#include <ESP32Servo.h>

const int trigPin = 22; 
const int echoPin = 21;
const int servoPin = 25; 
const int buzzerPin = 19; 
const int led1Pin = 26; 
const int led2Pin = 27; 
const int led3Pin = 14; 

Servo myServo;

void setup() {
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(servoPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  pinMode(led3Pin, OUTPUT);
  
  myServo.attach(servoPin);
}

void loop() {
  long duration, distance;
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration * 0.034) / 2;

  if (distance <= 300) {
    digitalWrite(led1Pin, HIGH);
  } else {
    digitalWrite(led1Pin, LOW);
  }
  
  if (distance <= 250) {
    digitalWrite(led2Pin, HIGH);
  } else {
    digitalWrite(led2Pin, LOW);
  }

  if (distance <= 200) {
    digitalWrite(led3Pin, HIGH);
    myServo.write(180); //kita kena set berapa darjah servo kena pusing.
    tone(buzzerPin, 1000); 
    delay(1000); 
    noTone(buzzerPin); 
  } else {
    digitalWrite(led3Pin, LOW);
    myServo.write(0);
    noTone(buzzerPin);
  }
  
  delay(100);
}