Random ~265uA extra current consuption when NRF52832 is in sleep mode.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Luis — Mon, 29 Apr 2024 20:30:15 GMT

Hello All,

Just to add more information:

Follow a minimal version that will bring the problem:

/**
 * @file main.c
 */

#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "app_timer.h"
#include "nordic_common.h"
#include "nrf.h"
#include "nrf_ble_lesc.h"
#include "nrf_delay.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_sdh.h"
#include "nrf_drv_timer.h"
#include "bsp.h"
#include "app_timer.h"

APP_TIMER_DEF(m_reset_timer_id);

static void reset_timer_handler(void *p_context) {
  sd_nvic_SystemReset();
}

/**
 * @brief Initialize all the required modules and the application layer.
 */
void setup(void)
{

    NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos)|(CLOCK_LFCLKSRC_BYPASS_Enabled << CLOCK_LFCLKSRC_BYPASS_Pos ) |
     (CLOCK_LFCLKSRC_EXTERNAL_Enabled << CLOCK_LFCLKSRC_EXTERNAL_Pos);

    NRF_CLOCK->EVENTS_LFCLKSTARTED = 0; 
    NRF_CLOCK->TASKS_LFCLKSTART = 1;
    while(NRF_CLOCK->EVENTS_LFCLKSTARTED == 0)
    {//do nothing
    }

    nrf_gpio_input_disconnect(BSP_DEF_VBAT_M_PIN);

    // FLASH_CS
    nrf_gpio_cfg_output(BSP_DEF_FLASH_CS_PIN);
    nrf_gpio_pin_write(BSP_DEF_FLASH_CS_PIN, 1);

    // ACCEL_INT
    nrf_gpio_cfg_input(BSP_DEF_ACCEL_INT_PIN, GPIO_PIN_CNF_PULL_Disabled);

    // ACCEL_CS
    nrf_gpio_cfg_output(BSP_DEF_ACCEL_CS_PIN);
    nrf_gpio_pin_write(BSP_DEF_ACCEL_CS_PIN, 1);

    // LED
    nrf_gpio_cfg_output(BSP_DEF_LED_RED_PIN);
    nrf_gpio_pin_write(BSP_DEF_LED_RED_PIN, 1);
        // LED
    nrf_gpio_cfg_output(BSP_DEF_LED_GREEN_PIN);
    nrf_gpio_pin_write(BSP_DEF_LED_GREEN_PIN, 1);
    
        // LED
    nrf_gpio_cfg_output(BSP_DEF_LED_BLUE_PIN);
    nrf_gpio_pin_write(BSP_DEF_LED_BLUE_PIN, 1);

    // VBAT_M_EN
    nrf_gpio_cfg_output(BSP_DEF_VBAT_M_EN_PIN);
    nrf_gpio_pin_write(BSP_DEF_VBAT_M_EN_PIN, 0);

    // BAT_CHARGED
    nrf_gpio_cfg_input(BSP_DEF_BAT_CHARGED_PIN, GPIO_PIN_CNF_PULL_Pullup);
    nrf_gpio_cfg_input(BSP_DEF_LSEN_INT_PIN, GPIO_PIN_CNF_PULL_Pullup);
    nrf_gpio_cfg_input(BSP_DEF_VAUX_MONITOR_PIN, GPIO_PIN_CNF_PULL_Pullup);
  
    uint32_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);

    app_timer_create(&m_reset_timer_id,
                                  APP_TIMER_MODE_SINGLE_SHOT,
                                  reset_timer_handler);
    app_timer_start(m_reset_timer_id, APP_TIMER_TICKS(30000), NULL);
}

/**
 * @brief Main loop.
 */

int main(void)

{
    setup();
    while (1)
    {
        // Wait for an event.
        __WFE();
        // Clear the internal event register.
        __SEV();
        __WFE();
    }
}

The GPIOs configuration is specific from my board. The problem happens when you power cycle the board and wait a few reset cycles. When it happen it will go away most of the times with another reset so will star just for a few seconds.

Any idea of the cause of the problem? I am convinced that it is related of the use of the external clock with bypass.

Best

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

hmolesworth — Fri, 19 Apr 2024 22:02:06 GMT

If using the softdevice have to go via the API to avoid a crash "If a SoftDevice is running, the clock is managed by the SoftDevice and all requests are handled by the SoftDevice. This function cannot be called from all interrupt priority levels in that case"

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Nguyen Hoan Hoang — Fri, 19 Apr 2024 21:52:11 GMT

Do you know that the HFCLK is used by UART, SPI, I2C ?

Turn your SPI, I2C off as I showed you to see what would happen.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Luis — Fri, 19 Apr 2024 20:44:58 GMT

I tested stoping the HFCLK right before going to sleep mode but it crashes the software. I guess it is something I cannot do when using the SoftDevice.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

hmolesworth — Fri, 19 Apr 2024 16:52:05 GMT

Maybe use HFCLKSTAT to see if it running periodically; if not needed issue HFCLKSTOP. Unfortunately there is no STOPPED event, but it is possible to see if it unexpectedly started:

Event:  CLOCK->EVENTS_HFCLKSTARTED      0x4000'0100 = 1 (No Enable Field)       IntEnable 0x4000'0300=         0
Event:  CLOCK->EVENTS_LFCLKSTARTED      0x4000'0104 = 1 (No Enable Field)       IntEnable 0x4000'0300=         0

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Luis — Fri, 19 Apr 2024 16:47:09 GMT

I did that. I checked all CNF, OUT, Pull Up/Down and the state of the pins with a scope. Everything as should be.

From my tests it looks like the HFCLK is on during the idle mode even when BLE is not enabled. I am trying to understand what is going on.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

hmolesworth — Fri, 19 Apr 2024 16:44:03 GMT

13K @ 3.3V is about 254uA; 13k-ish happens to be the port io pull-up resistance. Worth scanning all the port CNF registers on wakeup to see if there is one unexpectedly set.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Luis — Fri, 19 Apr 2024 16:28:34 GMT

Adding a bit more of information. I tested to add a standard timer to ran continuously and measured the current. The current goes up as expected as the timer is on during the sleep (idle) mode. However the extra 265uA never comes again, so it looks like that something is forcing the HFCLK to stay on during the sleep mode. Weirdly I do not directly use the HFCLK for nothing. Probably only the SoftDevice uses it for the BLE connection. Is there anyway to check what is making the HFCLK stay on. I tryed to look into all registers of the device but could not find anything.

Thank you!

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Nguyen Hoan Hoang — Fri, 19 Apr 2024 15:07:47 GMT

This is how power off.

// Undocumented Power down I2C. Nordic Bug with DMA causing high current consumption
#ifdef TWIM_PRESENT
*(volatile uint32_t *)((uint32_t)dev->pDmaReg + 0xFFC);
*(volatile uint32_t *)((uint32_t)dev->pDmaReg + 0xFFC) = 1;
*(volatile uint32_t *)((uint32_t)dev->pDmaReg + 0xFFC) = 0;
#else
*(volatile uint32_t *)((uint32_t)dev->pReg + 0xFFC);
*(volatile uint32_t *)((uint32_t)dev->pReg + 0xFFC) = 1;
*(volatile uint32_t *)((uint32_t)dev->pReg + 0xFFC) = 0;
#endif

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Luis — Fri, 19 Apr 2024 14:58:24 GMT

I was not powering off as it should not use a lot a power when not used. Anyway I did power off and on both and nothing. Also I checked all SPI and I2C level on the multimeter and they are as they are suposed to be.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Nguyen Hoan Hoang — Thu, 18 Apr 2024 21:00:50 GMT

Do you power off the I2C & SPI ? Disable only may still consume power. Gpio input with pull-up needs to disconnect as well.

One of the test I usually do is to create a firmware that does nothing. While a while(1) __WFE(); and gradually checking for leaks. Anything more than 1uA with that means hardware is leaking somewhere.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Luis — Thu, 18 Apr 2024 20:43:36 GMT

We do have a few and also use I2C and SPI. We checked the GPIO states and all of them are as they should be. The weird part is that the problem only exist during sleep mode, so the I2C or SPI pin would have to change state during the sleep. Also a 4.7K pullup would lead to more than 260uA of current.

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Nguyen Hoan Hoang — Thu, 18 Apr 2024 20:04:32 GMT

Any gpio as input that has pull-up ? or i2c ?

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Luis — Thu, 18 Apr 2024 19:58:44 GMT

Hello Nguyen,

Thank you for the reply. We are not using UART.

Any other ideas?

RE: Random ~265uA extra current consuption when NRF52832 is in sleep mode.

Nguyen Hoan Hoang — Thu, 18 Apr 2024 19:36:04 GMT

It's looks like the UART is still on. Are you using UART ?