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  • Case ID: 338336
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Spikes in current consumption after using semaphores

sumit-adep





can anyone tell me what are these spikes

i am some part of my code:

_SPRINTLN(DEBUG_INFO, "LOW-PWR-SYS-ON"); // debug log to show device will enter standby state

        // turn off peripherals
        pm_device_action_run(uart_dev, PM_DEVICE_ACTION_SUSPEND);
        pm_device_action_run(adc_dev, PM_DEVICE_ACTION_SUSPEND);

        // Block (sleep) the main thread, it will wake up on GPIO interrupt or timer timeout
        k_sem_take(&main_sem, K_FOREVER);

        pm_device_action_run(uart_dev, PM_DEVICE_ACTION_RESUME);
        pm_device_action_run(adc_dev, PM_DEVICE_ACTION_RESUME);

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  • 0 in reply to Edvin

    I have applied below changes in mode=1 and did not see any raise in current once it enters into SYSTEM_OFF mode.

    void shutdown_cpu(bool mode)
{
    led_ctrl(HIGH, HIGH, HIGH);
    du_radio_sleep(DU_SLEEP_SHUTDOWN);
    sx126x_hal_deinit();

    // clear all the wakeup reasons before going to sleep
    clear_wakeup_reason();

    // get zephyr-console pointer:
    const struct device *uart_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_console));

    if (mode)
    {
        _SPRINTLN(DEBUG_INFO, "LOW-PWR-SYS-OFF"); // debug log to show device will enter shutdown state
        gf_pwr_once = 0;

        // Disable the UART, SPI, I2C, and other communication peripherals
        NRF_UART0->ENABLE = UART_ENABLE_ENABLE_Disabled;
        NRF_SPI0->ENABLE = SPI_ENABLE_ENABLE_Disabled;
        NRF_TWI0->ENABLE = TWI_ENABLE_ENABLE_Disabled;

        // Disable the ADC (if enabled)
        NRF_SAADC->ENABLE = SAADC_ENABLE_ENABLE_Disabled;

        // Disable RTC
        NRF_RTC0->TASKS_STOP = 1;

        // Disable timers
        NRF_TIMER0->TASKS_STOP = 1;

        // Disable PWM
        NRF_PWM0->ENABLE = PWM_ENABLE_ENABLE_Disabled;

        // Disable the radio (Bluetooth)
        NRF_RADIO->POWER = RADIO_POWER_POWER_Disabled;

        // Disable the CPU clock and enter low power mode
        NRF_POWER->TASKS_LOWPWR = 1;

        // Enter System OFF mode
        NRF_POWER->SYSTEMOFF = 1; // This will cause the chip to enter System OFF mode
    }
    else
    {
        _SPRINTLN(DEBUG_INFO, "LOW-PWR-SYS-ON"); // debug log to show device will enter standby state

        // turn off peripherals
        pm_device_action_run(uart_dev, PM_DEVICE_ACTION_SUSPEND);
        // Disable the UART, SPI, I2C, and other communication peripherals

        NRF_SPI0->ENABLE = SPI_ENABLE_ENABLE_Disabled;
        NRF_TWI0->ENABLE = TWI_ENABLE_ENABLE_Disabled;

        // Disable the ADC (if enabled)
        NRF_SAADC->ENABLE = SAADC_ENABLE_ENABLE_Disabled;

        // Disable RTC
        NRF_RTC0->TASKS_STOP = 1;

        // Disable timers
        NRF_TIMER0->TASKS_STOP = 1;

        // Disable PWM
        NRF_PWM0->ENABLE = PWM_ENABLE_ENABLE_Disabled;

        // Disable the radio (Bluetooth)
        NRF_RADIO->POWER = RADIO_POWER_POWER_Disabled;

        // Disable the CPU clock and enter low power mode
        NRF_POWER->TASKS_LOWPWR = 1;

        // If 'use_timer' is true, it means we want to use the timer to wake up the device after 'RTC_TIME' seconds.
        // This will block the main thread until the timer expires or an interrupt occurs (based on the RTC_TIME).
        if (use_timer)
        {

            // Wait for the semaphore to be given, with a timeout of 'RTC_TIME' seconds.
            // If the semaphore is not given within this period, it means a timeout has occurred.
            int ret = k_sem_take(&main_sem, K_SECONDS(RTC_TIME)); // Store the return value for error handling

            // Error handling based on the return value of k_sem_take:
            if (ret == 0)
            {
                // Semaphore successfully taken, no timeout occurred
                timeout_flag = false; // Reset the timeout flag
            }
            else if (ret == -EBUSY)
            {
                // The semaphore was already taken (not a typical case for k_sem_take with timeout)
                _SPRINTLN(DEBUG_ERROR, "Semaphore already taken. This should not happen.");

                k_msleep(5000);
                k_sem_take(&main_sem, K_SECONDS(RTC_TIME));
            }
            else if (ret == -EAGAIN)
            {
                // Timeout occurred
                timeout_flag = true; // Set the timeout flag to indicate the timer has expired
                _SPRINTLN(DEBUG_WARNING, "Timer expired without semaphore being taken.");
            }
            else
            {
                // Catch any other unexpected error codes
                _SPRINTLN(DEBUG_ERROR, "Unexpected error during semaphore take operation: %d", ret);
                k_msleep(5000);
                k_sem_take(&main_sem, K_SECONDS(RTC_TIME));
            }
        }
        else
        {
            // If 'use_timer' is false, block the main thread indefinitely until a GPIO interrupt occurs.
            // The main thread will wake up when a semaphore is given by an ISR.
            int ret = k_sem_take(&main_sem, K_FOREVER); // Store the return value for error handling

            // Error handling based on the return value of k_sem_take:
            if (ret != 0)
            {
                // If we exit unexpectedly (e.g., an ISR failure or other issue), log the error
                _SPRINTLN(DEBUG_ERROR, "Failed to take semaphore with indefinite wait.");
                k_msleep(5000);
                k_sem_take(&main_sem, K_FOREVER);
            }
        }

        pm_device_action_run(uart_dev, PM_DEVICE_ACTION_RESUME);
    }

    adc_init();

    // lines to be executed after wakeup:
    du_radio_init();
    du_radio_sleep(DU_SLEEP_STANDBY);
    _SPRINTLN(DEBUG_CRITICAL, "WAKE-UP");
    k_msleep(100); // Simultaneous Button press
}

  • 0 in reply to Edvin

    CONFIG_PM=y
    This line does not seem to be doing anything.

  • 0 in reply to sumit-adep

    Again original issue which was associated with spikes in current consumption while main thread is sleeping or blocked with use of semaphore is unresolved
    +
    Plus current consumption of overall pcb is ~10 uA, where nrf52811 SoC is consuming around ~7 uA.

    For this refer mode=0.

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