原创 51学习4~~矩阵键盘

#include<reg52.h>
#define uint unsigned int
#define uchar unsigned char

uchar code table[]={
0xc0,0xf9,0xa4,0xb0,
0x99,0x92,0x82,0xf8,
0x80,0x90,0x88,0x83,
0xc6,0xa1,0x86,0x8e,0};
uchar num,temp,num1;
void delay(uint z)
{
uint x,y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}
uchar keyscan();
void display(uchar aa);
void main()
{
num=17;
P0=0;
P1=0xf8;
while(1)
{
display(keyscan());
}
}
void display(uchar aa)
{
P0=table[aa-1];
P1=0xf8;
}
uchar keyscan()
{
P2=0xfe;
temp=P2;
temp=temp&0xf0;     看高四位有没有置0
while(temp!=0xf0)
{
delay(5);
temp=P2;
temp=temp&0xf0;
while(temp!=0xf0)
{
temp=P2;
switch(temp)
{
case 0xee:num=1;
break;
case 0xde:num=2;
break;
case 0xbe:num=3;
break;
case 0x7e:num=4;
break;
}
while(temp!=0xf0)    有空试一下没有这三句会怎样
{
temp=P2;
temp=temp&0xf0;
}
}
}

P2=0xfd; /1111 1101
temp=P2;
temp=temp&0xf0;
while(temp!=0xf0)
{
delay(5);
temp=P2;
temp=temp&0xf0;
while(temp!=0xf0)
{
temp=P2;
switch(temp)
{
case 0xed:num=5;
break;
case 0xdd:num=6;
break;
case 0xbd:num=7;
break;
case 0x7d:num=8;
break;
}
while(temp!=0xf0)
{
temp=P2;
temp=temp&0xf0;
}
}
}


P2=0xfb;
temp=P2;
temp=temp&0xf0;
while(temp!=0xf0)
{
delay(5);
temp=P2;
temp=temp&0xf0;
while(temp!=0xf0)
{
temp=P2;
switch(temp)
{
case 0xeb:num=9;
break;
case 0xdb:num=10;
break;
case 0xbb:num=11;
break;
case 0x7b:num=12;
break;
}
while(temp!=0xf0)
{
temp=P2;
temp=temp&0xf0;
}
}
}


P2=0xf7;
temp=P2;
temp=temp&0xf0;
while(temp!=0xf0)
{
delay(5);
temp=P2;
temp=temp&0xf0;
while(temp!=0xf0)
{
temp=P2;
switch(temp)
{
case 0xe7:num=13;
break;
case 0xd7:num=14;
break;
case 0xb7:num=15;
break;
case 0x77:num=16;
break;
}
while(temp!=0xf0)
{
temp=P2;
temp=temp&0xf0;
}
}
}
return num;

}