4×4矩阵键盘数码管显示 最简便易懂的键盘扫描方法

/////4×4矩阵键盘按键为1-16，按键显示0-

9、a-f；

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#include

52.h>

#define uchar unsigned char

uchar key=0;

uchar code

table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0x a1,0x86,0x8e,0xc0};

void show(uchar key){P0=table[key];//显示数值}void Scan_key()//扫描键盘{uchar m;

P1=0xff;//数码管全亮

P2=0x0f;//P2口赋初值低位1高位0

m=P2;

switch (m){case 0x0e:

{P2=0xf0;

m=P2;

switch (m){case 0xe0:{key=0;show(key);break;}

case 0xd0:{key=1;show(key);break;}

case 0xb0:{key=2;show(key);break;}

case 0x70:{key=3;show(key);break;}

default:

break;}break;}case 0x0d:

{P2=0xf0;

m=P2;

switch (m){case 0xe0:{key=4;show(key);break;} case 0xd0:{key=5;show(key);break;}

case 0xb0:{key=6;show(key);break;}

case 0x70:{key=7;show(key);break;}

default:

break;}break;}case 0x0b:

{P2=0xf0;

m=P2;

switch (m){case 0xe0:{key=8;show(key);break;} case 0xd0:{key=9;show(key);break;}

case 0xb0:{key=10;show(key);break;}

case 0x70:{key=11;show(key);break;} default:

break;}break;}case 0x07:{P2=0xf0;

m=P2;

switch (m){case 0xe0:{key=12;show(key);break;} case 0xd0:{key=13;show(key);break;}

case 0xb0:{key=14;show(key);break;} case 0x70:{key=15;show(key);break;} default:

break;}break;}default : break;}}

void main(){while

(1){Scan_Key();}}