解决用vscode开发arduino时Serial未定义

在工作目录编辑c_cpp_properties.json文件
添加defines字段

{
    "configurations": [
        {
            "name": "Win32",
            "includePath": [
                "D:\Program Files (x86)\Arduino\tools\**",
                "D:\Program Files (x86)\Arduino\hardware\arduino\avr\**",
                "D:\Program Files (x86)\Arduino\hardware\tools\avr\avr\include",
                "D:\Program Files (x86)\Arduino\hardware\tools\avr\lib\gcc\avr\7.3.0\include",
                "D:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino"
            ],
            "forcedInclude": [
                "D:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino\Arduino.h"
            ],
            "intelliSenseMode": "msvc-x64",
            "defines": [
                "USBCON"
            ]
        }
    ],
    "version": 4
}