High Power Consumption - System On

[Roiger]

Hi,
We are currently migrating our nrf5 SDK code to NCS (2.2.0 currently) on a custom nrf52833 board.

While in system off we have been able to achieve our expected sub-uA average consumption (between 0.5 and 0.8), we have been unable to reach our system on value of 3.3 uA, and are stuck on around 5.8 uA average.

Our overlay fragment is below:

&uart0 {
	status = "disabled";
};


&pinctrl {

    // acc
    status = "okay";
    spi1_default: spi1_default {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 4)>,
                <NRF_PSEL(SPIM_MOSI, 0, 11)>,
                <NRF_PSEL(SPIM_MISO, 1, 9)>;
        };
    };

    spi1_sleep: spi1_sleep {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 4)>,
                <NRF_PSEL(SPIM_MOSI, 0, 11)>,
                <NRF_PSEL(SPIM_MISO, 1, 9)>;
                
            low-power-enable;
        };
    };
};


&spi1 {
    compatible = "nordic,nrf-spi";
    status = "okay";
    clock-frequency = <0x4000000>;
    overrun-character = < 255 >;
    cs-gpios = < &gpio0 5 GPIO_ACTIVE_LOW >, < &gpio0 15 GPIO_ACTIVE_LOW >;
};

&spi0 {
    status = "disabled";
};

&adc {
	status="okay";
	compatible = "nordic,nrf-saadc";
	#io-channel-cells = <1>;
};

prj.conf:

CONFIG_GPIO=y
CONFIG_BT=y
CONFIG_BT_DEBUG_LOG=n
CONFIG_BT_SMP=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DIS=y
CONFIG_BT_LIM_ADV_TIMEOUT=60
CONFIG_BT_GATT_CLIENT=y
CONFIG_BT_CTLR_CRYPTO=y
CONFIG_BT_HOST_CCM=n
CONFIG_BT_MAX_PAIRED=5

CONFIG_BOOTLOADER_MCUBOOT=y

CONFIG_BT_CTLR_PHY_2M=n
CONFIG_BT_CTLR_PHY_CODED=n

CONFIG_BT_USER_DATA_LEN_UPDATE=n
CONFIG_BT_BUF_ACL_RX_SIZE=251
CONFIG_BT_BUF_ACL_TX_SIZE=251
CONFIG_BT_L2CAP_TX_MTU=247
CONFIG_BT_CTLR_DATA_LENGTH_MAX=251

CONFIG_BT_AUTO_DATA_LEN_UPDATE=y
CONFIG_BT_GAP_AUTO_UPDATE_CONN_PARAMS=y

CONFIG_BT_HCI=y 
CONFIG_BT_CTLR_LE_ENC=n
CONFIG_BT_SMP_SC_ONLY=n

CONFIG_BT_BONDABLE=y
CONFIG_BT_SMP_ENFORCE_MITM=n
CONFIG_BT_SMP_APP_PAIRING_ACCEPT=n

CONFIG_BT_DEBUG_SMP=n

CONFIG_NRFX_RTC2=y

CONFIG_SPI=y
CONFIG_SPI_NRFX=y

CONFIG_NFCT_PINS_AS_GPIOS=y


## in prod - set all below to false
CONFIG_LOG=y
CONFIG_UART_CONSOLE=n
CONFIG_LOG_BACKEND_UART=n
CONFIG_PRINTK=y
CONFIG_LOG_PRINTK=y
CONFIG_STDOUT_CONSOLE=y
CONFIG_RTT_CONSOLE=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_LOG_BACKEND_RTT=y


CONFIG_BT_DIS_FW_REV=y
CONFIG_BT_DIS_FW_REV_STR=""
CONFIG_BT_DIS_HW_REV=y
CONFIG_BT_DIS_HW_REV_STR=""
CONFIG_BT_DIS_MANUF=""
CONFIG_BT_DIS_MODEL="RTOS"
CONFIG_BT_DIS_SERIAL_NUMBER=y
CONFIG_BT_DIS_SERIAL_NUMBER_STR=""
CONFIG_BT_DIS_SETTINGS=y

CONFIG_SETTINGS_RUNTIME=y
CONFIG_SETTINGS_CUSTOM=y
CONFIG_SETTINGS=y
CONFIG_BT_SETTINGS=y

CONFIG_HARDWARE_DEVICE_CS_GENERATOR=y

CONFIG_BT_DIS_PNP=n
CONFIG_BT_BAS=y
CONFIG_BT_HRS=n
CONFIG_BT_ATT_PREPARE_COUNT=40
CONFIG_BT_DEVICE_NAME=""
CONFIG_BT_DEVICE_APPEARANCE=833

CONFIG_ADC=y
CONFIG_ADC_NRFX_SAADC=y
CONFIG_NRFX_SAADC=y
CONFIG_BOARD_ENABLE_DCDC=y

CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_NVS=y
CONFIG_SETTINGS_NVS=y
CONFIG_FLASH_MAP=y
CONFIG_FCB=n

CONFIG_TEMP_NRF5=n
CONFIG_TEMP_NRF5_MPSL=n
CONFIG_UART_NRFX=n
CONFIG_BOOT_BANNER=n

A few things we have tried:

• Turning off logs - no change.
• Turning off all unused peripherals from the original nrf52833dk.dts file in the overlay - no change.
• Setting states of the CPU using PM - all states besides SOFT_OFF yield no change to power consump.

What are we missing?

Thanks!
Roi

[Roiger]

Hi,

1. As said we have tested this - but I will check again to make sure we have not missed anything
2. We were instructed by Nordic personnel to try and stay on the same release we started with for development stage - hence 2.2.0
3. The level is constant - there are not peaks, it is just that the average is 5.8 instead of 3.3, but the graph seems the same shape in both cases

Thanks!

Roi

[Roiger]

Hi,
I have attempted to turn off everything in overlay that was not turned off in build/zephyr/zephyr.dts:

&nvic {
    status = "disabled";
};

&i2c0 {
    status = "disabled";
};

&temp {
    status = "disabled";
};

&gpiote {
    status = "disabled";
};

&timer0 {
    status = "disabled";
};

&timer1 {
    status = "disabled";
};

&timer2 {
    status = "disabled";
};

&timer3 {
    status = "disabled";
};

&timer4 {
    status = "disabled";
};

&rtc0 {
    status = "disabled";
};

&rtc1 {
    status = "disabled";
};

&ecb {
    status = "disabled";
};

&ccm {
    status = "disabled";
};

&egu0 {
    status = "disabled";
};

&egu1 {
    status = "disabled";
};

&egu2 {
    status = "disabled";
};

&egu3 {
    status = "disabled";
};

&egu4 {
    status = "disabled";
};

&egu5 {
    status = "disabled";
};

&pwm0 {
    status = "disabled";
};

&acl {
    status = "disabled";
};

&ppi {
    status = "disabled";
};

&mwu {
    status = "disabled";
};

&usbd {
    status = "disabled";
};

&uart1 {
    status = "disabled";
};

&spi3 {
    status = "disabled";
};

&wdt0 {
    status = "disabled";
};

&rng_hci {
    status = "disabled";
};
&ieee802154{
    status = "disabled";
};

The only things not disabled are:

• FICR
• UICR
• Clock
• Power
• Radio
• SPI1 - since we are using this for 2 peripherals
• ADC - we use this to measure battery every X hours
• RNG
• RTC2 - see above
• GPIO0
• GPIO1
• pinctrl

The average power consumption remains 5.8 uA

Thanks!

Roi

[Roiger]

For reference I have tried NCS 2.4.0 and the power consump even goes up a bit (5.9 uA average)

[Roiger]

Hi,
I thought it best to update that I also tried with a custom_board (as opposed to an overlay on nrf52833dk_nrf52833, and got the same measurements.

[Susheel Nuguru]

I am sorry for late reply, That power consumption does not make sense.Either you have to test this on nRF52833 DK or help me reproduce it at my desk. I do not know any ERRATA that has about 4.5uA of increased current consumption in system off mode on nRF52833.