#include <Servo.h>

#define trigPin 13
#define echoPin 12
#define ledG 7
#define ledO 6
#define ledR 5

Servo barrier;

void setup() {
  // put your setup code here, to run once:
  Serial.begin (9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  pinMode(ledG, OUTPUT);
  pinMode(ledO, OUTPUT);
  pinMode(ledR, OUTPUT);

  barrier.attach(9);
}

void loop() {
  // put your main code here, to run repeatedly:
   
  long duration, distance;
  digitalWrite(trigPin, LOW);  
  delayMicroseconds(2); 
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10); 
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = 0.03435 * (duration / 2);

  Serial.println(String(distance+1) + "cm");


  if (distance >= 100) {  
    digitalWrite(ledG, HIGH);
    digitalWrite(ledO, LOW);
    digitalWrite(ledR, LOW);
    barrier.write(90);
  } 
  
  else if (distance >= 51) {
    digitalWrite(ledG, LOW);
    digitalWrite(ledO, HIGH);
    digitalWrite(ledR, LOW);
    barrier.write(90);
  } 
  
  else if (distance <=50) {
    digitalWrite(ledG, LOW);
    digitalWrite(ledO, LOW);
    digitalWrite(ledR, HIGH);
    barrier.write(0);
  } 
}