4、MAVLink通信实战：消息解析与封装、心跳包与系统状态、自定义消息扩展、串口与UDP通信
好，咱们进入正题。MAVLink 通信，说白了就是无人机和地面站之间的「对话协议」。你想想看，飞控板上的传感器数据、GPS坐标、电池电压，这些东西怎么传到你的地面站界面上？靠的就是 MAVLink。我最早接触这个协议的时候，也觉得它挺复杂，但摸透了之后发现，其实核心就四个字：解析与封装。
核心要点：MAVLink 是一种轻量级的消息协议，专为微型飞行器设计。它定义了消息的格式、ID、载荷以及校验方式。你只要按照这个格式打包数据，飞控就能读懂；反过来，飞控发来的数据，你按格式拆开，就能拿到具体数值。
4.1 消息解析与封装：从字节流到结构化数据
先说说解析。飞控通过串口或UDP发过来的是一串字节流，比如 FE 09 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 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