红外一开始发送一段13。5ms的引导码，引导码由9ms的高电平和4。5ms的低电平组成，跟着
引导码是系统码，系统反码，按键码，按键反码，如果按着键不放，则遥控器则发送一段重
复码，重复码由9ms的高电平，2。25ms的低电平，跟着是一个短脉冲，本程序是免费给大
家，版权所有，不得用于商业目的，如需用到本程序到商业上请与本人联系
jiang_xi_sheng@163.com，经本人同意后方可用于商业目的，本程序经过试用，能解大部分

遥控器的编码！

#include    "at89x52.h"
#define     NULL       0x00//数据无效
#define     RESET      0X01//程序复位
#define     REQUEST    0X02//请求信号
#define     ACK        0x03//应答信号，在接收数据后发送ACK信号表示数据接收正确，
也位请求信号的应答信号
#define     NACK       0x04//应答信号，表示接收数据错误
#define     BUSY       0x05//忙信号，表示正在忙
#define     FREE       0x06//空闲信号，表示处于空闲状态
#define     READ_IR    0x0b//读取红外
#define     STORE_IR   0x0c//保存数据
#define     READ_KEY   0x0d//读取键值
#define     RECEIVE    0Xf400//接收缓冲开始地址
#define     SEND       0xfa00//发送缓冲开始地址
#define     IR         0x50//红外接收缓冲开始地址
#define     HEAD       0xaa//数据帧头
#define     TAIL       0x55//数据帧尾
#define     SDA        P1_7
#define     SCL        P1_6



unsigned char xdata *buf1;  //接受数据缓冲
unsigned int  buf1_length;  //接收到的数据实际长度
unsigned char xdata *buf2;  //发送数据缓冲
unsigned int  buf2_length;  //要发送的数据实际长度
bit buf1_flag;    //接收标志，1表示接受到一个数据帧，0表示没有接受到数据帧或数据
帧为空
bit buf2_flag;    //发送标志，1表示需要发送或没发送完毕，0表示没有要发送的数据或
发送完毕
unsigned char state1,state2;         //用来标志接收字符的状态，state1用来表示接
收状态，state2用来表示发送状态
unsigned char data *ir;
union{
    unsigned char a[2];
    unsigned int b;
    unsigned char data *p1[2];
    unsigned int data *p2[2];
    unsigned char xdata *p3;    //红外缓冲的指针
    unsigned int xdata *p4;
}p;
//union{                       //
  //  unsigned char a[2];           //
  //  unsigned int b;
  //  unsigned char data *p1[2];
  //  unsigned int data *p2[2];
  //  unsigned char xdata *p3;
  //  unsigned int xdata *p4;       //地址指针
//}q;                        //

union{
   unsigned char a[2];
   unsigned int b;
}count;
union{
   unsigned char a[2];
   unsigned int b;
}temp;
union{
   unsigned char a[4];
   unsigned int b[2];
   unsigned long c;
}ir_code;

union{
   unsigned char a[4];
   unsigned int b[2];
   unsigned long c;
   unsigned char data *p1[4];
   unsigned int data *p2[4];
   unsigned char xdata *p3[2];
   unsigned int xdata *p4[2];
}i;
unsigned char ir_key;
bit ir_flag;        //红外接收标志，0为缓冲区空，1为接收成功，2为缓冲溢出
void sub(void);
void delay(void);
void ie_0(void);
void tf_0(void);
void ie_1(void);
void tf_1(void);
void tf_2(void);
void read_ir(void);
void ir_jiema(void);
void ir_init(void);
void ir_exit(void);
void store_ir(void);
void read_key(void);
void reset_iIC(void);
unsigned char read_byte_ack_iic(void);
unsigned char read_byte_nack_iic(void);
bit write_byte_iic(unsigned char a);
void send_ack_iic(void);
void send_nack_iic(void);
bit receive_ack_iic(void);
void start_iic(void);
void stop_iic(void);
void write_key_data(unsigned char a);
unsigned int read_key_data(unsigned char a);
void ie0(void)   interrupt 0{ie_0();}
void tf0(void)   interrupt 1{tf_0();}
void ie1(void)   interrupt 2{ie_1();}
void tf1(void)   interrupt 3{tf_1();tf_2();}
void tf2(void)   interrupt 5{            //采用中断方式跟查询方式相结合的办法解
码
   EA=0;                                 //禁止中断
   if(TF2){                              //判断是否是溢出还是电平变化产生的中断
        TF2=0;                           //如果是溢出产生的中断则清除溢出位，重
新开放中断退出
        EA=1;
        goto end;
    }
   EXF2=0;                               //清除电平变化产生的中断位
   *ir=RCAP2H;                            //把捕捉的数保存起来
   ir++;
   *ir=RCAP2L;
   *ir++;
   F0=1;
   TR0=1;                                 //开启计数器0
loop:
   TL0=0;  //将计数器0重新置为零
   TH0=0;
   while(!EXF2){                         //查询等待EXF2变为1
        if(TF0)goto exit;                //检查有没超时，如果超时则退出
   };
   EXF2=0;                               //将EXF2清零
   if(!TH0)                            //判断是否是长低电平脉冲过来了
   {                                     //不是长低电平脉冲而是短低电平
      if(F0)count.b++;                      //短脉冲数加一
      temp.a[0]=RCAP2H;                  //将捕捉数临时存放起来
      temp.a[1]=RCAP2L;
      goto loop;                         //返回继续查询
   }
   else{                                 //是低电平脉冲，则进行处理

       F0=0;
       *ir=temp.a[0];       //把连续的短脉冲总时间记录下来
       ir++;
       *ir=temp.a[1];
       ir++;
       *ir=RCAP2H;          //把长电平脉冲时间记录下来
       ir++;
       *ir=RCAP2L;
       ir++;
       if(ir>=0xda) {
                 goto exit;    //判断是否溢出缓冲，如果溢出则失败退出
       }
       goto loop;         //返回继续查询
       }
exit:
       ir_flag=1;       //置ir_flag为1表示接收成功
end:
       ;
}


void rs232(void)   interrupt  4{
     static unsigned char sbuf1,sbuf2,rsbuf1,rsbuf2;      //sbuf1,sbuf2用来接收
发送临时用，rsbuf1,rsbuf2用来分别用来存放接收发送的半字节
     EA=0;                                         //禁止中断
     if(RI){
         RI=0;                                     //清除接收中断标志位
         sbuf1=SBUF;                               //将接收缓冲的字符复制到sbuf1
         if(sbuf1==HEAD){                                  //判断是否帧开头
                         state1=10;                 //是则把state赋值为10
                         buf1=RECEIVE;              //初始化接收地
址                        
         }
         else{
         switch(state1){
         case 10:sbuf2=sbuf1>>4;                   //把高半字节右移到的半字节
                 sbuf2=~sbuf2;                     //把低半字节取反
                 if((sbuf2&0x0f)!=(sbuf1&0x0f))    //判断接收是否正确
                      {                            //接收错误，有可能接收的是数
据帧尾，也有可能是接收错误
                       if(sbuf1==TAIL)             //判断是否接收到数据帧尾
                            {                      //是接收到数据帧尾
                                buf1=RECEIVE;      //初始化接收的地址
                                if(*buf1==RESET)   //判断是否为复位命令
                                     {
                                        ES=0;
                                        sbuf2=SP+1;
                                        for(p.p1[0]=SP-0x10;p.p1[0]<=sbuf2;p.p1
[0]++)*p.p1[0]=0;
                                     }
                                state1=0;          //将接收状态标志置为零，接收
下一个数据帧
                                buf1_flag=1;       //置接收标志为1，表示已经接收
到一个数据帧
                                REN=0;             //禁止接收
                            }
                       else
                           {                       //不是接受到数据帧尾，表明接
收错误
                               state1=0;           // 将接收状态标志置为零，重新
接收
                               buf1=RECEIVE;       //初始化发送的地址
                               *buf1=NACK;         //把NACK信号存入接收缓冲里
                               buf1_flag=1;        //置标志位为1，使主程序能对接
收错误进行处理
                               REN=0;              //禁止接收
                           }

                      }
                 else
                 {                                 //接收正确
                     rsbuf1=~sbuf1;                //按位取反，使高半字节变原码
                     rsbuf1&=0xf0;                 //仅保留高半字节，低半字节去
掉
                     state1=20;                    //将状态标志置为20，准备接收
低半字节
                 }
                 break;
         case 20:sbuf2=sbuf1>>4;                   //把高半字节右移到的半字节
                 sbuf2=~sbuf2;                     //将低半字节取反
                 if((sbuf2&0x0f)!=(sbuf1&0x0f))    //判断接收是否正确
                    {                              //接受错误
                        state1=0;                  // 将接收状态标志置为零，重新
接收
                        buf1=RECEIVE;              //初始化接收的地址
                        *buf1=NACK;                //把NACK信号存入发送缓冲里
                        buf1_flag=1;               //置标志位为1，使主程序能对接
收错误进行处理
                        REN=0;                     //禁止接收
                    }
                 else
                    {
                    sbuf1&=0x0f;                   //仅保留低半字节，去掉高半字
节
                    rsbuf1|=sbuf1;                 //高低半字节合并
                    *buf1++=rsbuf1;                //将接收的数据保存至接收缓冲
里,并且数据指针加一
                    buf1_length++;                 //接收数据长度加一
                    state1=10;                     //将state1置为10，准备接收下
个字节的高半字节
                    }
                 break;

         }
         }



     }
  else{

       TI=0;                                       //清除发送中断标志
       if(buf2_length)                             //判断发送长度是否为零
               {                                   //发送长度不为零
               if(state2==0)                       //判断是否发送高半字节
                   {                               //发送高半字节
                       sbuf2=*buf2;                //将要发送的字节送到sbuf2
                       rsbuf2=~sbuf2;              //取反，使高半字节变为反码
                       sbuf2>>=4;                  //将高半字节右移到低半字节
                       rsbuf2&=0xf0;               //保留高半字节，去掉低半字节
                       sbuf2&=0x0f;                //保留低半字节，去掉高半字节
                       rsbuf2|=sbuf2;              //合并高低半字节
                       SBUF=rsbuf2;                //发送出去
                       state2=10;                  //将state2置为10准备发送下半
字节
                    }
                else
                    {                              //发送低半字节
                       sbuf2=*buf2;                //将要发送的字节送到sbuf2
                       buf2++;                     //指针加一
                       buf2_length--;              //发送数据长度减一
                       rsbuf2=~sbuf2;              //取反，使低半字节变为反码
                       rsbuf2<<=4;                 //将低半字节反码左移到高半字
节
                       rsbuf2&=0xf0;               //保留高半字节，去掉低半字节
                       sbuf2&=0x0f;                //保留低半字节，去掉高半字节
                       rsbuf2|=sbuf2;              //合并高低半字节
                       SBUF=rsbuf2;                //发送出
                       state2=0;
                     }
                }
         else
                {                                  //如果发送数据长度为零则发送
数据帧尾
                    if(buf2_flag){                 //判断是否发过数据帧尾
                    SBUF=TAIL;                     //将数据帧尾发送出去
                    while(TI==0);
                    TI=0;
                    buf2_flag=0;                   //置发送标志为零，表示发送完
毕
                    }
                }
  }
  EA=1;                                             //开放中断
}