I am looking for a Zephyr expert who can look at my code and analyze why it uses so much power (600uA) for what it does (measure 2 i2c sensors with 10Hz and transmit with 10Hz on BLE). PM if interested!

yes thanks @grobasoz I have, I also have his code here - but it bricked one of my XIAOs, I guess because QSPI is inacessible. Waiting for my JLink to arrive so I can try to save it :smiley: And before that, I’m a bit hesitant to brick even more XIAOs :wink:

[image] here you can see my issue pretty clearly. The big peak at the beginning of each second is expected and okay, the high current for the rest of the second - not so much :frowning:

Yes, JLink is essential for this level of testing. I generally use the “Debug with Ozone” option. I could help you if using a XIAO MG24 but unfortunately my “expertise” doesn’t include the NRF range of devices. I have used them and have a range of devices and development kits but find the developme…

Is the 0.685mA the “average” or “peak” at the time in question? If I get some spare time today I could do some tests on an NRF52840 (non XIAO).

I get about 6uA on an NRF52840 running Zephyr OS which is to be expected I suppose? No QSPI, IMU not enabled, no BLE advertising. Any other “external” devices I should add? Can’t test on a XIAO NRF52840 (don’t have any) - so defer to one of the “experts”. [NRF52840_SleepOff]

So, what I just noticed, the DCDC doesn’t seem to work at all, despite me trying all tricks I know to enable it. Reason why I think this? At 3.7V (on bat pins) I am at 0.65mA, at 2V on same pins I am at 0.3mA What I did is in main() → nrf_power_dcdcen_set(NRF_POWER, true);

0.6mA is the “baseline” in between BLE-events and I2C-sensor-reads

Hi raffiniert, The baseline current value not decreasing may be due to either the device not entering sleep mode or a short Connection Interval. Could you post a baseline current waveform spanning approximately 100 milliseconds?

Hi msfujino of course, thank you so much for chiming in. [image] The connection interval (not the advertising interval, but this problem only matters once connected) is actually 800 ticks = 1000ms, set by the (Arduino) central (but this device is already NCS/Zephyr, as written above): int conn…

The 1mA peak current appears to be doing something approximately every 22ms, likely to maintain the connection. Then, after going to sleep and dropping to zero, it seems to start some task requiring 600uA again. Unfortunately, this is all I can discern at this point; I’m still learning about the nF…

Looking for a Zephyr expert for paid analysis / work

Products & Technology XIAO

msfujino September 3, 2025, 11:07am 24

Thank you for the information.
The link below shows the current data from an experiment where 8 bytes were transferred every 10 seconds. For your reference!