键盘（4乘4）.c

单片机＋4*4键盘

#include<AT89X51.h>
#define unchar unsigned char
#define unint unsigned int
unchar code table[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x77,0x7c,0x39,0x5e,0x79,0x71};	 //+-*/= on分别为2b,2d,2a,25,3d,0x71(F的代码）
void KeyScan();
void delay10ms(unsigned char time);
void Dispaly(unsigned char k);

unsigned char key,temp;

void main() //主程序
{
while(1)
{
KeyScan();
}
}

void KeyScan() //按键扫描子程序
{
P3=0xFF;
P3_0=0;	  //第a行为0
temp=P3;
temp&=0xF0;
if(temp!=0xF0)
{
delay10ms(1);
temp=P3;
temp&=0xF0;
if(temp !=0xF0)
{
  temp=P3;
  temp&=0xF0;

  switch(temp)
  {
  case 0xe0:
  key=7;break;
  case 0xd0:
  key=8;break;
  case 0xb0:
  key=9;break;
  case 0x70:
  key=13;break;
  }
  Dispaly(key);
}
}

P3=0xFF;
P3_1=0;	 //第b行为0
temp=P3;
temp&=0xF0;
if(temp !=0xF0)
{
delay10ms(1);
temp=P3;
temp&=0xF0;
if(temp !=0xF0)
{
  temp=P3;
  temp&=0xF0;

  switch(temp)
  {
  case 0xe0:
  key=4;break;
  case 0xd0:
  key=3;break;
  case 0xb0:
  key=5;break;
  case 0x70:
  key=12;break;
  }
  Dispaly(key);
}
}

P3=0xFF;
P3_2=0;	 //第c行为0
temp=P3;
temp&=0xF0;
if(temp !=0xF0)
{
delay10ms(1);
temp=P3;
temp&=0xF0;
if(temp !=0xF0)
{
  temp=P3;
  temp&=0xF0;

  switch(temp)
  {
  case 0xe0:
  key=1;break;
  case 0xd0:
  key=2;break;
  case 0xb0:
  key=3;break;
  case 0x70:
  key=11;break;
  }
  Dispaly(key);
}
}

P3=0xFF;
P3_3=0;	 //第d行为0
temp=P3;
temp&=0xF0;
if(temp !=0xF0)
{
delay10ms(1);
temp=P3;
temp&=0xF0;
if(temp !=0xF0)
{
  temp=P3;
  temp&=0xF0;

  switch(temp)
  {
  case 0xe0:
  key=15;break;
  case 0xd0:
  key=0;break;
  case 0xb0:
  key=14;break;
  case 0x70:
  key=10;break;

  }
  Dispaly(key);
}
}
}

//延时程序
void delay10ms(unsigned char time)
{
unsigned char a,b,c;
for(a=0;a<time;a++)
for(b=0;b<10;b++)
  for(c=0;c<120;c++)
  ;
}

void Dispaly(unsigned char k) //显示程序
{
P0=table[k];
P2_1=0;
}