////////////////////////////////////////////////////////////////////////////////////////////////  
// Blinking an LED using ESP IDF with ESP32  
// 1) Understanding the gpio_reset_pin() function of the API  
// 2) Understanding the gpio_set_direction() function of the API  
// 3) Understanding the gpio_set_level() function of the API  
// 4) Understanding the gpio_get_level() function of the API  
////////////////////////////////////////////////////////////////////////////////////////////////  

#include <stdio.h>  
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"  
#include "driver/gpio.h" 

#define LED GPIO_NUM_2 // define the LED Pin  

void app_main(void)  
{  
    // Configure the peripheral according to the LED type */  
    gpio_reset_pin(LED); // First reset the gpio to default state  
    gpio_set_direction(LED, GPIO_MODE_OUTPUT); // Configure the GPIO direction as output_only  

    // Get into the loop  
    while (1) {  
        gpio_set_level(LED, true); // Set the GPIO output level to HIGH  
        if(gpio_get_level(LED)==1){
          printf("ON\n");
        }
        vTaskDelay(250 / portTICK_PERIOD_MS); // delay  
        gpio_set_level(LED, false); // Set the GPIO output level to LOW  
        if(gpio_get_level(LED)==0){
          printf("OFF\n");
        }
        vTaskDelay(250 / portTICK_PERIOD_MS); // delay  
    }  
}