keyscan.c

矩阵按键程序

#include<AT89X51.H>
#define uchar unsigned char
#define uint unsigned int
 uchar k=0; 
/////////////////////////////////延时
void delaynms(uint  n)
{uchar i;
while(n--)
        {for(i=0;i<125;i++);
        }
}
//////////////////////////////
uchar GetKey()
{uchar temp,key=0xff;
P2=0x0f;
temp=P2;
if(temp!=0x0f)
	{delaynms(50);
		temp=P2;
		if(temp!=0x0f)
			{	
			P2=0xef;
			temp=P2;
			switch (temp)
				{
				case 0xe7:key=0;break;
				case 0xeb:key=1;break;
				case 0xed:key=2;break;
				case 0xee:key=3;break;
				default:break;
				}

			P2=0xdf;
			temp=P2;
			switch (temp)
				{
				case 0xd7:key=4;break;
				case 0xdb:key=5;break;
				case 0xdd:key=6;break;
				case 0xde:key=7;break;
				default:break;
				}
	
			P2=0xbf;
			temp=P2;
			switch (temp)
				{
				case 0xb7:key=8;break;
				case 0xbb:key=9;break;
				case 0xbd:key=10;break;
				case 0xbe:key=11;break;
				default:break;
				}
	
			P2=0x7f;
			temp=P2;
			switch (temp)
				{
				case 0x77:key=12;break;
				case 0x7b:key=13;break;
				case 0x7d:key=14;break;
				case 0x7e:key=15;break;
				default:break;
				}
			while(P2&0x0f!=0x0f)
			{;}

			if (key!=0xff) ;
		
			}
	}
	return key;
}

void KeyProcess()
{uchar key=0xff;
key=GetKey();

if(P1==0x8f&&k==1)

{P0_0=0;
P3_7=0;
delaynms(3000);
}
 else if(P1==0x4f&&P0_5==0)
{P3_7=0;
P0_1=0;
delaynms(3000);
}
else if(P1==0x2f&&P0_6==0)
{P3_7=0;
P0_2=0;
delaynms(3000);
}
else if(P1==0x1f&&P0_7==0)
{P3_7=0;
P0_3=0;
delaynms(3000);
}

else if(key==0)
{k++;
if(k==1)P0_4=0;

else if(k==2)P0_4=1;
else 	if (k>2)k=0;
}
else if(key==1)P0_1=~P0_1;
else if(key==2)P0_2=~P0_2;
else if(key==3)P0_3=~P0_3;
else if(key==4)P0_4=~P0_4;
else if(key==5)P0_5=~P0_5;
else if(key==6)P0_6=~P0_6;
else if(key==7)P0_7=~P0_7;
else if(key==8){P0_0=~P0_0;P0_1=~P0_1;}
else if(key==9){P0_1=~P0_1;P0_2=~P0_2;}
else if(key==10){P0_2=~P0_2;P0_3=~P0_3;}
else if(key==11){P0_3=~P0_3;P0_4=~P0_4;}
else if(key==12){P0_4=~P0_4;P0_5=~P0_5;}
else if(key==13){P0_5=~P0_5;P0_6=~P0_6;}
else if(key==14){P0_6=~P0_6;P0_7=~P0_7;}
else if(key==15)P0=~P0;
}

/////////////////////////
main()
{
 while(1)
KeyProcess();
 }