#define LED_ROT  11
#define LED_GELB 10
#define LED_GRUEN 9

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_ROT, OUTPUT);
  pinMode(LED_GELB, OUTPUT);
  pinMode(LED_GRUEN, OUTPUT);
}

void rot() {
  digitalWrite(LED_ROT, HIGH);  
  digitalWrite(LED_GELB, LOW);  
  digitalWrite(LED_GRUEN, LOW);
}

void rotgelb() {
  digitalWrite(LED_ROT, HIGH);  
  digitalWrite(LED_GELB, HIGH);   
  digitalWrite(LED_GRUEN, LOW);
}

// the loop function runs over and over again forever
void loop() {
  // Phase 1: rot
  rot();
  delay(3000);

  // Phase 2: rot-gelb
  rotgelb();
  delay(1000);

  // Phase 3: gruen
  digitalWrite(LED_ROT, LOW);  
  digitalWrite(LED_GELB, LOW);  
  digitalWrite(LED_GRUEN, HIGH);
  delay(3000);

  // Phase 4: gelb
  digitalWrite(LED_ROT, LOW);  
  digitalWrite(LED_GELB, HIGH);   
  digitalWrite(LED_GRUEN, LOW);
  delay(1000);
}