'analogWrite' was not declared in this scope

这个错误通常出现在 Arduino 编程中，表示你正在尝试使用未定义的函数 `analogWrite()`。这个函数用于在 Arduino 板的 PWM 引脚上输出模拟信号。要解决这个错误，你需要确保你的代码中包含正确的库和头文件，并且在使用 `analogWrite()` 函数之前声明它。如果你已经包含了正确的库和头文件，但仍然出现这个错误，可能是因为你的代码中存在语法错误或其他问题。你可以仔细检查你的代码，或者尝试在 Arduino 官方论坛上寻求帮助。

相关问题

“analogWrite” was not declared in this scope

This error message typically occurs when you are trying to use the "analogWrite" function in Arduino, but it is not recognized by the program.

There are a few possible reasons why this might happen:

1. You may have misspelled the function name. Make sure that you have typed it correctly as "analogWrite" with proper capitalization.

2. You may not have included the necessary header file. In order to use the "analogWrite" function, you need to include the "Arduino.h" header file at the top of your program.

3. You may be using an older version of Arduino that does not support the "analogWrite" function. Check your version and make sure it is up to date.

4. You may be using the wrong pin number. The "analogWrite" function is used to output a PWM signal on certain pins that support it. Make sure that you are using one of these pins and that you have specified the correct pin number in your code.

Once you have identified the issue, you can take steps to correct it and get your program running properly.

error: 'analogWrite' was not declared in this scope

这个错误通常出现在 Arduino 代码中，是因为你在使用 `analogWrite` 函数之前没有在代码中包含 `analogWrite` 函数所在的库文件。`analogWrite` 函数通常在 `Arduino.h` 或 `WProgram.h` 库文件中定义，因此你需要在代码中添加如下代码：

#include <Arduino.h>

如果上述代码仍然无法解决问题，可能是因为你的 Arduino 板子不支持 `analogWrite` 函数。在这种情况下，你需要查看你的板子的规格说明，以确定它是否支持模拟输出。