recesive.c

汽车号牌识别系统

#include <AT89x051.H>
unsigned long check;
unsigned char ok;
unsigned char receivebits;
unsigned char receivebytes;
unsigned char recedata;
unsigned char start;

int i;
int j;

void main(void)
{
  check=0;
  SP=0X59;
  P3_0=1;       
  EX0=1;
  IT0=1; 
  EA=1;
  ok=0;


while(1)
{
P3_1=1;
P3_1=0;

if(ok==1)
	{
	
	 if((recedata&0x01)==0x01)
	   	   P3_3=0;
		  else
 		  P3_3=1;
 
	   if((recedata&0x02)==0x02)
	   	 P3_4=0;
		  else
 		  P3_4=1;
	   if((recedata&0x04)==0x04)
	   	   P3_5=0;
		   else
		   P3_5=1;

	   if((recedata&0x08)==0x08)
	       P3_7=0;
		   else
		   P3_7=1;

	      ok=0;

	}

}
}


receivedata() interrupt 0 using 3
{
if(start==0)
{
	check=check<<1;	
	if(P3_0==1)
		check++;
  	if(check==0x99887766)
   		start=1;
}
else
{
	receivebits++;
	recedata=recedata<<1;
	if(P3_0==1)
		recedata++;
	if(receivebits==8)
		{
			receivebits=0;
			start=0;
			ok=1;
		}

}
 
}