Unable to Build DMIC Sample on nRF5340 Audio DK

RE: Unable to Build DMIC Sample on nRF5340 Audio DK

Anushikha — Thu, 25 Apr 2024 07:20:12 GMT

Thank you for your help. I have created this overlay file which works perfectly for nrf5340 audio DK.

&clock {
	hfclkaudio-frequency = <12288000>;
};

&pinctrl {
	pdm0_default_alt: pdm0_default_alt {
		group1 {
			psels = <NRF_PSEL(PDM_CLK, 0, 14)>,
				<NRF_PSEL(PDM_DIN, 0, 13)>;
		};
	};
};

dmic_dev: &pdm0 {
	status = "okay";
	pinctrl-0 = <&pdm0_default_alt>;
	pinctrl-names = "default";
	clock-source = "ACLK";
};

This Dmic sample gives the following output-

I am attaching the dmic sample which works for the nrf5340 audio DK.
SDK version- 2.5.2
toolchain version- 2.5.2

devzone.nordicsemi.com/.../3857.dmic.zip

RE: Unable to Build DMIC Sample on nRF5340 Audio DK

Menon — Fri, 02 Feb 2024 09:51:04 GMT

Hello,

Please see the requirement section: https://github.com/nrfconnect/sdk-zephyr/tree/main/samples/drivers/audio/dmic#:~:text=received%20audio%20data.-,Requirements,-The%20device%20to

Kind Regards,

Abhijith

RE: Unable to Build DMIC Sample on nRF5340 Audio DK

Ladivin — Fri, 02 Feb 2024 08:32:00 GMT

Hi Anushikha,

I'm not from Nordic, but I believe I understand the problem so I dare to answer this question.

This Zephyr sample works out of the box only for nRF52840 DK and nRF5340 DK (i.e. not for nRF5340 Audio DK). To make it up and running for the audio kit, you need to create a device tree overlay that specifies `dmic_dev` node. You can have a look into `boards` folder which is present in the sample. There you can get some inspiration how this is done for the two supported devkits.

One more note - the DMIC sample probably won't work with the microphone which is present on the audio devkit. This microphone is not connected directly to the nRF5340 SoC but it goes through the HW codec and the HW codec is connected via I2S interface. So the `pdm` related API used in the sample couldn't be used here.

So the bottom line is, unless you want to use an external microphone, this sample is not suitable for nRF5340 Audio DK anyway.

Hope this helps.

And of course, if I'm wrong, Nordic guys, please shout :)

Thanks,

Ladivin