基于AT89S52设计的超声波测距电路，有4路距离警报灯和蜂鸣器报警电路，并有警报输出接口。资料，中包括程序源代码和原理图，其中原理图是用protel99做的。-AT89S52 based on the design of ultrasonic distance measurement circuit, a 4-way distance warning lights and buzzer alarm circuits, and alarm output interface. Information, including source code and schematics, which is schematic protel99 do.