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STM32F407G discovery


i have an SPH18R1LM4H-1 audio sensor developed by Knowles company,  you can also check this on their site and datasheet. it needs an clock frequency of 2.4Mhz. Means when we input the clock frequency , the audio sensor then generate an data according to human voice. This SPH18R1LM4H-1 have four pins. data pin, clock pin, power supply pin and select pin which is NOT connected when you used single sensor. This sensor have DAC which internally converts the analog signal to digital signal. i want to read that digital signal with the help of STM32F407G board. This SPH18R1LM4H-1 is PDM microphone. how i can do that ? please explain in details and along with code would be beneficial for me. 

According to me, first we have to input the clock frequency of 2.4MHZ to SPH18R1LM4H-1 with the help of any Gpio pin of STM32F407G board. Then second task is to read that data coming from SPH18R1LM4H-1. I need an code also along with yours Guidance. or steps for this. 

Actually PDM library is best of PDM microphone, but it works on only Arduino nano 33 and Xiao Rf2040 module. I have ESP32 WROOM Da module and STM32F407G board.

for that easy, i am using Arduino Ide which i have set the settings already. 

Thanks in Advance. or we can connect personally for this...!!!!!



Karl Yamashita
Lead II

Just did a Google search and there are many resources to learn from. Here are the first two that show up.




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Hi Karl, Thank you so much for the reply, Actually I have watched this video already that you shared. but I want an , how SPH18R1LM4H-1 PDM audio sensor is interface with stm32f407g discovery board. As i am newbie. So, i have not too much knowledge,  Actually, when we provide an external clock frequency of 2.4MHZ to SPH18R1LM4H-1 PDM sensor, it gives us the PDM output data, Later we need to convert PDM TO PCM to readable form. so, please can you guide me ? how i can do this. Step by Step. It would be great for me. How pdm to pcm ? 


Harsh Kumar