PDM Microphone via DMIC Interface

Hi, I have read: PDM Microphone via DMIC Interface to get some inspiration but on NX it seems to be different. I cannot see any DMIC1 in pinmux while alsamixer controls for DMIC1 exists. DO we need to add proper pinmux in dts for DMIC1 or how it should be intialized? Thanks.

Hi marek.belisko,

Is this still an issue to support?


yes I still didn’t find proper way how to solve it. Thanks.


The audio interfaces for all boards are listed here. For NX you have a few choices; you can use DMIC1/2 via the M.2 connector or DMIC4 via the 40-pin header. DMIC4 is a bit easier to access and the pinmux can be configured using the jetson-io tool.


Hi @jonathanh, we have custom breakboard for NX SOM and we’r etrying to configure DMIC1 on ping 222 and 224 similar like described in this topic: PDM Microphone via DMIC Interface

I checked pinmux :

 sudo cat /sys/kernel/debug/pinctrl/2430000.pinmux/pinconf-groups | grep -i dmic

but it return no value for dmic at all and also:

cat /sys/firmware/devicetree/base/pinmux@2430000

doesn’t contain any info about dmic. We’re running Ubuntu and I’m not sure what needs t obe configured in order to have dmic microphone working. Thanks.


The DMIC1 pins are available on the DAP3 pins and so yes you will not see any reference to DMIC1 in the pinmux unless the DAP3 are muxed to the DMIC1 pins.

To reconfigure the DAP3 pins you need to use the pinmux spreadsheet for NX and there are some high-level details here.