const int trigger = 2;
const int echo = 3;
const int red = 8;
const int blue = 9;
const int green = 10;

void setup(){
  Serial.begin(9600);
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(red, OUTPUT);
  pinMode(blue, OUTPUT);
  pinMode(green, OUTPUT);
}
void loop(){
  digitalWrite(trigger, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigger, LOW);

  long duration = pulseIn(echo, HIGH);
  float distance = duration * 0.017;
  Serial.println(distance);


  if(distance <= 100.0){
    digitalWrite(green, HIGH);
  }
  else{
    digitalWrite(green, LOW);
  }
  if(distance <= 80.0){
    digitalWrite(blue, HIGH);
  }
  else{
    digitalWrite(blue, LOW);
  }
  if(distance <= 50.0){
    digitalWrite(red, HIGH);
  }
  else{
    digitalWrite(red, LOW);
  }
}