First off, thanks to the AudioMoth team for such a wonderful device, you've made quite an impact for the future of conservation work. Well done.
I am trying to put together a custom firmware to stream out the audio data via the TX/RX pins on the unpopulated header on the top. Quoting Alex Rogers from this post: https://www.openacousticdevices.info/support/device-support/audiomoth-schematics
"There is an unpopulated header on the the top of the AudioMoth that is connected to GND, 3V3 and four GPIO pins. This is the easiest way to connect additional sensors or an external radio module."
Digging deeper, I see that you are using a SiLabs EFM32WG980F256-QFP100. Looking at the datasheet, I see there are several UARTs:
So, my question(s) are:
What UART is connected to these pins (3 & 4)? I do not have EAGLE and couldn't find on my own what MCU pins you have tied to these points. I am assuming it's the LEUART.
Are there any facilities in the AudioMoth library to use said UART, or would it be purely the SiLabs SDK to get this to work?
Thanks in advance.