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

[Susheel Nuguru]

What is the main application doing? Since you achieved lower currents in nRF5SDK, it most likely is a configuration issue rather than any hw/sw issue.

But it is hard for me to narrow down the problem with the information given. Can you please provide me the whole application project so that I can try to debug that here?

Also there might be little more overhead in kernel tick handling which might consume little more power than the bate metal examples. I have not benchmarked how much more but should be that big difference like you are observing.

[Roiger]

Hi,
I cannot upload the code itself, but I can outline what is running when I measure these levels:

• Within main loop:
  
  • Checking boolean flags - in 99% of the cases the work portion does not happen:
    

    			if(flag1 || flag2 || flag3){
    				//work
    			}

  • k_msleep(100);
• Async during main loop:
  • Two buttons awaiting interrupts - awaiting on GPIO_INT_LEVEL_ACTIVE
  • Single shot timer is running, and is restarted every minute:
    

    //definition
    K_TIMER_DEFINE(sleep_timer, sleep_timer_elapsed, sleep_timer_stopped);
    
    // start logic
    k_timer_start(&sleep_timer, K_MINUTES(1), K_NO_WAIT);

  • RTC2 is running with 511 prescaler:
    

    const nrfx_rtc_t rtc = NRFX_RTC_INSTANCE(2);
    
        int ret;
        nrfx_rtc_config_t config = {.prescaler = SYS_TIME_PRESCALER, .reliable = false, .tick_latency = 1,
                                    .interrupt_priority = NRFX_RTC_DEFAULT_CONFIG_IRQ_PRIORITY};
    
    
        ret = nrfx_rtc_init(&rtc, &config, rtc_handler);
        	if (ret < 0) {
    		return;
    	}
    	nrfx_rtc_tick_enable(&rtc, true);
        nrfx_rtc_overflow_enable(&rtc, true);
        nrfx_rtc_tick_disable(&rtc);
        nrfx_rtc_enable(&rtc);

Thanks!

Roi

[Susheel Nuguru]

Hmm,

I do not see your flags handling and I assume that you handle them well without introducing any race conditions.

You seems to need dedicated instance of RTC peripheral (RTC2), can't you use the RTOS timing features instead of having a dedicated RTC in this case?

Regarding below

	nrfx_rtc_tick_enable(&rtc, true);
    nrfx_rtc_overflow_enable(&rtc, true);
    nrfx_rtc_tick_disable(&rtc);
    nrfx_rtc_enable(&rtc);

Why do you enable and disable the tick immediately?

What is the current you observe without initializing this addtional RTC(2) instance?

[Roiger]

Hi,

• What are you referring to when you mean RTOS timing?
• regarding the disable - this is how it was on nrf5SDK - I can try without
• I have tried without the RTC(2) instance as well as turning off in prj.conf - the same level (5.8 uA average) occurrs.

Thanks!

Roi

[Susheel Nuguru]

The only things I can think about with the info you provided is

1. Some peripheral might still be enabled. You can check the build\zephyr\zephyr.dts to see if there are any other peripheral that are kept enabled which were not enabled in nRF5SDK.
2. maybe some errata workaround is missing that you applied in nRF5SDK? We have released NCSv2.4.0 which is more latest. When you are already putting efforts to move from nRF5SDK to NCS, why not move to the latest?
3. can you connect the power profiler to the app based on nRF5SDK and the app based on NCS and see where the difference in power consumption happens? Do you see any particular spikes or increased current or the increased power is constant over time? It will help us understand the nature of the increase and hence might help us narrow down this to a peripheral that consumes the extra power.

[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)