void setup() {
  Serial.begin(115200);
  for (int i = 12; i <= 18; i++) {
    pinMode(i, OUTPUT);
  }
}
byte bitdigit[10] = {
  0x40,//0
  10011001,//1
  11000100,//2
  10110000,//3
  10111001,//4
  10101010,//5
  10011010,//6
  11111000,//7
  10000000,//8
  10010000 //9
};
void loop() {
  for (int k = 9; k >= 0; k--) {
    for (int i = 12; i <= 18; i++) {
      digitalWrite(i, bitRead(bitdigit[k], i - 12));
    }
    delay(1000);
  }
}