Sanduhr

int shiftPin = 3; //SHCP
int storePin = 2; //STCP
int dataPin = 0; //DS
//globale Variable
//dient als Index für die aktive LED
//im Lauflicht
int activeIndex = -1;
void setup() {
  //setzen der Pins als Ausgang
  pinMode(storePin, OUTPUT);
  pinMode(shiftPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  //setzen des Pins am digitalen Pin D8
  //auf LOW quasi Status "AUS"
  digitalWrite(storePin, LOW);
}
void loop () {
  writeMuster();
  //eine kleine Pause von 150ms.
  delay(750);
}

void writeMuster() {
  if (activeIndex > 7) {
    activeIndex = 0;
  } else {
    activeIndex++;
  }

  int muster_oben[4] = {1, 1, 1, 1};
  int muster_unten[4] = {0, 0, 0, 0};
  if (activeIndex >= 1) {
    for (int i = 0; i < activeIndex; i++) {
      muster_oben[i] = 0;
      muster_unten[i] = 1;
    }
  }


  for (int i = 0; i < 4; i++) {
    digitalWrite(shiftPin, LOW);
    digitalWrite(dataPin, muster_oben[i]);
    digitalWrite(shiftPin, HIGH);
  }

  for (int i = 0; i < 4; i++) {
    digitalWrite(shiftPin, LOW);
    digitalWrite(dataPin, muster_unten[i]);
    digitalWrite(shiftPin, HIGH);
  }
  //schreiben der Daten
  digitalWrite(storePin, HIGH);
  delay(20); //eine kleine Pause
  //zurücksetzen
  digitalWrite(storePin, LOW);
}