const int LED_GREEN = 11;
const int LED_YELLOW = 12;
const int LED_RED = 13;
const int POTMETER = A0;
float Spenning;
int innverdi;
int currentLight = 0;

void setup() {
  Serial.begin(9600);
  pinMode(A0, INPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_YELLOW, OUTPUT);
  pinMode(LED_RED, OUTPUT);
}

void loop() {
  innverdi = analogRead(A0);
  Spenning=((5.0/1023.0) * innverdi);  
  Serial.println(Spenning);
  int lightToLightUp = check(Spenning);
  if(lightToLightUp != currentLight){
    turnOnLight(lightToLightUp);
  }
}

int check(float Spenning){
    if (Spenning < 1.63){
    // Rødt lys
    return 0;
  }
  if(Spenning <= 3.3){
    // Gult lys
    return 1;
  }
  // Grønt lys
  return 2;
}

void turnOnLight(int Lys){
  digitalWrite(LED_RED, LOW);
  digitalWrite(LED_YELLOW, LOW);
  digitalWrite(LED_GREEN, LOW);

  if (Lys == 0){
    // Tenn dæ røe lyse
    digitalWrite(LED_RED, HIGH);
    currentLight = 0;
  }
  if(Lys == 1){
    // Tenn dæ gule lyse
    digitalWrite(LED_YELLOW, HIGH);
    currentLight = 1;
  }
   if(Lys == 2){
    // Tenn dæ grønne lyse
    digitalWrite(LED_GREEN, HIGH);
    currentLight = 2;
  }
}