How to use Timer to count pulse width

[Giang]

Hi all , 

I have to decode the IR pulse for remote . I want to use Timer to count pulse width .I know how to use timer to create a time , but I don't know how to use timer to count. Please show me a solution . Thank 

[norin saiyed]

Hi,

You can use app_timer_cnt_get(); for getting count value .

[Giang]

#include <stdbool.h>
#include <stdint.h>
#include "nrf.h"
#include "nrf_drv_timer.h"
#include "bsp.h"
#include "app_error.h"

uint32_t counter;


const nrf_drv_timer_t TIMER_LED = NRF_DRV_TIMER_INSTANCE(0);

/**
 * @brief Handler for timer events.
 */
void timer_led_event_handler(nrf_timer_event_t event_type, void* p_context)
{
    static uint32_t i;
    uint32_t led_to_invert = ((i++) % LEDS_NUMBER);

    switch (event_type)
    {
        case NRF_TIMER_EVENT_COMPARE0:
				nrf_gpio_pin_toggle(LED_1);
				NRF_TIMER2->TASKS_CAPTURE[0] = 1;
				counter = NRF_TIMER2->CC[0];
            break;

        default:
            //Do nothing.
            break;
    }
}


/**
 * @brief Function for main application entry.
 */
int main(void)
{
    uint32_t time_ms = 1000; //Time(in miliseconds) between consecutive compare events.
    uint32_t time_ticks;
    uint32_t err_code = NRF_SUCCESS;

    //Configure all leds on board.
    bsp_board_leds_init();

    //Configure TIMER_LED for generating simple light effect - leds on board will invert his state one after the other.
    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
		timer_cfg.frequency = NRF_TIMER_FREQ_1MHz;
    err_code = nrf_drv_timer_init(&TIMER_LED, &timer_cfg, timer_led_event_handler);
    APP_ERROR_CHECK(err_code);		
//32 bit , 1M	
    nrf_drv_timer_extended_compare(
         &TIMER_LED, NRF_TIMER_CC_CHANNEL0, 1000000, NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);

    nrf_drv_timer_enable(&TIMER_LED);




    while (1)
    {

    }
}

/** @} */

It my code , but I don't get counter , it alway = 0. Can you explain for me?

[norin saiyed]

you can use application timer. here is the tutorial link. Hope this helps.

https://devzone.nordicsemi.com/tutorials/b/software-development-kit/posts/application-timer-tutorial

then use app_timer_cnt_get function