内容:利用单片机控制4*4矩阵式键 盘，通过数码管显示。代码

以下是基于Arduino单片机的代码，可用于控制4*4矩阵式键盘并通过数码管显示按键的值：

// 定义矩阵键盘行、列引脚和数码管引脚
#define ROW_1 2
#define ROW_2 3
#define ROW_3 4
#define ROW_4 5
#define COL_1 6
#define COL_2 7
#define COL_3 8
#define COL_4 9
#define DIGIT_1 10
#define DIGIT_2 11

// 定义键盘矩阵
char keys[4][4] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

// 初始化数码管显示
void setupDigit() {
  pinMode(DIGIT_1, OUTPUT);
  pinMode(DIGIT_2, OUTPUT);
}

// 显示数字
void showDigit(int digit, int value) {
  // 数码管共阴极，所以需要取反
  byte digits[10] = {
    B11000000, // 0
    B11111001, // 1
    B10100100, // 2
    B10110000, // 3
    B10011001, // 4
    B10010010, // 5
    B10000010, // 6
    B11111000, // 7
    B10000000, // 8
    B10010000  // 9
  };
  digitalWrite(DIGIT_1, HIGH);
  digitalWrite(DIGIT_2, HIGH);
  if (digit == 1) {
    digitalWrite(DIGIT_1, LOW);
    digitalWrite(DIGIT_2, HIGH);
  } else if (digit == 2) {
    digitalWrite(DIGIT_1, HIGH);
    digitalWrite(DIGIT_2, LOW);
  }
  byte digitValue = digits[value];
  for (int i = 0; i < 8; i++) {
    digitalWrite(i + 12, bitRead(digitValue, i));
  }
}

// 初始化矩阵键盘
void setupKeyboard() {
  pinMode(ROW_1, OUTPUT);
  pinMode(ROW_2, OUTPUT);
  pinMode(ROW_3, OUTPUT);
  pinMode(ROW_4, OUTPUT);
  pinMode(COL_1, INPUT_PULLUP);
  pinMode(COL_2, INPUT_PULLUP);
  pinMode(COL_3, INPUT_PULLUP);
  pinMode(COL_4, INPUT_PULLUP);
}

// 获取键值
char getKeyValue() {
  char key = ' ';
  digitalWrite(ROW_1, LOW);
  digitalWrite(ROW_2, HIGH);
  digitalWrite(ROW_3, HIGH);
  digitalWrite(ROW_4, HIGH);
  if (digitalRead(COL_1) == LOW) {
    key = keys[0][0];
  } else if (digitalRead(COL_2) == LOW) {
    key = keys[0][1];
  } else if (digitalRead(COL_3) == LOW) {
    key = keys[0][2];
  } else if (digitalRead(COL_4) == LOW) {
    key = keys[0][3];
  }
  digitalWrite(ROW_1, HIGH);
  digitalWrite(ROW_2, LOW);
  digitalWrite(ROW_3, HIGH);
  digitalWrite(ROW_4, HIGH);
  if (digitalRead(COL_1) == LOW) {
    key = keys[1][0];
  } else if (digitalRead(COL_2) == LOW) {
    key = keys[1][1];
  } else if (digitalRead(COL_3) == LOW) {
    key = keys[1][2];
  } else if (digitalRead(COL_4) == LOW) {
    key = keys[1][3];
  }
  digitalWrite(ROW_1, HIGH);
  digitalWrite(ROW_2, HIGH);
  digitalWrite(ROW_3, LOW);
  digitalWrite(ROW_4, HIGH);
  if (digitalRead(COL_1) == LOW) {
    key = keys[2][0];
  } else if (digitalRead(COL_2) == LOW) {
    key = keys[2][1];
  } else if (digitalRead(COL_3) == LOW) {
    key = keys[2][2];
  } else if (digitalRead(COL_4) == LOW) {
    key = keys[2][3];
  }
  digitalWrite(ROW_1, HIGH);
  digitalWrite(ROW_2, HIGH);
  digitalWrite(ROW_3, HIGH);
  digitalWrite(ROW_4, LOW);
  if (digitalRead(COL_1) == LOW) {
    key = keys[3][0];
  } else if (digitalRead(COL_2) == LOW) {
    key = keys[3][1];
  } else if (digitalRead(COL_3) == LOW) {
    key = keys[3][2];
  } else if (digitalRead(COL_4) == LOW) {
    key = keys[3][3];
  }
  return key;
}

void setup() {
  setupDigit();
  setupKeyboard();
}

void loop() {
  // 读取键值并显示在数码管上
  char key = getKeyValue();
  if (key != ' ') {
    if (key >= '0' && key <= '9') {
      showDigit(1, key - '0');
    } else if (key >= 'A' && key <= 'D') {
      showDigit(1, key - 'A' + 10);
    }
  }
}

注意，以上代码只是一个示例，你需要根据自己的具体硬件和需要进行适当的修改和调整。