Pin A0 mapping

[matthias-bs]

A0 can be connected to VB on the FireBeetle ESP32 board (if R10 and R11 are assembled), but it is also connected to the external input J5.1 via a voltage divider.
To be able to use both ADC input sources independently, the analog inputs of the LoRaWAN_Node PCB should be changed from A0...3 to A1...4.