按键控制定时器选播多段音乐,由51单片机控制，包括源程序和仿真图。-Anycast music key control timer from 51 single-chip control, including source code and simulation plan.

AT89C52定时控制继电器，用定时器0可以试验任意时间的定时，最短为1分钟，当然可以更改-AT89C52 timing control relays, can test the timing of the arbitrary time with the timer 0, minimum 1 minute, of course, can be changed

RFID 　设定定时器长度 经过测试 很好用 大家可以试一下-RFID set timeout length