no valid GPS coordinates available yet
It will typically get valid GPS coordinates in the first couple of minutes when dtoverlay=disable-bt.
I’m having trouble finding which interface the Ublox Max7 module is actually connected over when dtoverlay=disable-bt (or miniuart-bt), as I get no output from cat /dev/ttyAMA0, while cat /dev/ttyS0 returns “Input/output error”. I understand there are some modifications made on the RAK2245 board made to allow connections to the cellular module to work when the system is ordered together (as a RAK7244C), but I can’t find what those modifications are exactly and which uart (or other comm port - i2c, SPI?) should be in use. I also see that some of the earlier builds of the LoRa/GPS module RAK2245 used an i2c port to connect the GPS to the pi but have instead switched to using a UART on newer builds.
Please let me know which comm channel of the Pi should be connected to the GPS module in this configuration, and any debugging steps that I can try to confirm whether or not they should still work after modifying the dtoverlay to allow bluetooth to work. Maybe there are some different or additional dtoverlays that I need to use in order to allow bluetooth and the GPS to work?