//       A
//      ---
//  F |  G  | B
//      ---
//  E |     | C
//      ---
//       D

//dp A B C D E F G
int segmentPins[] = {13, 12, 14, 27, 26, 25, 33, 32};

const byte seg_7[10] = {  // 記錄0~9的七段數字
  B01111110,
  B00110000,
  B01101101,
  B01111001,
  B00110011,
  B01011011,
  B01011111,
  B01110000,
  B01111111,
  B01110011
};

void display_seg(int num) {
  for (int i = 0; i < 8; i++) {
    digitalWrite(segmentPins[i], (seg_7[num] << i & 0x80) >> 7);
  }
}

void setup() {
  Serial.begin(115200);
  for (int gpio = 0; gpio < 8; gpio++) {
    pinMode(segmentPins[gpio], OUTPUT);
  }
}

void loop() {
    int rand_num = random(0,10);
    display_seg(rand_num);
    delay(500);
    
}