const int dataPin = 25;
const int clockPin = 27;
const int latchPin = 26;

// Segment states for digits 0-9
byte segmentStates[] = {
  0b11000000, // 0: A, B, C, D, E, F
  0b11111001, // 1: B, C
  0b10100100, // 2: A, B, D, E, G
  0b10110000, // 3: A, B, C, D, G
  0b10011001, // 4: B, C, F, G
  0b10010010, // 5: A, C, D, F, G
  0b10000010, // 6: A, C, D, E, F, G
  0b11111000, // 7: A, B, C
  0b10000000, // 8: A, B, C, D, E, F, G
  0b10010000  // 9: A, B, C, D, F, G
};

// Control states for the digits (anode or cathode selection)
byte digitStates[] = {
  0b00000001, // First digit
  0b00000010, // Second digit
  0b00000100  // Third digit
};

void setup() {
  Serial.begin(115200);
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
}

void loop() {
  // Test the display with a number
  displayNumber(1.5); // Example: Display "123"
  delay(1000);

  displayNumber(456); // Example: Display "456"
  delay(1000);

  displayNumber(789); // Example: Display "789"
  delay(1000);
}

// Function to convert an integer to 7-segment display
void displayNumber(int number) {
  number = constrain(number, 0, 999); // Ensure the number is within range (0-999)
  
  // Split the number into individual digits
  int hundreds = number / 100;          // Hundreds place
  int tens = (number / 10) % 10;        // Tens place
  int units = number % 10;              // Units place

  // Display each digit for a short period (multiplexing)
  for (int i = 0; i < 50; i++) {        // Repeat to create a stable display
    // Display hundreds place (digit 0)
    shiftData(segmentStates[hundreds], digitStates[0]);
    delay(5);

    // Display tens place (digit 1)
    shiftData(segmentStates[tens], digitStates[1]);
    delay(5);

    // Display units place (digit 2)
    shiftData(segmentStates[units], digitStates[2]);
    delay(5);
  }
}

// Function to send data to the shift register
void shiftData(byte segmentState, byte digitState) {
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, segmentState);
  shiftOut(dataPin, clockPin, MSBFIRST, digitState);
  digitalWrite(latchPin, HIGH);
}