const int segmentPins[8] = {2, 3, 4, 5, 6, 7, 8, 9};


const int digitPins[4] = {10, 11, 12, 13};


const byte digitPatterns[10][8] = {
  {1, 1, 1, 1, 1, 1, 0, 0}, // 0
  {0, 1, 1, 0, 0, 0, 0, 0}, // 1
  {1, 1, 0, 1, 1, 0, 1, 0}, // 2
  {1, 1, 1, 1, 0, 0, 1, 0}, // 3
  {0, 1, 1, 0, 0, 1, 1, 0}, // 4
  {1, 0, 1, 1, 0, 1, 1, 0}, // 5
  {1, 0, 1, 1, 1, 1, 1, 0}, // 6
  {1, 1, 1, 0, 0, 0, 0, 0}, // 7
  {1, 1, 1, 1, 1, 1, 1, 0}, // 8
  {1, 1, 1, 1, 0, 1, 1, 0}  // 9
};

int counter = 0; 
unsigned long previousMillis = 0;
const long interval = 1000; 

void setup() {
 
  for (int i = 0; i < 8; i++) {
    pinMode(segmentPins[i], OUTPUT);
    digitalWrite(segmentPins[i], LOW);
  }


  for (int i = 0; i < 4; i++) {
    pinMode(digitPins[i], OUTPUT);
    digitalWrite(digitPins[i], HIGH); 
  }
}

void loop() {
  unsigned long currentMillis = millis();

  
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    counter++;
    if (counter > 9999) counter = 0;
  }

  displayNumber(counter);
}


void displayNumber(int num) {
  int digits[4];
  digits[0] = num / 1000;
  digits[1] = (num / 100) % 10;
  digits[2] = (num / 10) % 10;
  digits[3] = num % 10;

  for (int i = 0; i < 4; i++) {
    for (int j = 0; j < 4; j++) {
      digitalWrite(digitPins[j], HIGH);
    }
    for (int seg = 0; seg < 8; seg++) {
      digitalWrite(segmentPins[seg], digitPatterns[digits[i]][seg]);
    }
    digitalWrite(digitPins[i], LOW);
    delay(5);
  }
}