Time taken by a code snippet

[Sai Kiran]

Hi

I want to know the time taken(in us) by a code snippet. I had a look at app_timer functionality with the help of this post. But the timer value always shows 0. I am not sure on how to create a dummy timer. Can someone help me with this? Also which is more accurate, RTC or APP_TIMER?

Thanks in advance.

-Sai Kiran

[Edvin]

Sorry. I wrote that code without testing it. I was missed the part that the tasks has to be set to 1 (like the NRF_TIMER3->TASKS_START = 1;)

Try the following:

void timer_init(void)
{
    NRF_TIMER3->BITMODE         = TIMER_BITMODE_BITMODE_32Bit << TIMER_BITMODE_BITMODE_Pos;
    NRF_TIMER3->PRESCALER       = 4;
    NRF_TIMER3->SHORTS          = TIMER_SHORTS_COMPARE0_CLEAR_Disabled << TIMER3_CC_NUM;
    NRF_TIMER3->MODE            = TIMER_MODE_MODE_Timer << TIMER_MODE_MODE_Pos;
    
    NRF_TIMER3->TASKS_START = 1;
}

int main(void)
{
    bsp_board_init(BSP_INIT_LEDS);

    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    NRF_LOG_DEFAULT_BACKENDS_INIT();
    
    timer_init();
    
    NRF_LOG_INFO("test");
    while (1)
    {
        bsp_board_led_invert(0);
        NRF_TIMER3->TASKS_CAPTURE[0] = 1;
        nrf_delay_ms(1000);
        NRF_TIMER3->TASKS_CAPTURE[1] = 1;
        NRF_LOG_INFO("diff_time: %08d µs", (NRF_TIMER3->CC[1] - NRF_TIMER3->CC[0]));
        
        NRF_LOG_FLUSH();
        __WFE();
    }
}

BR,

Edvin