Which library should I use for PDM to PCM in STM32L4?

[ALope.1]

Hello everyone,

I'm trying to do the PDM-PCM transformation of MP3DT05 microphone data in a STM32L433RC nucleo board. For my understanding, the better is to use an existing library... But I don't know which one I could use, and I can't even find any practical example.

The application notes available are not helping. I'm receiving the PDM data through HAl_SAI_DMA_receive.

I hope someone can help me find the right way to do this.

Thank you

[Eleon BORLINI]

Hi @ALope.1​ , I would suggest you to start from an existing reference design platform mounting an STM32L4xx device and a digital microphone, equipped with the proper acquisition libraries (via I2S peripheral and PDM-PCM conversion). The reference function pack for ST MEMS microphones is the X-CUBE-MEMSMIC1, and the NUCLEO board closest to STM32L433 could be the STM32L476RG-Nucleo with the digital audio stream acquisition demonstration. You can find the project example in \Projects\STM32L476RG-Nucleo\Demonstration\CCA02M2\Microphones_Streaming. Regards

[Bouraoui Chemli]

Hi @ALope.1​ 

You can refer to PDM library : STM32Cube_FW_L4_V1.15.1\Projects\STM32L4R9I-EVAL\Demonstrations\STemWin\MB1315\Modules\audio_player\Addons\PDM

it may help you to implement your application.

Best regards

Bouraoui