Malloc failing when called from firmware

[Larpncohez]

I started by using the guide here to make the Adafruit PDM MEMS breakout function. I would have used the relevant circuitpython library but, from what I have seen, it isn't really meant to work with the pico. If I am wrong about that, it'd be immensely helpful.

GitHub page for this guide is here

After getting the library to compile and function properly, I attempted to make the library accessible through micropython, deciding to opt for rewriting the firmware after struggling with MPY files.

To do this, I used the following forum thread as guidance, replacing the mentioned core1_code with a slight variant of the code in examples/hello_pdm_microphone in the aforementioned GitHub page: forum

After several changes to CMakeLists and a weird series of file transfers, the module imports correctly, and after a lot of debugging I determined a line that seemingly causes the entire MicroPython backend to fail with Thonny being unable to recover the backend unless the pico is fully restarted.

Found on line 50 of src/pdm_microphone.c of the GitHub:

pdm_mic.raw_buffer[i] = malloc(pdm_mic.raw_buffer_size);

Is malloc just not supported when called from the firmware?

[Larpncohez]

In all honesty I am likely just going to order some analog microphones and wire things more directly. This is.... painful, but it would be nice to have clarification in the future

[bidrohini]

You can try the Adafruit CircuitPython library for PDM microphones on the Pico.