8只数码管滚动显示数字串

以下是使用Arduino编程实现的8位数码管滚动显示数字串的代码：

// 定义数码管引脚
int segA = 2;
int segB = 3;
int segC = 4;
int segD = 5;
int segE = 6;
int segF = 7;
int segG = 8;
int segDP = 9;

// 定义数字串
char digits[] = "12345678";

void setup() {
  // 设置数码管引脚为输出
  pinMode(segA, OUTPUT);
  pinMode(segB, OUTPUT);
  pinMode(segC, OUTPUT);
  pinMode(segD, OUTPUT);
  pinMode(segE, OUTPUT);
  pinMode(segF, OUTPUT);
  pinMode(segG, OUTPUT);
  pinMode(segDP, OUTPUT);
}

void loop() {
  // 循环显示数字串
  for (int i = 0; i < 8; i++) {
    // 显示当前数字
    showDigit(digits[i]);
    // 延时
    delay(500);
    // 关闭数码管
    clearDisplay();
  }
}

// 显示数字
void showDigit(char digit) {
  switch (digit) {
    case '0':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, LOW);
      digitalWrite(segDP, LOW);
      break;
    case '1':
      digitalWrite(segA, LOW);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, LOW);
      digitalWrite(segE, LOW);
      digitalWrite(segF, LOW);
      digitalWrite(segG, LOW);
      digitalWrite(segDP, LOW);
      break;
    case '2':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, LOW);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, LOW);
      digitalWrite(segG, HIGH);
      digitalWrite(segDP, LOW);
      break;
    case '3':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, LOW);
      digitalWrite(segF, LOW);
      digitalWrite(segG, HIGH);
      digitalWrite(segDP, LOW);
      break;
    case '4':
      digitalWrite(segA, LOW);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, LOW);
      digitalWrite(segE, LOW);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, HIGH);
      digitalWrite(segDP, LOW);
      break;
    case '5':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, LOW);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, LOW);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, HIGH);
      digitalWrite(segDP, LOW);
      break;
    case '6':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, LOW);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, HIGH);
      digitalWrite(segDP, LOW);
      break;
    case '7':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, LOW);
      digitalWrite(segE, LOW);
      digitalWrite(segF, LOW);
      digitalWrite(segG, LOW);
      digitalWrite(segDP, LOW);
      break;
    case '8':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, HIGH);
      digitalWrite(segDP, LOW);
      break;
    case '9':
      digitalWrite(segA, HIGH);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, LOW);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, HIGH);
      digitalWrite(segDP, LOW);
      break;
  }
}

// 关闭数码管
void clearDisplay() {
  digitalWrite(segA, LOW);
  digitalWrite(segB, LOW);
  digitalWrite(segC, LOW);
  digitalWrite(segD, LOW);
  digitalWrite(segE, LOW);
  digitalWrite(segF, LOW);
  digitalWrite(segG, LOW);
  digitalWrite(segDP, LOW);
}

这段代码使用了一个字符数组来存储数字串，在`loop()`函数中循环显示数字串的每一个字符，使用`showDigit()`函数将当前字符显示在数码管上，然后使用`delay()`函数延时一段时间后关闭数码管。`showDigit()`函数根据传入的字符显示对应的数字，使用了数字位的控制方法。`clearDisplay()`函数用来关闭数码管。