#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);	
}