High Idle Current Consumption nRF52833 DK

[jansens]

Hi, using the Nordic power profiler 2 (PP2) kit to measure the current draw of my nRF52833 DK. I have followed the instructions to setup/prepare/wire the PP2 to my DK and current measurement appears to be working correctly.

My issue is that my idle current is around 450 uA when running a simple hello world program which should just let the CPU idle once it has run. I'll include my code and files. My question is, what am I doing wrong that I see such a high system idle current?

This is how it is wired up:

nRF Power Source Switch = VDD (button/coin battery is installed)

USB is connected to DK (as seen above) for UART debug/output

Using nRF Connect SDK v1.5.1 with Zephyr.

Do I need to set "CONFIG_SERIAL=n" in the prf.conf to see accurate power readings? I realize I won't be able to see my output via UART console but I believe this is what is causing the high current consumption.

Ideally I would like to be able to see my power output and my console output at the same time but if this isn't possible I can work around it.

Best,
Sam

[jansens]

Ok so setting CONFIG_SERIAL=n brought me down to about 8 uA which is around where I expected.

[Karl Ylvisaker]

Hello Sam,

I am happy to hear that you were able to bring the current down to the expected levels! :)
The UART logging is indeed known to increase power consumption by quite a lot. The RTT option has a lower power consumption than the UART, but still it will throw off your readings.

Please do not hesitate to open another ticket if you encounter any issues or questions in the future.

Good luck with your development!

Best regards,
Karl