NRF5340 PDM (dmic) unresponsive

RE: NRF5340 PDM (dmic) unresponsive

Kazi Afroza Sultana — Thu, 06 Jun 2024 11:28:13 GMT

Hello,

What is the update of your project now?

Can you please try to test with an oscilloscope to see there is any change in the output of the microphone when this happens?

RE: NRF5340 PDM (dmic) unresponsive

pauleffect — Tue, 19 Mar 2024 04:14:27 GMT

it isnt.

I reworked my project, as prev. stated, kept it at a bare minimum. eventually (though i have no clue what i did) it started working at all sampling rates 16 through 48khz. made a backup. continued to work on the project, without touching the dmic handler. stopped working when retried recording (again 7 7 7 7).

erased the product. reflashed the backup. working audio.

erased the product. reflashed the most recent build. no audio.

erased the product. reflashed the backup. no audio.

it's mind boggling.

RE: NRF5340 PDM (dmic) unresponsive

responsible_duck — Tue, 19 Mar 2024 04:10:50 GMT

We are also having issues running our stereo PDM mic configuration at 48 kHz. We could only go up to 24 kHz. We even tried a mono PDM mic configuration and it still didn't output anything usable until we went back down to 24 kHz. I wonder if there is some buried driver limitation on this?

RE: NRF5340 PDM (dmic) unresponsive

pauleffect — Sat, 16 Mar 2024 04:23:04 GMT

I did. I did eventually manage to get it working and I backed up the project (old school zip). Lets call this version A.

Continued to implement things, and again, not working (with the dmic driver untouched). Again 7, 7, 7, 7. Lets call this version B.

Unpacked the backup, burned it again, dmic working.

Flashed version A, dmic was working. Flashed B, not working. Flashed A again, not working. This is infuriating and incredibly hard to debug. Actually, next to impossible.

I ended up redesigning the project entirely - going the I2S route.

RE: NRF5340 PDM (dmic) unresponsive

Kazi Afroza Sultana — Sun, 10 Mar 2024 10:42:05 GMT

Did you try eraseall or recover command?

RE: NRF5340 PDM (dmic) unresponsive

pauleffect — Thu, 07 Mar 2024 16:10:15 GMT

my NCS version is 2.5.2.

I get output, but most of the time it's just a buffer filled with sevens (i mean the integer value).

Last evening I got audio at 31.25 khz by switching to the 32 Khz clock. Now, the same program, untouched - 7s. Not even a power cycle works.

RE: NRF5340 PDM (dmic) unresponsive

Kazi Afroza Sultana — Thu, 07 Mar 2024 15:20:58 GMT

Hello,

Can you try to use eraseall or recover after each time works if it fixes the issue?

Which version of NCS you are using? I tried the DMIC sample on nRF5340 on NCS v2.5.2.

My output looks like this:

If you are using an older version, then it might be worth to check if you see the same issue on a newer version of NCS.

Thanks.

Kazi