scan.c

矩阵键盘串口发送与接受

 #include <reg51.h>
 #define  uint unsigned int
 #define  uchar unsigned char
 #define  key	P1 

char getkey()
{
   uchar a,b;
do
 {		
  key=0xf0;
  a=key;
  key=0x0f;
  b=key;
  a=a|b;
  		}
  while(a==0xff) ;
  return a;
}
char scan()
 {
 	uchar  i,a,n=0; 
 	uchar shu[]={0xee,0xde,0xbe,0x7e,0xed,0xdd,0xbd,0x7d,0xeb,0xdb,0xbb,0x7b,0xe7,0xd7,0xb7,0x77};
	a=getkey();
 	for(i=0;i<16;i++)
	{
	if(shu[i]==a)
	n=i;	
	}
   return n;
 }