#include <Servo.h>

Servo myServo;

long distance;
int duration;

const int redLedPin = 3;
const int greenLedPin = 4;
const int buzzerPin = 5;
const int trigPin = 6;
const int echoPin = 7;
const int servoPin = 8;

const int distanceMin = 50;


void setup() {
  // put your setup code here, to run once:
  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  myServo.attach(servoPin);
  myServo.write(0);

  Serial.begin(9600);

}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin,HIGH);
  distance = duration * 0.034 /2;

  Serial.print("Distance: ");
  Serial.println(distance);
  Serial.println("cm");
  delay(500);

  if(distance <= distanceMin && distance > 0) {
    digitalWrite(redLedPin, LOW);
    digitalWrite(greenLedPin, HIGH);
    digitalWrite(buzzerPin, HIGH);
    myServo.write(90);
    delay(3000);
  }
  else {
    digitalWrite(redLedPin, HIGH);
    digitalWrite(greenLedPin, LOW);
    digitalWrite(buzzerPin, LOW);
    myServo.write(0);
    
  }
  delay(100);

}