这是一个基于51单片机的继电器控制程序。在主函数循环里用switch语句实现状态机的切换，在定时中断里累计中断次数，这两个的结合的框架思想。-This is a 51 singlechip microcomputer relay based control program. To realize the switching state machine with the switch statement in the main function in the timer interrupt cyc