51单片机 矩阵按键的扫描、消抖、动作分离

#include

sbitADDR0=P1^0;

sbitADDR1=P1^1;

sbitADDR2=P1^2;

sbitADDR3=P1^3;

sbitENLED=P1^4;

sbitKEY_IN_1=P2^4;

sbitKEY_IN_2=P2^5;

sbitKEY_IN_3=P2^6;

sbitKEY_IN_4=P2^7;

sbitKEY_OUT_1=P2^3;

sbitKEY_OUT_2=P2^2;

sbitKEY_OUT_3=P2^1;

sbitKEY_OUT_4=P2^0;

codeunsignedcharLedChar[]={//数码管显示字符转换表

0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,

0x80,0x90,0x88,0x83,0xC6,0xA1,0x86,0x8E

};

unsignedcharKeySta[4][4]={//全部矩阵按键的当前状态

{1,1,1,1},

{1,1,1,1},

{1,1,1,1},

{1,1,1,1}

};

voidmain(){

unsignedchari,j;

unsignedcharbackup[4][4]={//按键值备份，保存前一次的值

{1,1,1,1},

{1,1,1,1},

{1,1,1,1},

{1,1,1,1}

};

EA=1;//使能总中断

ENLED=0;//选择数码管DS1进行显示

ADDR3=1;

ADDR2=0;

ADDR1=0;

ADDR0=0;

TMOD=0x01;//设置T0为模式1

TH0=0xFC;//为T0赋初值0xFC67，定时1ms

TL0=0x67;

ET0=1;//使能T0中断

TR0=1;//启动T0

P0=LedChar[0];//默认显示0

while(1){

for(i=0;i<4;i++){//循环检测4*4的矩阵按键

for(j=0;j<4;j++){

if(KeySta[i][j]!=backup[i][j]){//检测按键动作

if(KeySta[i][j]==0){//按键按下时执行动作

P0=LedChar[i*4+j];//将编号显示到数码管

}

backup[i][j]=KeySta[i][j];//更新前一次的备份值

}

}

}

}

}

/*T0中断服务函数，扫描矩阵按键状态并消抖*/

voidInterruptTimer0()interrupt1{

unsignedcharj;

staticunsignedchari=0;//矩阵按键扫描输出索引

staticunsignedcharkeybuf[4][4]={//矩阵按键扫描缓冲区

{0xFF,0xFF,0xFF,0xFF},

{0xFF,0xFF,0xFF,0xFF},

{0xFF,0xFF,0xFF,0xFF},

{0xFF,0xFF,0xFF,0xFF}

};

TH0=0xFC;//重新加载初值

TL0=0x67;

//将一行的4个按键值移入缓冲区

keybuf[i][0]=(keybuf[i][0]<<1)|KEY_IN_1;

keybuf[i][1]=(keybuf[i][1]<<1)|KEY_IN_2;

keybuf[i][2]=(keybuf[i][2]<<1)|KEY_IN_3;

keybuf[i][3]=(keybuf[i][3]<<1)|KEY_IN_4;

//消抖后更新按键状态

for(j=0;j<4;j++){//每行4个按键，所以循环4次

if((keybuf[i][j]&0x0F)==0x00){//连续4次扫描值为0，即4*4ms内都是按下状态时，可认为按键已稳定的按下

KeySta[i][j]=0;

}

elseif((keybuf[i][j]&0x0F)==0x0F){//连续4次扫描值为1，即4*4ms内都是弹起状态时，可认为按键已稳定的弹起

KeySta[i][j]=1;

}

}

//执行下一次的扫描输出

switch(i){//根据索引，释放当前输出引脚，拉低下次的输出引脚

case0:KEY_OUT_1=1;KEY_OUT_2=0;break;

case1:KEY_OUT_2=1;KEY_OUT_3=0;break;

case2:KEY_OUT_3=1;KEY_OUT_4=0;break;

case3:KEY_OUT_4=1;KEY_OUT_1=0;break;

default:break;

}

i=++i&0x03;

}