nRF52840 is anything dependent on power management?

RE: nRF52840 is anything dependent on power management?

Øyvind — Wed, 13 Nov 2019 13:51:24 GMT

[quote user="BEplane"]My expectation is that all other features will work, and the processor will not go to sleep. Causing a small increase in power consumption.[/quote]

Yes, that is correct. Removing the nrf_pwr_mgmt_run(), not the idle_state_handle(), will only prevent device from sleeping (power saving).

RE: nRF52840 is anything dependent on power management?

BEplane — Tue, 12 Nov 2019 14:35:35 GMT

Sorry I copied from the main browser URL, not the Copy URL button, so it went to the previous page I was viewing. I was referring to the power management

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/lib_pwr_mgmt.html

Yes that is is function that is being called. I am inquiring if leaving the power management setup, but removing that call (nrf_pwr_mgmt_run) will have any negative effect of properly running other features provided by Nordic.

This is a broad question, but the power management is baked into most examples, so I would like to better understand any unseen complications for removing only the call (nrf_pwr_mgmt_run) from a project.

My expectation is that all other features will work, and the processor will not go to sleep. Causing a small increase in power consumption.

RE: nRF52840 is anything dependent on power management?

Øyvind — Tue, 12 Nov 2019 13:27:06 GMT

Hi BEplane,

[quote user=""]From the link above, the DFU is the only feature that needs the power management[/quote]

Not sure what you are referring to. The link points to the clock chapter of nRF52832, with no mention of DFU.

[quote user=""]We are trying to remove nrf_pwr_mgmt_run() from main, and determine if any unknown issues will arise[/quote]

What example are you running? All examples call nrf_pwr_mgmt_run() in idle_state_handle():

/**@brief Function for handling the idle state (main loop).
 *
 * @details Handles any pending log or key operations, or both, then sleeps until the next event occurs.
 */
static void idle_state_handle(void)
{
    ret_code_t err_code;
    
    err_code = nrf_ble_lesc_request_handler();
    APP_ERROR_CHECK(err_code);
    
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}

void nrf_pwr_mgmt_run(void)
{
    PWR_MGMT_FPU_SLEEP_PREPARE();
    PWR_MGMT_SLEEP_LOCK_ACQUIRE();
    PWR_MGMT_CPU_USAGE_MONITOR_SECTION_ENTER();
    PWR_MGMT_DEBUG_PIN_SET();

    // Wait for an event.
#ifdef SOFTDEVICE_PRESENT
    if (nrf_sdh_is_enabled())
    {
        ret_code_t ret_code = sd_app_evt_wait();
        ASSERT((ret_code == NRF_SUCCESS) || (ret_code == NRF_ERROR_SOFTDEVICE_NOT_ENABLED));
        UNUSED_VARIABLE(ret_code);
    }
    else
#endif // SOFTDEVICE_PRESENT
    {
        // Wait for an event.
        __WFE();
        // Clear the internal event register.
        __SEV();
        __WFE();
    }

    PWR_MGMT_DEBUG_PIN_CLEAR();
    PWR_MGMT_CPU_USAGE_MONITOR_SECTION_EXIT();
    PWR_MGMT_SLEEP_LOCK_RELEASE();
}

The DFU service (components\ble\ble_services\ble_dfu\ble_dfu.h), however, calls

nrf_pwr_mgmt_shutdown(NRF_PWR_MGMT_SHUTDOWN_GOTO_DFU);

/**@brief Function for shutting down the system.
 *
 * @param[in] shutdown_type     Type of operation.
 *
 * @details All callbacks will be executed prior to shutdown.
 */
void nrf_pwr_mgmt_shutdown(nrf_pwr_mgmt_shutdown_t shutdown_type);

I suggest having a look at the Power Management library (components\libraries\pwr_mgmt\nrf_pwr_mgmt.h)