// Globale Variablen
int  iWert;

void setup() {

  pinMode(8,  OUTPUT);
  pinMode(9,  OUTPUT);
  pinMode(10, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  
  iWert = analogRead(A5);       // Analogwert einlesen
  Serial.println(iWert*0.005);  // 1024 * 5mV = 5.12V

  if (iWert > 480)              // 480 * 5mV = 2.4V (bis 5.12V)
  {
    digitalWrite(8, HIGH);      // Grün
    digitalWrite(9, LOW);    
    digitalWrite(10,LOW);    
  }
  else if (iWert > 160)         // 160 * 5mV = 0.8V (bis 2.4V)
  {
    digitalWrite(8, LOW);       // Gelb
    digitalWrite(9, HIGH);    
    digitalWrite(10,LOW);    
  }
  else                          //   0 * 5mV = 0.0V (bis 0.8V)
  {
    digitalWrite(8, LOW);       // Rot
    digitalWrite(9, LOW);    
    digitalWrite(10,HIGH);    
  }
  delay(100);
}