此程序在STC89C52上實驗通過！
晶振11.05926，
占用資源，外部中斷1，
LCD1602，顯示解碼！
串口通訊波特率4800KBS；
閆偉東，提示，在中端中不可以用while(p3_2);
否則，不能順利跳出終端！

#include <AT89X52.H>
#include "LCD.h"

#define uchar  unsigned char 
#define uint unsigned int  

//void Delay(unsigned int i);
void chuangkou(void);
void unint0 (void);
void senddata(unsigned char outdata);
unsigned char yandata[]=
 {
 '0',
 '1',
 '2',
 '3',
 '4',
 '5',
 '6',
 '7',
 '8',
 '9',
 'A',
 'B',
 'C',
 'D',
 'E',
 'F'
 };
unsigned char Iid[4]={0,0,0,0};
void main(void)
{ 
 LCD1602();
 Init_Lcd();
 unint0();
 chuangkou();
 
 P3_2=1; 
 senddata('1');
  while(1)
 {
  Display_LCD_Byte(0,0,'I');
  Display_LCD_Byte(0,1,'D');
  Display_LCD_Byte(0,2,':');
  Display_LCD_Byte(0,5,'0');
  Display_LCD_Byte(0,6,'X');

     Display_LCD_Byte(0,7,yandata[ Iid[0] / 16] );
  Display_LCD_Byte(0,8,yandata[ Iid[0] % 16] );

  Display_LCD_Byte(1,0,'D');
  Display_LCD_Byte(1,1,'A');
  Display_LCD_Byte(1,2,'T');
  Display_LCD_Byte(1,3,'A');
  Display_LCD_Byte(1,4,':');
  Display_LCD_Byte(1,5,'0');
  Display_LCD_Byte(1,6,'X');
  
  Display_LCD_Byte(1,7,yandata[ Iid[2] / 16] );
  Display_LCD_Byte(1,8,yandata[ Iid[2] % 16] );

 }
} 

/*void Delay(unsigned int i)
{
 while(-- i);
}*/

void chuangkou(void)
 {
 TMOD = 0X20;// JI SHU QI 1
 TH1=0XFA; //11.0592, 4800KPS
 TL1 =0XFA;
 TR1=1;  //QI DONG  
 SCON=0X50; //
 PCON=0X00; //BU JIA BEI
 }
void unint0 (void)
 {
 EA=1;
 EX0=1;
 IT0=1;
 }
void senddata(unsigned char outdata)
 {
 SBUF=outdata;
 while(!TI);
 TI=0; 
 }
void INT_0() interrupt 0 using 1
{
 unsigned char id[4]={0,0,0,0};
 unsigned char cishu0,cishu1,cishu2;
 EX0=0;
 for(cishu0=0;cishu0<10;cishu0++)
 {
 Delay(100);
 if(P3_2) goto exit;
 }
 if(!P3_2)
 {
 Delay(534);
 }
 while(!P3_2);//等待高電平 gou qu
 for(cishu1=0;cishu1< 4 ; cishu1 ++)
 {
 for(cishu2=0;cishu2 < 8 ; cishu2 ++)
 {
 while(!P3_2);//等待該gao電平開始延時，判斷高低
 Delay(90);
 if(P3_2)
  {
   id[cishu1]|= 0x01 << cishu2;
  Delay(100);
  //while(P3_2);在解碼時千萬不要有這樣的口令
  }
/* else
  {
  id[cishu1]&= 0xfe << cishu2;
  }*/
 }
 }
 if(id[0]!=~id[1]) goto exit;
 if(id[0]!=0x02) goto exit;
 if(id[2]!=~id[3]) goto exit;
 senddata(id[0]);
// senddata(id[1]);
 senddata(id[2]);//數據碼
// senddata(id[3]);//數據碼飯嗎
 for(cishu0=0;cishu0<200;cishu0++)
 {
 P2_0=~P2_0;
 Delay(50);
 }
 Iid[0]=id[0];
 Iid[2]=id[2];   
exit:
// while(!P3_2);
 EX0=1;
}