• State Verified Answer
  • Replies 3 replies
  • Subscribers 69 subscribers
  • Views 1085 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 232739
Options
This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

energy peak every 166 ms in sleep mode

Kolonka

hello!

i am using my nrf52832 with s132 softdevice. basically the ble template with my services and charas.

i checked power consumption in sleep mode and observed something interesting. there are energy peaks like 6 times a second. my theory is, that the chip wakes up to check if the wakeup button was clicked. if not, whats happening here? hope its not a misconfiguration.

edit: I got a new theory: the code is compiled in debug mode. in an other thread it says it goes into an 'emulated system off' in that case. I will check tomorrow if it makes a difference, if i compile in release mode. i will update the ticket later

isnt that an average current of 1.5 uA a little bit low? nrf52832 in poweroff and lsm6dsl in sleep should take (0.3 uA to 1.9 uA) + 3uA. actually it will be even lower, if i get rid of the spikes. i did zero-offset the probes before. 15mV should not be that error-prone to measure

Parents
  • 0

    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. :-)

Reply
  • 0

    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. :-)

Children
  • 0 in reply to sewes

    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'

Related