During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Edvin — Wed, 17 Sep 2025 12:18:17 GMT

Can you please upload the application that you are using so that I can try to reproduce the numbers that you are seeing? Will it work without a microphone connected? Or do I need a physical microphone as well?

Best regards,

Edvin

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Adityanath Pandey — Fri, 12 Sep 2025 05:26:37 GMT

I have referred to this link : https://docs.nordicsemi.com/bundle/ps_nrf5340/page/chapters/current_consumption/doc/current_consumption.html

I am not using PPK2 kit but using DMM6500 (6 1/2 Digital multi meter ) for measuring current.

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Edvin — Thu, 11 Sep 2025 19:57:43 GMT

[quote user="Adityanath Pandey"]PDM peripheral should consume only about 1.25 mA[/quote]

Can you point me to where it says? I couldn't find it.

However, it is possible that this number is for the PDM only, not including the current for the HFXO running, and the CPU running to handle the incoming data.

How do you measure the current consumption, by they way? Are you using the PPK2?

Best regards,

Edvin

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Adityanath Pandey — Thu, 11 Sep 2025 05:25:02 GMT

However, according to the nRF5340 datasheet, the PDM peripheral should consume only about 1.25 mA.so current with easyDma?

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Adityanath Pandey — Thu, 11 Sep 2025 05:23:50 GMT

I have created one thread from where mic::readdata() has been called.

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Edvin — Wed, 10 Sep 2025 20:20:37 GMT

And from where are you calling mic::readdata()?

Best regards,

Edvin

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Adityanath Pandey — Mon, 08 Sep 2025 11:58:03 GMT

We are not calling dmic_trigger() from an interrupt.

We use it in our application code, before and after reading data. The actual microphone data is obtained through the dmic_read() API.
Our read function looks like this:
int mic::readdata(void *pcm_data, uint16_t *len) { int ret; void *buffer; uint32_t size = 0; ret = dmic_read(dmic, 0, &buffer, &size, READ_TIMEOUT); if (ret < 0) { LOG_ERR("read failed: %d", ret); return ret; } memcpy(pcm_data, buffer, size); *len = size; k_mem_slab_free(&mem_slab, buffer); return ret; }

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Edvin — Mon, 08 Sep 2025 11:41:17 GMT

From where do you call dmic_trigger()? In an interrupt? And what sort of buffer are you using? Single? Double?

Best regards,

Edvin

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Adityanath Pandey — Fri, 05 Sep 2025 13:31:58 GMT

We read microphone data by calling dmic_trigger(dmic, DMIC_TRIGGER_START) before starting,

and dmic_trigger(dmic, DMIC_TRIGGER_STOP) afterward. This process is repeated every 100 ms.
However, when we parse the recorded file, we hear a “beep” sound.

My question: How long does dmic_trigger() take to execute, and could this delay be the cause of the beep sound?

RE: During mono audio capture over PDM, we observed a current draw of about 1.5 mA.

Turbo J — Wed, 03 Sep 2025 14:15:33 GMT

Expected behaviour.

You need to keep the HF clocks running in order to be able to capture the audio data. That keeps a fairly sizeable portion of the digital chip area powered on and not being able to sleep at all.