#define rot 7
#define gelb 6
#define gruen 5
#define PIN_TRIG 8
#define PIN_ECHO 9

int sensor = 0;
void setup() {

  pinMode(rot, OUTPUT);
  pinMode(gelb, OUTPUT);
  pinMode(gruen, OUTPUT);
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);


}


void loop(){
  
  digitalWrite(PIN_TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  // Read the duration of the pulse received by the echo pin
  int duration = pulseIn(PIN_ECHO, HIGH);

  int distance = duration *0.0365 /2;
  //int distance = (duration * 0.034 / 2) * 10;


  digitalWrite (PIN_TRIG, HIGH);
  delay(500);
  digitalWrite (PIN_TRIG, LOW);
  int rotedis = 20;
  int gelbedis = 50;
  int gruenedis = 100;
//  int distance = digitalRead(9);


  if (distance >= gruenedis) {
    digitalWrite(gruen, HIGH);
    digitalWrite(gelb, LOW);
    digitalWrite(rot, LOW);
    
  }

  if (distance < gruenedis && distance > rotedis) {
    digitalWrite(gelb, HIGH);
    digitalWrite(gruen, LOW);
    digitalWrite(rot, LOW);
  }

  if (distance <= rotedis) {
    digitalWrite (rot, HIGH);
    digitalWrite(gelb, LOW);
    digitalWrite(gruen, LOW);
    
  }

Serial.print(distance);


}