Microphones streaming through I2S

[Fib]

Hi,

I'm trying to implement the streaming of two MEMS microphones via I2S.

Following some examples provided by ST, I was able to implement the acquisition of the two microphones: I obtain a 32 samples buffer PCM every 1 ms (left and right channel).

Now I'm trying to send these samples through I2S (16 Bits Data on 16 Bits Frame, 16 KHz) using DMA in circular mode. So, I can fill the buffer while the transmission goes on.

I've created a 128-elements buffer. Every 1 ms I put in the buffer 32 elements. When the buffer contains 64 elements, I launch the transfer using "HAL_I2S_Transmit_DMA".

The problem is that probably the DMA transfer goes slowly compared to the 1 ms filling routine, so what I obtain is that the sound isn't clear.

How can I sync these two operations?

[Eleon BORLINI · Accepted solution]

Hi Fib, could you share some more details of your code? The procedure you are doing is similar the kind of processing of the Bluecoin tool (https://www.st.com/content/st_com/en/products/embedded-software/evaluation-tool-software/stsw-bcnkt01.html:( here there is an example called Audio Loopback that exactly performs what you are wishing to do. Regards

[RFabi.14]

Hello. I have the same problem.

Have you solved your problem ?