#include "STC89C51RC.H"

sbit DQ = P4^3;
sbit SPK = P1^0;

#include <absacc.h>

#define seg1 XBYTE[0xffec]
#define seg2 XBYTE[0xffed]
#define seg3 XBYTE[0xffee]
#define seg4 XBYTE[0xffef]
unsigned char IRMcode[4];

unsigned char code ledmap[]= //共陰LED數碼管譯碼表
{ 
 0x3f,0x06,0x5b,0x4f,0x66, //0,1,2,3,4,
 0x6d,0x7d,0x07,0x7f,0x6f, //5,6,7,8,9,  
 0x77,0x7C,0x39,0x5E,0x79, //A,b,C,d,E,
 0x71,      //F,
};

void delay(unsigned int);

void main()
{
 EA = 1;
 EX2 = 1;    
 while(1)
 {
 
  if (IRMcode[2]==~IRMcode[3]){  
   seg1 = ~ledmap[IRMcode[2]/100];
   seg2 = ~ledmap[IRMcode[2]/10%10];
   seg3 = ~ledmap[IRMcode[2]%10];
   seg4 = 0xff;//熄滅
  } 
 }
}

void Sound(void)
{
 SPK = 0;
 delay(10000);
 SPK = 1;
}

void IRMint(void) interrupt 6  using 2
{
 unsigned char count;
 unsigned int count1;
 unsigned char i,j; 
 EA = 0; 
 count = 9;
 while(--count)
 {
  delay(100);//440us
  if(DQ){EA = 1;return;}
 }
 while(DQ==0);//通過引導碼余下的低電平
 //以上完成引導碼4.5ms的低電平檢測
 
 count = 9;
 count1 = 0;
 while(--count)
 {
  delay(100);//440us
  if(DQ==0){EA = 1;return;}
 }
 while(DQ==1)//通過引導碼余下的高電平
 {
  if(count1++>1000) {
   P1=0x55;EA = 1;return;}
 }
 //以上完成引導碼4.5ms的高電平檢測
 
 count1 = 0;
 for(j=0;j<4;j++)//有效字節數設定
 {
  for(i=0;i<8;i++)//字節bit數
  {
   while(DQ==0);//通過編碼低電平
   delay(200);//延時判斷編碼高電平維持長度
   IRMcode[j]<<=1;
   if(DQ)IRMcode[j]|=0x01;
   while(DQ==1){//通過編碼余下的高電平
    if(count1++>2000){EA = 1;return;} 
   }
  }
 }
  
 Sound();  
 EA = 1;
}  

//通用延時函數
//22.1184,10 = 48.4 us (5us+43.4)
//22.1184,100 = 439 us (43.4*10+5)
//22.1184,1000 = 4345 us(43.4*100+5)
//22.1184,10000 = 43450 us(43.45*1000+5)
void delay(unsigned int t)
{     
 while(--t); 
}