energy peak every 166 ms in sleep mode

RE: energy peak every 166 ms in sleep mode

Stian Røed Hafskjold — Wed, 17 Jul 2019 12:52:20 GMT

Hi, this is refresh spikes. If you search for "refresh spikes" or "refresh mode" here on Devzone you will find posts describing this with plots etc. Short story: This is as expected and the current including the spikes is supposed to be 0.3uA in system OFF mode.

The button is not polled.

Compiling code as "debug" is not the same as entering "debug mode". The emulated system OFF is when you have the debugger attached to the board and are actually debugging the chip.

RE: energy peak every 166 ms in sleep mode

Kolonka — Tue, 16 Jul 2019 20:20:08 GMT

I am sure, the device is not advertising :) the blue voltage is measured between a 10 kohm resistor (the device works correctly with that resistor. i am raising the resistor on-the-fly after the device is in low power mode, so the mpu never get less then 2 volts). the average voltage of 15.36 mV correspondents to 1.5 uA.

I also got measurements from advertising. average current is 762 uA over there. in advertising there is also an led blinking every 2 seconds which raises that a bit. the peaks in advertising are actually in the same interval as in idle but smaller.

in idle the peaks are about 20 uA. in advertising the peaks are 11 mA if i see correctly.

the interval is somewhere about 1/5s or 1/6s, which is 166ms to 200ms. could it be that the timer from advertising is waking up the mpu but the mpu is just ignoring it and going back to sleep.

i cant upload the image. it says 'cant load preview'

RE: energy peak every 166 ms in sleep mode

sewes — Tue, 16 Jul 2019 19:58:10 GMT

Are these the first seconds after the startup or is it after 3 minutes when the nrf52 goes into system off mode?

Usually the button is interrupt-based and the application doesn't need to poll it.

Maybe your 166ms are actually 187.5ms and your device sends advertisements.

187.5ms is the default value for the advertisement intervall in the ble_template. :-)