const int segmentPins[7] = {12, 13, 14, 15, 16, 17, 18};  

const int digitPatterns[10][7] = {
  {1, 1, 1, 1, 1, 1, 0},   
  {0, 0, 0, 0, 1, 1, 0},   
  {1, 1, 0, 1, 1, 0, 1},   
  {1, 1, 1, 1, 0, 0, 1},   
  {0, 1, 1, 0, 0, 1, 1},   
  {1, 0, 1, 1, 0, 1, 1},   
  {1, 0, 1, 1, 1, 1, 1},   
  {1, 1, 1, 0, 0, 0, 0},   
  {1, 1, 1, 1, 1, 1, 1},   
  {1, 1, 1, 0, 0, 1, 1}    
};

int currentDigit = 1;  

void setup() {
  for (int i = 0; i < 7; i++) {
    pinMode(segmentPins[i], OUTPUT);  
  }
}

void loop() {
  displayDigit(currentDigit);  
  
  delay(1000);
  
  currentDigit++;
  if (currentDigit > 9) {
    currentDigit = 1;
  }
}

void displayDigit(int digit) {
  
  for (int i = 0; i < 7; i++) {
    digitalWrite(segmentPins[i], !digitPatterns[digit][i]);
  }
}