nrf82540 Dongle - reducing consumption during sleep.

RE: nrf82540 Dongle - reducing consumption during sleep.

Hung Bui — Tue, 16 Jun 2026 11:11:09 GMT

Hi,
You are right, using USB for serial log will consume extra current. I believe you can get to lower consumption but if the numbers are good for your development then it's fine.

RE: nrf82540 Dongle - reducing consumption during sleep.

Jarostr — Tue, 16 Jun 2026 10:00:36 GMT

Hello.

Thanks for the answer. I tried k_sleep(). The measured current was the same - 1.6 mA. I tried changing the setting via "nRF Kconfig GUI" - disabling "Board Option / Board uses USB CDC ACM UART as serial backend". I don't know if it is possible to disable / enable this via the program code?

- When using k_sleep() the current dropped to about 25uA.

- When using __WFI the current was 40uA (must be set - irq_disable(RTC1_IRQn).

These values are enough for me for now.

RE: nrf82540 Dongle - reducing consumption during sleep.

Hung Bui — Tue, 16 Jun 2026 07:57:54 GMT

Hi Jaroslav,
Please try testing with our sample in the SDK. Have you used the k_sleep() instead of calling __WFI directly ?
Please also try to test with our BLE sample for example peripheral_hr , the current consumption on average should be at uA level, not mA.

RE: nrf82540 Dongle - reducing consumption during sleep.

Jarostr — Mon, 15 Jun 2026 11:01:56 GMT

Hello. Thanks for the answer. I tried using an empty program using only __WFI - the consumption is the same 1.6mA - measured only with a multimeter (same result on two). I was hoping that if someone had experience how to achieve the lowest consumption on this module and what needs to be set for this. I have a few of these modules and I wanted to use them.

RE: nrf82540 Dongle - reducing consumption during sleep.

Hung Bui — Mon, 15 Jun 2026 09:25:15 GMT

Hi Jaroslav,
I wouldn't suggest to use the nRF52840 dongle as your development platform. It's created as the backend tool for Nordic PC's application (for example nRF Sniffer) .

1.6mA when the CPU is sleeping is indeed high.

Could you let us know how did you do the measurement ? Do you have a power profiller ?

My suggestion is to get hold of a nRF52840 DK or nRF54L15 DK (nRF54 series is our latest chip and is recommended over the nRF52) and do the development on the DK instead.

You can test with some simple application that only put the CPU to sleep (and wake up with RTC to blink an LED for example) to see how low your current consumption is when CPU is put to sleep before you test with GPIO input.