#define CLK 2
#define DT 3

const int ledPins[8] = {5, 6, 7, 8, 9, 10, 11, 12};  
int ledIndex = 0;
int lastStateCLK;

void setup() {
  pinMode(CLK, INPUT);
  pinMode(DT, INPUT);

  for (int i = 0; i < 8; i++) {
    pinMode(ledPins[i], OUTPUT);
  }

  lastStateCLK = digitalRead(CLK);
  updateLEDs();
}

void loop() {
  int currentStateCLK = digitalRead(CLK);

  if (currentStateCLK != lastStateCLK) {
    if (digitalRead(DT) != currentStateCLK) {
      ledIndex++;
    } else {
      ledIndex--;
    }

    if (ledIndex > 7) ledIndex = 0;
    if (ledIndex < 0) ledIndex = 7;

    updateLEDs();
  }

  lastStateCLK = currentStateCLK;
}


void updateLEDs() {
  for (int i = 0; i < 8; i++) {
    digitalWrite(ledPins[i], (i == ledIndex) ? HIGH : LOW);
  }
}