// Pin definitions for 74HC595
const int dataPin = 11;   // DS
const int latchPin = 8;   // STCP
const int clockPin = 12;  // SHCP

// 7-segment digit codes (common cathode)
// Segments: A B C D E F G (DP optional)
// Bit order: Q0 = A, Q1 = B, ..., Q6 = G
const byte digitCodes[10] = {
  0b00111111, // 0
  0b00000110, // 1
  0b01011011, // 2
  0b01001111, // 3
  0b01100110, // 4
  0b01101101, // 5
  0b01111101, // 6
  0b00000111, // 7
  0b01111111, // 8
  0b01101111  // 9
};

void setup() {
  pinMode(dataPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
}

void loop() {
  for (int i = 0; i < 10; i++) {
    displayDigit(i);
    delay(1000); // Wait 1 second
  }
}

void displayDigit(int digit) {
  digitalWrite(latchPin, HIGH);
  shiftOut(dataPin, clockPin, MSBFIRST, digitCodes[digit]);
  digitalWrite(latchPin, LOW);
}