how to capture 8 channels Pdm mic data

[bobhi009]

Hello；

    I saw someone use the  MIXMRT1061DVL6B to capture 8 channels pdm data , but The MIXMRT1061DVL6B have no PDM interface  , how to capture 8 channels PDM mic data ？

[jingpan]

Hi @bobhi009 ,

RT1060 hasn't PDM interface. It can't receive PDM format data by hardware directly. But SAI and PDM has similar waveform. SAI interface can sample PDM data. Then we can convert PDM to PCM by software. You can download SLN-ALEXA-IOT package from https://mcuxpresso.nxp.com/en/select. There is a slnalexaiot_bare_afe demo. It shows how to convert 3 PDM channels to PCM.

Regards,

Jing

[bobhi009]

Thank you, I will download it and study . Also, can you give me some suggestions on how to use AVB？

I want to connect 5 devices in series and synchronize their audio input and output through the network port，  Like the picture show. 

[jingpan · Accepted solution]

Hi,

It's not recommend to add 8 DMIC to RT1060. Because RT1060 hasn't so many SAI. And convert PDM to SAI need lots of CPU bandwidth. 8 DMIC is really too much.

RT1060 SDK hasn't AVB demo. You can download RT1170 SDK. There is AVB demo in it. You can also try to search 'genAVB'. You will find related documents and packages.

Regards,

Jing