const byte _7SegCodeA[10] = {0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f};
const byte _7SegPinA[8] = {12, 14, 27, 26, 25, 33, 32, 13};
const byte _7SegPinB[8] = {4, 16, 17, 5, 18, 19, 21, 2};
int dig2 = 0;

void setup() {
  // put your setup code here, to run once:
  int i;
  Serial.begin(115200);
  for (i = 0; i < 8; i++) {
    pinMode(_7SegPinA[i], OUTPUT);
    pinMode(_7SegPinB[i], OUTPUT);
  }
  digitalWrite(_7SegPinB[7], HIGH);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int cnt = 0; cnt < 10; cnt++) {
    // for units digit.
    for (int seg = 0; seg < 8 ; seg++) {
      digitalWrite(_7SegPinA[seg], (_7SegCodeA[cnt] >> seg) & 0x01);
    }
    // for tens digit.
    for (int seg = 0; seg < 7 ; seg++) {
      digitalWrite(_7SegPinB[seg], (_7SegCodeA[dig2] >> seg) & 0x01);
    }
    Serial.println(cnt);
    delay(1000);
  }
  dig2++;
  if (dig2 == 10) {
    dig2 = 0;
  } 
}