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DFSD with two PDM mics using a single input

NKara.3
Associate II

Hi,

I followed the example for DFSDM found in DM00380469_ENV1.pdf and setup the channels as specified (channel 0/1 -> input from ch1 and internal clock). Cube MX also creates 2 pins , CLK and DATAIN1.

STM32F413 MCU

It seems that I cant get any data coming for the second channel it all filter 1 that is attached to channel 1 has no audio although the interrupt is triggered.

The mics are setup for L/R and I can data coming when I connect them one by one to the DATAIN1 pin but when both are connected only one channel has audio.

It's really difficult to see whats happening even if I capture the data from a logic analyser.

Not sure if its a software or hardware issue.

Any advise on how to proceed?

3 REPLIES 3
NKara.3
Associate II

Also it seems that data appears to be the same in both DMA buffers.

NKara.3
Associate II

Hi,

Anyone know how/why the DMA interrupt isnt triggering when using the option to sync with filter 0?

0693W00000FBZiFQAX.png

NKara.3
Associate II

Need to call filter 1 before filter 0.