Wrong COM.X UART configuration stops Fire from turning on.
sodoku last edited by
I purchased the COM.X LoRaWAN module for my Fire. The default UART pins are used for PSRAM. Fortunately the COM.X modules have dip switches to change the UART pins, so I changed them to the next group 15/13. Unfortunately this interferes with the LED bar of the M5GO base that comes with the Fire which uses pin 15.
So I switched UART to the last group of pins 0/5. Then my Fire didn't want to turn on. After a bit of research I found that's probably because pin 0 is the boot pin of the ESP32, so the Fire always goes in boot mode.
Now I use the weird setting of ports 13/5, since this is the only option that doesn't interfere with anything else. At least I hope so ..
I think this should be mentioned in the documentation. I am not sure why pin 0 is even an option, since it should be the same issue on any core (1) devices. On core2 pin 0 also doesn't seem to be a good option.