#define LED_ROT 13
#define LED_GELB 12
#define LED_GRUEN 10

void setup()
{
  pinMode(LED_ROT, OUTPUT);
  pinMode(LED_GELB, OUTPUT);
  pinMode(LED_GRUEN, OUTPUT);
}

void loop() 
{
  digitalWrite(LED_ROT,   HIGH);
  digitalWrite(LED_GELB,  LOW);
  digitalWrite(LED_GRUEN, LOW);
  delay(2000);
  digitalWrite(LED_ROT,   HIGH);
  digitalWrite(LED_GELB,  HIGH);
  digitalWrite(LED_GRUEN, LOW);
  delay(1000);
  digitalWrite(LED_ROT,   LOW);
  digitalWrite(LED_GELB,  LOW);
  digitalWrite(LED_GRUEN, HIGH);
  delay(3000);
  digitalWrite(LED_ROT,   LOW);
  digitalWrite(LED_GELB,  HIGH);
  digitalWrite(LED_GRUEN, LOW);
  delay(1000);
}