STM32F4 Series a Question About I2S

mdmrl00 · ‎2024-04-25

Hi, I am trying to do an application where I am using 2 PDM output digital MEMS microphones to get a stereo sound from them and then play it. My question is when I select I2S as Full-Duplex Master for STM32F407VG it only has 1 SD pin. Should connect both microphone's SD pins on this pin or what? Can anyone help me about how to connect two microphones to a single I2S peripheral?

Peter BENSCH · ‎2024-04-25

MEMS microphones typically have a pin (called e.g. LR or SEL) whose level L or H defines which channel the respective microphone should be connected to. The I2S data stream also contains a selection bit that controls the switching.

Hope that answers your question?

Regards
/Peter

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Peter BENSCH · ‎2024-04-25

MEMS microphones typically have a pin (called e.g. LR or SEL) whose level L or H defines which channel the respective microphone should be connected to. The I2S data stream also contains a selection bit that controls the switching.

Hope that answers your question?

Regards
/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

mdmrl00 · ‎2024-04-25

Thank you for the answer. But what I really meant was if I pull L/R pin of one microphone to VDD and the other to GND can I connect them to the same I2S peripheral's SD pin?

Peter BENSCH · ‎2024-04-25

Yes, it is exactly the purpose of that pin, to connect two such microphones to one I2S.

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.