#include <ESP32Servo.h>

#define TRIG_PIN  26 // ESP32 pin GIOP26 connected to Ultrasonic Sensor's TRIG pin
#define ECHO_PIN  25 // ESP32 pin GIOP25 connected to Ultrasonic Sensor's ECHO pin
#define SERVO_PIN 27  // ESP32 pin GIOP26 connected to Servo Motor's pin
#define LED_PIN   18 // ESP32 pin GIOP17 connected to LED's pin
#define LED_PIN2  19
#define LED_PIN3  5
#define DISTANCE_THRESHOLD 100 // centimeters
#define DISTANCE_THRESHOLD2 200
#define DISTANCE_THRESHOLD3 300

Servo servo; // create servo object to control a servo

// variables will change:
float duration_us, distance_cm;

void setup() {
  Serial.begin (9600);       // initialize serial port
  pinMode(TRIG_PIN, OUTPUT); // set ESP32 pin to output mode
  pinMode(ECHO_PIN, INPUT);  // set ESP32 pin to input mode
  servo.attach(SERVO_PIN);   // attaches the servo on pin 9 to the servo object
  pinMode(LED_PIN, OUTPUT);  // set ESP32 pin to output mode
  pinMode(LED_PIN2, OUTPUT);
  pinMode(LED_PIN3, OUTPUT);
  servo.write(90);
}

void loop() {
  // generate 10-microsecond pulse to TRIG pin
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // measure duration of pulse from ECHO pin
  duration_us = pulseIn(ECHO_PIN, HIGH);
  // calculate the distance
  distance_cm = 0.017 * duration_us;


  //LED 1
  if (distance_cm < DISTANCE_THRESHOLD)
  {
     digitalWrite(LED_PIN, HIGH); // turn on LED
     servo.write(60); //servo rotate 60 degree
  }

  else
  {
     digitalWrite(LED_PIN, LOW);
     servo.write(0);
  }

        //LED 2
        if (distance_cm > DISTANCE_THRESHOLD && distance_cm < DISTANCE_THRESHOLD2)
        {
           digitalWrite(LED_PIN2, HIGH); // turn on LED
           servo.write(120); // servo rotate 120 degree
        }

        else if (distance_cm < DISTANCE_THRESHOLD2)
        {
           digitalWrite(LED_PIN2, LOW);
        }

        else
        {
           digitalWrite(LED_PIN2, LOW);
        }

               //LED 3
               if (distance_cm > DISTANCE_THRESHOLD2 && distance_cm < DISTANCE_THRESHOLD3)
               {
                   digitalWrite(LED_PIN3, HIGH); // turn on LED
                   servo.write(180); // servo rotate 180 degree
               }
               else if (distance_cm < DISTANCE_THRESHOLD3)
               {
                   digitalWrite(LED_PIN3, LOW);
               }
               else
               {
                   digitalWrite(LED_PIN3, LOW);
               }


  // print the value to Serial Monitor
  Serial.print("distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");

  delay(500);
}