#define LED_ROT 13
#define LED_GELB 12
#define LED_GRUEN 11
#define TASTE 7

void setup()
{
  pinMode(LED_ROT, OUTPUT);
  pinMode(LED_GELB, OUTPUT);
  pinMode(LED_GRUEN, OUTPUT);
  pinMode(TASTE, INPUT);
  digitalWrite(TASTE, HIGH);
}

void loop() 
{
  digitalWrite(LED_ROT,   LOW);
  digitalWrite(LED_GELB,  LOW);
  digitalWrite(LED_GRUEN, HIGH);
  while(digitalRead(TASTE) == HIGH)
  {}
  delay(2000);
  digitalWrite(LED_GRUEN, LOW);
  digitalWrite(LED_GELB,  HIGH);
  delay(2000);
  digitalWrite(LED_ROT,   HIGH);
  digitalWrite(LED_GELB,  LOW);
  delay(4000);
  digitalWrite(LED_GELB,  HIGH);
  delay(2000);
}