I am using the Arduino Nano 33 BLE Sense (with nRF52840) which comes with a mounted MEMS PDM microphone (MP34DT05). My project will be battery powered and thus calls for me to put the MCU into low power mode when appropriate. So, what I would like to do is use the mic as a sound detector that wakes the nRF52840 when it detects a sound at a volume past some threshold. The +V to the microphone is delivered via QSPICS/GPIO51 and the microphone output is connected to GPIO7 and the clock to GPIO42.
From my understanding I cannot use the DETECT signal as this is only triggered when it detects a change in one of the GPIO pins, and the mic output should be swinging high to low constantly regardless of volume (due to the nature of PDM). I do think it might be possible to use the ANADETECT signal by tapping off of the microphone output and running that through a low pass filter (PDM through a low pass filter gives the analog waveform) and hooking that back up to an analog pin to be used with ANADETECT. If this is a viable option, is there a way to short GPIO pins in software so that I don't have to actually solder a wire to the output of the mic and I can just read the mic output from some other GPIO pin?
Also, maybe there is some sort of PDM interrupt that I could use that I have not yet come across?
I'm really not sure if this is possible or if there are other ways to go about doing this, so some help would be greatly appreciated! Also, I hope I was clear enough in the description of my problem, and if not would be happy to provide more.
