// Pin definitions for 74HC595
const int latchPin = 5; // Latch pin (RCLK)
const int clockPin = 6; // Clock pin (SCLK)
const int dataPin = 4;  // Data pin (DS)

// Segment patterns for digits 0-9 for common cathode
const byte digitSegments[10] = {
  B11111100, // 0
  B01100000, // 1
  B11011010, // 2
  B11110010, // 3
  B01100110, // 4
  B10110110, // 5
  B10111110, // 6
  B11100000, // 7
  B11111110, // 8
  B11110110  // 9
};

// Digit control patterns
const byte digitControl[4] = {
  B11111110, // Digit 1 (Q0)
  B11111101, // Digit 2 (Q1)
  B11111011, // Digit 3 (Q2)
  B11110111  // Digit 4 (Q4)
};

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

void loop() {
  for (int i = 0; i <= 9999; i++) {
    displayNumber(i);
    delay(40); // Adjust delay as needed
  }
}

void displayNumber(int number) {
  byte digits[4] = {0};

  // Split number into individual digits
  for (int i = 0; i < 4; i++) {
    digits[i] = number % 10;
    number /= 10;
  }

  // Display each digit
  for (int digit = 0; digit < 4; digit++) {
    digitalWrite(latchPin, LOW);

    // Send the segment data for the current digit
    shiftOut(dataPin, clockPin, LSBFIRST, digitSegments[digits[digit]]);
    // Send the digit control data
    shiftOut(dataPin, clockPin, MSBFIRST, digitControl[digit]);

    digitalWrite(latchPin, HIGH);

    // Small delay to avoid flickering
    delay(5);
  }
}