Proper way to configure clock with HFXO in a FreeRTOS project

[jPolo777]

Hi, I'm working on a FreeRTOS (I just start to use it, so I'm a beginner) project in wish we want to use an external 32 MHz crystal. The program has a task that should be executed during a period of time of 125ms. Using the internal clock, the task executes in the expected time. However, when I implemented the HFXO, the execution time is almost 3.5*expected time (~430ms). Here's part of the code how I initialize the clock based on Clock driver - legacy layer:

extern TaskHandle_t TSK_test_handle;

/*Event handler of the code*/
static void clock_hfck_rdy( nrf_drv_clock_evt_type_t event )
{
	switch(event)
	{
		case NRF_DRV_CLOCK_EVT_HFCLK_STARTED:
			break;
		case NRF_DRV_CLOCK_EVT_LFCLK_STARTED:
			break;
		case NRF_DRV_CLOCK_EVT_CAL_DONE:
			break;
		case NRF_DRV_CLOCK_EVT_CAL_ABORTED:
			break;
		default:
			break;
	}
}

static void init_clock( void )
{
	APP_ERROR_CHECK( nrf_drv_clock_init());
	
	static nrf_drv_clock_handler_item_t clock_handler =
	{
			.event_handler = clock_hfck_rdy
	};
	nrf_drv_clock_hfclk_request(&clock_hfck_rdy);
}

int main(void)
{
    nrf_delay_ms(100);
    init_clock();
    
    UNUSED_VARIABLE(xTaskCreate(
								TSK_test,
								"TSK_test",
								configMINIMAL_STACK_SIZE+100,
								NULL,
								2,
								&TSK_test_handle));
								
	/*Other tasks....*/
	
	vTaskStartScheduler();
	
    while (true)
	{
	}
}

/////////////////////////////////////////////////////

/*EXTERNAL MODULE - Task definition*/

#define SAMPLE_TIME_TICK 125
TaskHandle_t TSK_test_handle;

void TSK_test(void)
{
    vTaskDelay(250);
    TickType_t xLastWakeTime = xTaskGetTickCount();
    while(True)
    {
        /*Some code...*/
        vTaskDelayUntil( &xLastWakeTime, SAMPLE_TIME_TICK );
    }
}

Any help to figure out what I'm doing wrong to make the program run slower with the external crystal will be very appreciated.

Thanks!

[run_ar]

Hi,

Which SDK are you using? and did you see the example we have for freertos: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/freertos.html

Also check out the documentation her: nrf_drv_clock_lfclk_request

And maybe also use nrf_drv_clock_hfclk_request  to check if the clock is started before proceeding from clock init.