I am wondering if I could edit the firmware-basic provided in the GitHub repository to run a light-weight algorithm on the real-time audio data and store the output on the SD card.
Is there any good way to understand the flow of the firmware/any documentation in detail? It would be really helpful if I could get some pointers for it.
Thanks for information, Andy! I will check those out.
Firmware-basic has a Wiki description, however, if you wanted to write your own firmware a better place to start is the AudioMoth-Project. The Wiki for this describes getting started a little better.