//按键和键盘组合程序

//P3口键盘扫描，P0口LED显示

#include<reg51.h>

unsigned char table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07};/*定义LED段位码*/

unsigned char temp;/*定义键值变量*/

void delay(unsigned char time)/*扫描延时子程序*/

{

unsigned char i,j;

for(i=0;i<=20;i++)

for(j=0;j<=time;j++);

}

void init(void)/*初始化子程序*/

{

P0=0x00;

P3=0xff;

}

void display(unsigned char key)/*显示子程序*/

{

P0=table[key];

}

bit keyscan()/*键盘扫描子程序*/

{

temp="P3";

if(temp!=0x00)

return 1;

else

return 0;

}

unsigned char keyprocess()/*键盘处理子程序*/

{

unsigned char keyresult;

switch(temp)

{

case 0xfe:keyresult=0x00;break;

case 0xfd:keyresult=0x01;break;

case 0xfb:keyresult=0x02;break;

case 0xf7:keyresult=0x03;break;

case 0xef:keyresult=0x04;break;

case 0xdf:keyresult=0x05;break;

case 0xbf:keyresult=0x06;break;

case 0x7f:keyresult=0x07;break;

default:keyresult=0xff;break;

}

return keyresult;

}

int main()/*主程序*/

{

unsigned char keyout;

init();//初始化

for(;;)

{

if(keyscan()==1)//第一次扫描

delay(250);//延时重扫描

if(keyscan()==1)//第二次扫描

{

keyout="keyprocess"();//取扫描键值

display(keyout);//显示

}

}

}