使用 Arduino 的摩尔斯电码答案

【问题标题】：Morse Code with Arduino使用 Arduino 的摩尔斯电码
【发布时间】：2017-12-23 17:10:03
【问题描述】：

我正在学习编写 Arduino 代码，为此，我尝试用英语制作一个摩尔斯电码转换器。这是我的代码，我面临以下问题：

   Arduino: 1.8.5 (Windows 10), Board: "Arduino/Genuino Uno"

C:\Users\Kunal Gehlot\OneDrive\Documents\Arduino\Morse_CODE\Morse_CODE.ino: In function 'void setup()':

Morse_CODE:16: error: request for member 'length' in 'in', which is of non-class type 'char [28]'

   for (int i = 0; i < in.length; i++) {

                          ^

Morse_CODE:18: error: request for member 'lentgh' in 'in', which is of non-class type 'char [28]'

   n = in.lentgh[i];

          ^

exit status 1
request for member 'length' in 'in', which is of non-class type 'char [28]'

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

这是我的代码：

int Speaker1 = 4;
int Speaker2 = 6;
int LED = 2;
int Relay = 12;
char n = 0;
char in[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ ";

void setup() {
  pinMode(Speaker1, OUTPUT);
  pinMode(Speaker2, OUTPUT);
  pinMode(LED, OUTPUT);
  pinMode(Relay, OUTPUT);
  for (int i = 0; i < in.length; i++) {
    n = in.lentgh[i];
    switch (n) {
      case 'A' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'B' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'C' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'D' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'E' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'F' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'G' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'H' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'I' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'J' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'K' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'L' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'M' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'N' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'O' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'P':
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'Q':
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'R':
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'S':
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'T':
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'U':
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'V':
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'W':
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'X':
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'Y':
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case 'Z':
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
      case ' ' :
        delay (700);
        break;
    }
  }
}

void loop() {
}

我对这个项目的唯一目标是从串行监视器中获取输入文本并将其分解为每个单独的字母，我还将在列表中添加符号并将其转换为 LED 中的摩尔斯电码，继电器用于电脉冲和扬声器。

【问题讨论】：

你从哪里得到length？ in.lentgh[i] 应该做什么？
请不要将问题固定为答案，否则新读者很难看出问题所在。正如您所做的那样，添加答案是正确的方法。谢谢！
注意到并抱歉，会注意的

标签： string arduino

【解决方案1】：

正如其他人在 cmets 中指出的那样，您应该使用 strlen() 来查找 Arduino 中字符数组的长度。 strlen() 是标准 Arduino 库的一部分，因此您无需添加任何特殊的#include 语句即可使用它。

如果您使用 sizeof(in)，代码将发送缓冲区中的每个字符，即使您感兴趣的字符串小于缓冲区。

例如，假设 in[] = "ABC"; sizeof(in) 错误地返回 4，因为 "ABC" 在 'C' 字符之后有一个隐藏的 0 字节。 strlen(in) 在这种情况下返回 3，即正确的数字。

所以，

for (int i = 0; i

应该是

for (int i = 0; i

【讨论】：

【解决方案2】：

而不是使用 in.lentgh[i]，sizeof(in) 应该用于 for 循环的条件。

已解决的代码：

int Speaker1 = 4;
int Speaker2 = 6;
int LED = 2;
int Relay = 12;
char n = '0';
char in[]= "ABCDEFGHIJKLMNOPQRSTUVWXYZ ";

void setup() {

  pinMode(Speaker1, OUTPUT);
  pinMode(Speaker2, OUTPUT);
  pinMode(LED, OUTPUT);
  pinMode(Relay, OUTPUT);

  for (int i = 0; i < sizeof(in); i++) {
  delay (1200);
  n = in[i];

    switch (n) {

case 'A' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'B' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'C' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'D' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'E' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'F' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'G' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'H' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'I' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'J' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'K' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'L' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'M' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'N' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'O' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'P' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'Q' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'R' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'S' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'T' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'U' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'V' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'W' :
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'X' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'Y' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case 'Z' :
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(300);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(100);
        digitalWrite(Speaker1, HIGH);
        delay(100);
        digitalWrite(Speaker1, LOW);
        delay(300);
        break;
case ' ' :
        delay (700);
        break;
    }


  }


}

void loop() {

}

【讨论】：

sizeof 是缓冲区的大小，不一定是字符串的长度。使用strlen。
没关系。