【资源下载】下载地址如下1505：
https://docs.qq.com/doc/DTlRSd01BZXNpRUxl

#include <reg51.h>
		#include <math.h>
		sbit switch1=P0^0;
		sbit switch2=P0^1;
		sbit switch3=P0^2;
		 void delay_ms(unsigned int i)
		 {
		 unsigned char j;
		 for(;i>0;i--)
		 for(j=0;j<125;j++);
		  }
		 
		 void main()
		 {
		  EA=1;
		  TMOD=0x20;
		  TL1=0xfd;
		  TH1=0xfd;
		  PCON=0x00;
		  SCON=0xd0;
		  TR1=1;
		  ES=1;
		  SBUF=0xff;
		  while(TI==0);
		  TI=0;
		  while(1)
		  {
		   delay_ms(100);
		   if(switch1==0)
		   {
		   TB8=1;
		   SBUF=0x01;
		   while(TI==0);
		   TI=0;
		   TB8=0;
		   SBUF=0x00;
		   while(TI==0);
		   TI=0;