SDK17.1.0 nRF52840 PDM

RE: SDK17.1.0 nRF52840 PDM

sacha23 — Thu, 25 Apr 2024 05:34:17 GMT

Pouya heybatei I am also working on interfacing a PDM microphone with nrf52840. Can you please share your sample code?

RE: SDK17.1.0 nRF52840 PDM

Pouya heybatei — Tue, 13 Feb 2024 10:24:17 GMT

Hi,

I mean at the datasheet of NORDIC it say's "Each bitstream is fed into a digital filter which converts the PDM stream into 16-bit PCM samples" and I can't realize that I should convert it to C language or the NORDIC libraries do this automatically.

RE: SDK17.1.0 nRF52840 PDM

Kenneth — Tue, 13 Feb 2024 10:03:38 GMT

Hello,

I can find that searching online for difference between pcm and pdm provide many relevant results. I suggest to try that first, since I am sure they can cover this better than me.

Kenneth

RE: SDK17.1.0 nRF52840 PDM

Pouya heybatei — Tue, 13 Feb 2024 05:21:34 GMT

thank Kenneth.
today we have PDM data .
can you tell me how to convert PDM to PCM .

RE: SDK17.1.0 nRF52840 PDM

Kenneth — Sun, 04 Feb 2024 16:26:04 GMT

Hello,

Not sure I understand, the PDM peripheral provide a CLK output and have a DATA input (DIN).

If there is no data on the DATA input (DIN), then you need to check your microphone and whether you have powered it correctly, common ground and check that the PDM pin are connected correctly to the microphone. Also make sure you run the CLK for >10ms to ensure that the microphone have time to start to provide data.

Kenneth