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 cycle, in the cumulative number of interrupts, the combination of the two framework of thought.