在串口通讯程序中，对于收到的数据包，经常需要从中提取需要的数据，以及如何处理校验等，在这篇文章里举两个例子予以说明。此文也适于其它通讯程序中对数据报文的处理。 -In the serial communication program, received packets, often need to extract the needed data, as well as how to deal with parity and so on, in this article, give two e