51单片机程序——4乘4矩阵键盘使用方法

#define uint unsigned int

#define uchar unsigned char

#define dula P0

#define wela P1

unsigned char code DuanMa[]={0xc0,0xf9,0xa4,0xb0,

0x99,0x92,0x82,0xf8,

0x80,0x90,0x88,0x83,

0xa7,0xa1,0x86,0x8e,0xff};

uchar num,temp;

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=16;

while(1)

{

display(keyscan());

}

}

void display(uchar aa)

{

wela=0xff;

dula=DuanMa[aa];

}

uchar keyscan()

{

P2=0xef;

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f) //确认是否按下

{

delay(5);

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f)

{

temp=P2;

switch(temp)

{

case 0xee:num=0;

break;

case 0xed:num=1;

break;

case 0xeb:num=2;

break;

case 0xe7:num=3;

break;

}

while(temp!=0x0f) //松手检测

{

temp=P2;

temp=temp&0x0f;

}

}

}

P2=0xdf;

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f)

{

delay(5);

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f)

{

temp=P2;

switch(temp)

{

case 0xde:num=4;

break;

case 0xdd:num=5;

break;

case 0xdb:num=6;

break;

case 0xd7:num=7;

break;

}

while(temp!=0x0f)

{

temp=P2;

temp=temp&0x0f;

}

}

}

P2=0xbf;

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f)

{

delay(5);

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f)

{

temp=P2;

switch(temp)

{

case 0xbe:num=8;

break;

case 0xbd:num=9;

break;

case 0xbb:num=10;

break;

case 0xb7:num=11;

break;

}

while(temp!=0x0f)

{

temp=P2;

temp=temp&0x0f;

}

}

}

P2=0x7f;

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f)

{

delay(5);

temp=P2;

temp=temp&0x0f;

while(temp!=0x0f)

{

temp=P2;

switch(temp)

{

case 0x7e:num=12;

break;

case 0x7d:num=13;

break;

case 0x7b:num=14;

break;

case 0x77:num=15;

break;

}

while(temp!=0x0f)

{

temp=P2;

temp=temp&0x0f;

}

}

}

return num;

}