89C51单片机44键盘应用实例程序设计(含硬件仿真电路图)

89c51单片机4*4键盘应用实例硬件仿真电路图如下：

程序如下（编译成功）：

#include"reg51.h"

#include"LCD1602.h"

#include"hardware.h"

char code tab[4][4]={ {'1','4','7','#'},

{'2','5','8','0'},

{'3','6','9','*'},

{'A','B','C','D'}}; //0到F的16个键植

void delay(unsigned char a)

{

unsigned char i;

while(a--)

for(i=100;i>0;i--)

;

}

char kbscan() //键盘扫描

{

unsigned char hang,lie,key;

if(P3!=0x0f)

delay(5);

if(P3!=0x0f)

{

switch(P3&0x0f)

{

case 0x0e:lie=0;break;

case 0x0d:lie=1;break;

case 0x0b:lie=2;break;

case 7:lie=3;break;

}

P3=0xf0;

P3=0xf0;

switch(P3&0xf0)

{

case 0xe0:hang=0;break;

case 0xd0:hang=1;break;

case 0xb0:hang=2;break;

case 0x70:hang=3;break;

}

P3=0x0f;

while(P3!=0x0f);

key=tab[hang][lie];

}

else

key=0;

return (key);

}

void main()

{

unsigned char temp;

LCD_initial();

LCD_prints("piaoling");

P3=0x0f;

P0=0xff;

while(1)

{

temp=kbscan();

if(temp!=0)

{

P0=temp;

LCD_set_position(0x40);

LCD_printc(temp);

}

}

}