stm32f4discovery and hardware microphone

[angy89]

Hello!
i've started embedded programming a few days ago when my robotics and embedded programming professor gave me a STM32F4Discovery board that I will ha to use for an embedded project involving the audio capabilities of this board.
I'm starting to figure out all the components of chibiOS but I'm having troubles figuring out what are the steps for using the internal hardware microphone with the ADC.
So what I have to do in order to capture audio from the mic convert it in digital in order to process the data?
thanks for your help

[Giovanni]

Hi,

The microphone has a PDM output (Pulse Density Modulation if I remember well), ChibiOS does not have a driver for that but on the ST web site there should be a library for the F4 that does that, you may consider using that library as-is (feasibility is to be assessed) or port the code under ChibiOS somehow.

Start reading the datasheet of the microphone, then examine the ST library in order to understand how it is done.

Giovanni

[Tectu]

And in case of you should ever have to sample an analog microphone, there's a module providing a high level API for that in ChibiOS/GFX.


~ Tectu