Arduino:错误:“abs"未在此范围内声明 [英] Arduino: error: 'abs' was not declared in this scope

问题描述

我正在开发一个需要 abs() 函数的 arduino 库:

I'm working on an arduino library needing the abs() function:

#include <math.h>
normTransFreq1 = abs(1.0);

错误:'abs' 未在此范围内声明

Error: 'abs' was not declared in this scope

由于 math.h 已经包含在 cpp 中，我完全不确定如何解决这个问题.新安装的 arduino 1.5.2 没有帮助.

As math.h is already included in the cpp I'm entirely unsure how to fix this problem. A new install of arduino 1.5.2 didn't help.

推荐答案

刚刚找到解决方案:

库不需要包含 math.h.相反，应该通过在头文件中添加以下内容来包含 Arduino.h:

Including math.h is not needed for the library. Instead, Arduino.h should be included by adding the following to the header file:

#if ARDUINO >= 100
  #include "Arduino.h"
#else
  #include "WProgram.h"
#endif

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