cancel
Showing results for 
Search instead for 
Did you mean: 

How can I interface an electret microphone (condenser) to STM32F4?

DElec.1
Associate II

I want to interface two electret microphones (stereo sound) to STM32F446 chip. I don't know how to connect it or what protocol or pins I have to use. I have found a lot of information about digital microphones but nothing on this topic.

Thanks.

This discussion is locked. Please start a new topic to ask your question.
24 REPLIES 24

@Andrew Neil​ 

No, it is not an school assignment. The requierement of the use of that model is set by the company.

I am using this model of electret microphone (which meets all the freq requirements 20-20kHz): https://www.digikey.es/es/products/detail/pui-audio-inc/AOM-5024L-HD-F-R/12152286

Having capture the sounds I just will keep them in a memory. The natural sounds I want to detect are birds and mammals (humans too) (nothing about bats and ultrasounds).

I don't have any specifications about sampling (by Nyquist would be 40 kHz), number of bits or anything. In fact, I am a bit lost on this topic of sound. I just want to record sounds in a good quality. All the specifications of that electret mic are good for me.

I am considering connecting it to ADCs and manage to set the "stereo" effect in the firmware o connecting it to au audio codec (but this is what we have talked about; specifications, function and all that).

I am glad there are so many people interested on this topic and helping the community. I say sorry in advanced if any question is too basic.

Thank for your time.

By the way, @Andrew Neil​ 

I have found this preamp to that mic model. It meets the impedance requirement and the voltage one too.

I know in the industry of music, preamps are use to achieve the line level to record. would it be neccesary to preamp this mic before connecting to the ADC? I guess so...

https://www.mouser.es/ProductDetail/Texas-Instruments/LMV1012UP-20-NOPB?qs=7lkVKPoqpbac82UrMPr1hA%3D%3D

"if you are serious about recording stuff. Get yourself a high-quality commercial audio recorder"

Even a low-cost commercial recorder will give better results than anything using cheap electrets...

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

"The requierement of the use of that model is set by the company"

Your employer?

"I am a bit lost on this topic of sound"

Then you should really be speaking to your employer about getting some proper support and/or training in this - if it's part of your job.

"would it be neccesary to preamp this mic before connecting to the ADC?"

Again, as for *any* interfacing problem:

  1. look at the output specs of the microphone;
  2. look at the input specs of the ADC;
  3. If they match, you're good to go; if they don't, you'll need something that makes up for the difference(s).

Almost certainly, a preamp will be required.

"I have found this preamp"

As for any component, Take a look at the support materials available on the manufacturer's website:

0693W00000Nqe3QQAR.png

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Yes, my employer.

Thank you.