4x4的矩阵键盘鬼键51单片机示例
时间: 2023-10-21 18:03:57 浏览: 54
以下是一个基于鬼键51单片机的4x4矩阵键盘的示例程序:
```c
#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
sbit ROW1 = P2^0;
sbit ROW2 = P2^1;
sbit ROW3 = P2^2;
sbit ROW4 = P2^3;
sbit COL1 = P2^4;
sbit COL2 = P2^5;
sbit COL3 = P2^6;
sbit COL4 = P2^7;
uchar code KEYCODE[4][4]={
{'1','2','3','A'},
{'4','5','6','B'},
{'7','8','9','C'},
{'*','0','#','D'}
};
uchar key_scan(){
uchar value=0xff;
ROW1 = 0;
if(COL1 == 0){value = 0;}
if(COL2 == 0){value = 1;}
if(COL3 == 0){value = 2;}
if(COL4 == 0){value = 3;}
ROW1 = 1;
ROW2 = 0;
if(COL1 == 0){value = 4;}
if(COL2 == 0){value = 5;}
if(COL3 == 0){value = 6;}
if(COL4 == 0){value = 7;}
ROW2 = 1;
ROW3 = 0;
if(COL1 == 0){value = 8;}
if(COL2 == 0){value = 9;}
if(COL3 == 0){value = 10;}
if(COL4 == 0){value = 11;}
ROW3 = 1;
ROW4 = 0;
if(COL1 == 0){value = 12;}
if(COL2 == 0){value = 13;}
if(COL3 == 0){value = 14;}
if(COL4 == 0){value = 15;}
ROW4 = 1;
return value;
}
void main(){
uchar keycode;
uchar lastkeycode = 0xff;
while(1){
keycode = key_scan();
if(keycode != lastkeycode){
if(keycode != 0xff){
P1 = KEYCODE[keycode/4][keycode%4];
}
lastkeycode = keycode;
}
}
}
```
这个程序通过读取矩阵键盘的行、列状态来确定按下的按键,并将对应的字符输出到P1端口。需要注意的是,矩阵键盘的行、列引脚需要通过外部电路连接到单片机的IO口。