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Digital Mems Microphone Interface With Stm32F4 Microcontroller


I am need  to interface STM32F407 board with PDM digital mems microphone to Capture the Realtime sound waves through I2S Serial communication. But little bit confusion is there because in I2S communication there are three pin I2S2_ SD,I2S2_ CK,I2S2_ WS. But in my PDM microphone VDD, GND, L/R,CLK,DOUT only there, No WS(Word Select) pin there in my microphone. So, I little bit confusion to interface Microphone Through I2S communication ?.Thank You for advance to clarify my doubt.


L/R is the WS(Word Select) signal, if you use mic , that has a select pin for this and works with standard I2S interface. (You didnt tell, which mic you want to use.)

On other mics, the clock is switching L+R channel and L/R setting hi or lo , is your choice, which mic should be on "L" or "R" channel.

Here the I2S input needs to be switched to PDM mode, because both signals , rising and falling clock, are used to latch the data,

and/or WS not used at all and conversion PDM -> PCM is done in software only.


Read  AN3998 , PDM audio software decoding on STM32 microcontrollers .



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I have to use only one Digital Mems  microphone  in my case . I am know concept of the pin L/R working .But my question is How to connect my Mems Microphone pin to Stm32F407 Discovery board .I have to attach my Mems microphone and Configuration of I2S communication in my STM32 CubeIDE in Below.I am need your full explaination of my doubt. 

see AN3998:



+ which F407 board ?

+ set in Cube the important basic things: debug, HSE/LSE clock or HSI + clock tree !

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