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Help to connect microphone MEMS IM68A130A to Nucleo H7A3ZI-Q

Dragonmonkey
Associate II

 

Hello to our community,

I'm currently working on connecting a MEMS microphone (IM68A130A) to a Nucleo H7A3ZI-Q microcontroller board. My goal is to record sound with the microphone, send it to MATLAB for processing, and then save and playback the sound.

Could you please assist me with configuring the pins and selecting the appropriate library for this task? I'm new to this area and would greatly appreciate any help you can provide.

Thank you in advance for your support!

1 REPLY 1
tjaekel
Lead

I am working also on PDM (MEMS) MICs (on a STM32U5A5 MCU).

Your MIC (the IM68A130A) seems to be an analogue MIC (there are PDM MICs, I2S MIC and also analogue).

You need an ADC to convert the analogue signal into a digital signal in order to process the audio inside the MCU.

Start with configuring an ADC and sample the data from the MIC (with a reasonable audio sampling rate, e.g. 48KHz). Just to bear in mind: the MCU ADC will be fast enough (e.g. 48 KHz for sampling), but the resolution will be reduced (e.g. just 8..10bits).
Your MIC has 68dB SNR. You need 1bit per 6db. So, 68dB / 6db = 11bits (number of effective bits, NOB). Check, if your MCU ADC has 12bits. If it has just 10bits - fine, just losing some resolution.

A PDM MIC would be already digital, but a different story how to connect to MCU (e.g. via SAI PDM "protocol").