说明：  7通道解码程序提供51单片机的解码程序。可以实现任一通道的控制，程序简单，易懂，是作者花费很多精力设计而成。
(7-channel decoder to provide 51 single-chip decoder. Can control any channel, the program is simple, easy to understand, is the author designed to spend a lot of energy.)