nRF52840 Dongle Matter power optimization

[ady]

Hello,

i'm working on a matter sensor on a nRF52840 Dongle and BME280.

The softaware is based on matter/temperature_sensor with config changes to support nRf52840 Dongle.

Inside config file I have:

CONFIG_PM_DEVICE=y
CONFIG_RAM_POWER_DOWN_LIBRARY=y

CONFIG_LOG=n

and in overlay have disabled: pwm0,uart0,uart1,spi1,spi2,spi3,adc

On PPK2 i have about 35uA ( PPK2 is connected to VBUS and supplying 3,3V to avoid noise from DC/DC converter)

The timer is configured for 30 seconds readings.

I know nRF52840 Dongle is not a supported bord for this kind of app but do you have any suggestions about reducing power even more ? Is this the limit !

I think those 5 sec spikes can be reduced cause send data for 3 sensor readings is done way faster than this.

Does anyone have any suggestion where i should look  / what to change to get better power optimization ?

[Kenneth]

Hello,

Not measure this myself, but you can check out the guides we have:
https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/test_and_optimize/optimizing/power.html 
https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/protocols/matter/getting_started/low_power_configuration.html 

Kenneth

[ady]

Thanks for your answer but i have read all those articles already.

Unfortunately i cannot use CONFIG_SERIAL=n because i'm using I2C.

Another thing that may have an impact might be CONFIG_CHIP_ICD_ACTIVE_MODE_THRESHOLD. This one is set to 5000 ms standard and we also have CONFIG_CHIP_ICD_ACTIVE_MODE_DURATION = 300 ms which goes pretty close to what i'm seeing in ppk2 graph -> those spikes for 5,6 seconds.

I have tried to set CONFIG_CHIP_ICD_ACTIVE_MODE_THRESHOLD to 2500 ms but this just breaks all communication

Please point me to some detailed docs / examples about CONFIG_CHIP_ICD_ACTIVE_MODE_THRESHOLD, CONFIG_CHIP_ICD_ACTIVE_MODE_DURATION that can explain what are they doing.

My sensor should require about 7,2 - 7,3 uA at 2Hz sampling rate but from here to 33 uA there is a lot of space for improvement.

[Kenneth]

CONFIG_SERIAL setting impact UART in this case, no impact to I2C or SPI.

What is the idle current here? Maybe you can even upload the PPK2 trace.

Kenneth