main.c

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

#define TIMER1_INSTANCE_INDEX      (TIMER0_ENABLED)


APP_PWM_INSTANCE(PWM1,1);                   // Create the instance "PWM1" using TIMER1.

static volatile bool ready_flag;            // A flag indicating PWM status.

void pwm_ready_callback(uint32_t pwm_id)    // PWM callback function
{
    ready_flag = true;
}

int main(void)
{
    ret_code_t err_code;
    
    app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(2000L, BSP_LED_0);

    pwm1_cfg.pin_polarity[1] = APP_PWM_POLARITY_ACTIVE_HIGH;

    APP_ERROR_CHECK(err_code);
    app_pwm_enable(&PWM1);


    /* Initialize and enable PWM. */
    err_code = app_pwm_init(&PWM1,&pwm1_cfg,pwm_ready_callback);

    
    while(true)
    {
        int dutyCycle = 0;
        ready_flag = false;
        while(!ready_flag) {
            APP_ERROR_CHECK(app_pwm_channel_duty_set(&PWM1, 0, dutyCycle));
            nrf_delay_ms(25);
        }
    }
    
}