Replace onboard MEMS mic and 3.5 jack for GPIO mic and speaker?

[Lalo91]

Hello. I built a project with STM32F407 DISCO board, I record audio and store it in USB OTG for later playbacks...

 

Anyways, I've been using the onboard MEMS mic as well as the 3.5 audio jack. But I want to replace those for an electret mic and a tiny small speaker connectes through GPIO.

Reason why is I want to use the mic with a long cord/cable. And since it is an onboard mic, ai can't.

It has been a nightmare trying to do this on the last days. It seems easy task for someone who knows the way.

 

Thanks.

 

Ed.

[gregstm]

Not sure what you consider a "long cable", I like digital microphones and I would try the microphone at it's lowest clock frequency (eg. 500KHz ) and maybe add some surface mounts ferrite beads to reduce noise.

But if you want to go to an electret mic, consider buying one of those little boards that have a microphone+amplifier all in one eg. the MAX4466 ( https://www.adafruit.com/product/1063 ) - that way the signal is buffered and will hopefully be less noisy. You could also buy small digital microphone breakout boards to try with your cable.