NRF52840DK CONFIG_PM not taken into account

[S MOUNZEO]

Hi everyone,

I'm working on a Matter based project on the NRF52840 SoC. Since it's an Iot project project we need to reduce power consumption at it's minium for lifetime purpose. But when entrering sleep System ON, the consumption remain to 0,5 mA wich is far away from the 3µA from the datasheet.

here is a part of Kconfig file

CONFIG_SERIAL=n
CONFIG_PM=y
CONFIG_PM_DEVICE=y

And then in the main I directly enter sleep mode to test and measure the current consumption

#include "app_task.h"
#include <zephyr/logging/log.h>


LOG_MODULE_REGISTER(app, CONFIG_CHIP_APP_LOG_LEVEL);

int main()
{	
	k_msleep(30000);
	CHIP_ERROR err = AppTask::Instance().StartApp();

	LOG_ERR("Exited with code %" CHIP_ERROR_FORMAT, err.Format());
	return err == CHIP_NO_ERROR ? EXIT_SUCCESS : EXIT_FAILURE;
}

Is anyone have a hints to do that correctly ?

[Kazi Afroza Sultana]

Hello,

There would be several reasons for this high current consumption. Do you have some peripheral on the board which are not in use for the application. 

You can try to disable UART peripheral on the overlay file and check the current consumption again?

For example: to disable UARt1 we can write the following code in overlay file

&uart1 {
status = "disabled";
};

[S MOUNZEO]

Hello, thanks for the answer. In my configuration the UART is already disabled

uart1: uart@40028000 {
			compatible = "nordic,nrf-uarte";
			reg = <0x40028000 0x1000>;
			interrupts = <40 NRF_DEFAULT_IRQ_PRIORITY>;
			status = "disabled";
		};

[Kazi Afroza Sultana]

Hello,

Have you checked if any GPIOs pins are floating? I have found one of my old case (+) Can't reach desired μA values on nRF52833 on power saving modes - Nordic Q&A - Nordic DevZone - Nordic DevZone which solved current consumption just checking the GPIO pins.

If this does not work, I may ask you to send the application file so I can check the configuration and coding from my side.

[S MOUNZEO]

Hello,

I solved the problem. I assume that there was someting (the UART, or the console log) that was maintaining the current consumption high.

Thanks