利用共阴级数码管实现(0~f)的数据循环

好的，这是一个简单的共阴极数码管循环显示0~F的程序，你可以参考下面的代码：

int num = 0; // 初始数字为0

void setup() {
  // 设置数码管引脚为输出模式
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
}

void loop() {
  // 数码管显示0~F的循环
  if (num < 16) {
    display(num);
    num++;
  } else {
    num = 0;
  }
  delay(500); // 延时500ms
}

void display(int num) {
  switch (num) {
    case 0:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, HIGH);
      break;
    case 1:
      digitalWrite(2, HIGH);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, HIGH);
      digitalWrite(6, HIGH);
      digitalWrite(7, HIGH);
      digitalWrite(8, HIGH);
      break;
    case 2:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, HIGH);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, HIGH);
      digitalWrite(8, LOW);
      break;
    case 3:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, HIGH);
      digitalWrite(7, HIGH);
      digitalWrite(8, LOW);
      break;
    case 4:
      digitalWrite(2, HIGH);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, HIGH);
      digitalWrite(6, HIGH);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 5:
      digitalWrite(2, LOW);
      digitalWrite(3, HIGH);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, HIGH);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 6:
      digitalWrite(2, LOW);
      digitalWrite(3, HIGH);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 7:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, HIGH);
      digitalWrite(6, HIGH);
      digitalWrite(7, HIGH);
      digitalWrite(8, HIGH);
      break;
    case 8:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 9:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, HIGH);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 10:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, HIGH);
      break;
    case 11:
      digitalWrite(2, LOW);
      digitalWrite(3, LOW);
      digitalWrite(4, HIGH);
      digitalWrite(5, HIGH);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 12:
      digitalWrite(2, HIGH);
      digitalWrite(3, HIGH);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 13:
      digitalWrite(2, LOW);
      digitalWrite(3, HIGH);
      digitalWrite(4, HIGH);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 14:
      digitalWrite(2, HIGH);
      digitalWrite(3, HIGH);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
    case 15:
      digitalWrite(2, HIGH);
      digitalWrite(3, HIGH);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, HIGH);
      digitalWrite(7, LOW);
      digitalWrite(8, LOW);
      break;
  }
}

需要注意的是，在共阴极数码管中，数字0~9需要点亮的LED灯是相同的，因此可以通过一个`display()`函数实现。函数中的`switch`语句用于根据数字选择对应的LED灯进行点亮。在主循环中，通过控制`num`变量的值实现0~F的循环。