制作一个基于AT89S52单片机的定时炸弹，包含程序设计的源代码，PCB图。-AT89S52 microcontroller based on making a time bomb, the source code of programming, PCB map.

本程序基于51单片机C语言。利用蜂鸣器可实现效果： 影片里可以听到的定时弹快要爆炸时定时器发出的声音-The program is based on 51 single-chip C language. Effect can be achieved using a buzzer: Timer issued when the film can hear the sound of timed bomb about to explode

通过 调节循环中的延时量，改变蜂鸣器的频率，效果是影片里可以听到的定时弹快要爆炸时定时器发出的声音-By adjusting the delay through the cycle of change, the buzzer frequency, the effect is timing bomb in the film is about to explode when the timer can be heard the sound of