矩阵按键

#include<reg52.h>

sbit ADDR0 = P1^0;
sbit ADDR1 = P1^1;
sbit ADDR2 = P1^2;
sbit ADDR3 = P1^3;
sbit ENLED = P1^4;

sbit KEY_IN_1 = P2^4;
sbit KEY_IN_2 = P2^5;
sbit KEY_IN_3 = P2^6;
sbit KEY_IN_4 = P2^7;
sbit KEY_OUT_1 = P2^3;
sbit KEY_OUT_2 = P2^2;
sbit KEY_OUT_3 = P2^1;
sbit KEY_OUT_4 = P2^0;

unsigned char code LedChar[]={
 0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8,
 0x80, 0x90, 0x88, 0x83, 0xC6, 0xA1, 0x86, 0x8E
 };
unsigned char KeySta[4][4] = {
 {1,1,1,1},{1,1,1,1},{1,1,1,1},{1,1,1,1}
 };
unsigned char LedBuff[6] = {
 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
 };
unsigned char code KeyCodeMap[4][4] = { //矩阵按键编号到标准键盘键码的映射表
    { 0x31, 0x32, 0x33, 0x26 }, //数字键1、数字键2、数字键3、向上键
    { 0x34, 0x35, 0x36, 0x25 }, //数字键4、数字键5、数字键6、向左键
    { 0x37, 0x38, 0x39, 0x28 }, //数字键7、数字键8、数字键9、向下键
    { 0x30, 0x1B, 0x0D, 0x27 }  //数字键0、ESC键、  回车键、 向右键
 };
void  KeyDriver();
void main()
{
    EA = 1;       //使能总中断
    ENLED = 0;    //选择数码管进行显示
    ADDR3 = 1;
    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
    LedBuff[0] = LedChar[0];  //上电显示0
 
    while (1)
    {
        KeyDriver();   //调用按键驱动函数
    }
}

void ShowNumber(unsigned long num)
{
 signed char i;
 unsigned char buf[6];

 for(i=0; i<6; i++)
 {
  buf[i] = num % 10;
  num = num / 10;
 }

 for(i=5; i>=1; i--)
 {
  if(buf[i] == 0)
  {
   LedBuff[i] = 0xFF;
  }
  else
   break;
 }
 
 for(; i>=0; i--)
 {
  LedBuff[i] = LedChar[buf[i]]; 
 }

}
void KeyAction(unsigned char keycode)
{
 static unsigned long result = 0;
 static unsigned long addend = 0;
 
 if((keycode >= 0x30) &&(keycode <= 0x39))
 {
  addend = (addend *10) + (keycode - 0x30);  
  ShowNumber(addend);
 }
 
 else if(keycode == 0x26)
 {
  result += addend;
  addend = 0;
  ShowNumber(result);
 }
 else if(keycode == 0x0D)
 {
  result += addend;
  addend = 0;
  ShowNumber(result);
 }
 else if(keycode == 0x1B)
 {
  addend = 0;
  result = 0;
  ShowNumber(addend);  
 } 
 
}
void  KeyDriver()
{
 unsigned char i, j;
 static unsigned char backup [4][4] = {
 {1,1,1,1},{1,1,1,1},{1,1,1,1},{1,1,1,1}
 };

 for(i=0; i<4; i++)
  {
   for(j=0; j<4; j++)
   {
    if(backup[i][j] != KeySta[i][j])
    {
     if(backup[i][j] == 0)
     {
      KeyAction(KeyCodeMap[i][j]);
     }
     backup[i][j] = KeySta[i][j];
    }
   } 
  }

 
}

/* 按键扫描函数，需在定时中断中调用，推荐调用间隔1ms */
void KeyScan()
{
    unsigned char i;
    static unsigned char keyout = 0;   //矩阵按键扫描输出索引
    static unsigned char keybuf[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}
    };

    //将一行的4个按键值移入缓冲区
    keybuf[keyout][0] = (keybuf[keyout][0] << 1) | KEY_IN_1;
    keybuf[keyout][1] = (keybuf[keyout][1] << 1) | KEY_IN_2;
    keybuf[keyout][2] = (keybuf[keyout][2] << 1) | KEY_IN_3;
    keybuf[keyout][3] = (keybuf[keyout][3] << 1) | KEY_IN_4;
    //消抖后更新按键状态
    for (i=0; i<4; i++)  //每行4个按键，所以循环4次
    {
        if ((keybuf[keyout][i] & 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[keyout][i] = 0;
        }
        else if ((keybuf[keyout][i] & 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[keyout][i] = 1;
        }
    }
    //执行下一次的扫描输出
    keyout++;                //输出索引递增
    keyout = keyout & 0x03;  //索引值加到4即归零
    switch (keyout)          //根据索引，释放当前输出引脚，拉低下次的输出引脚
    {
        case 0: KEY_OUT_4 = 1; KEY_OUT_1 = 0; break;
        case 1: KEY_OUT_1 = 1; KEY_OUT_2 = 0; break;
        case 2: KEY_OUT_2 = 1; KEY_OUT_3 = 0; break;
        case 3: KEY_OUT_3 = 1; KEY_OUT_4 = 0; break;
        default: break;
    }
}
/* 数码管动态扫描刷新函数，需在定时中断中调用 */
void LedScan()
{
    static unsigned char i = 0;  //动态扫描的索引
   
    P0 = 0xFF;   //显示消隐
    switch (i)
    {
        case 0: ADDR2=0; ADDR1=0; ADDR0=0; i++; P0=LedBuff[0]; break;
        case 1: ADDR2=0; ADDR1=0; ADDR0=1; i++; P0=LedBuff[1]; break;
        case 2: ADDR2=0; ADDR1=1; ADDR0=0; i++; P0=LedBuff[2]; break;
        case 3: ADDR2=0; ADDR1=1; ADDR0=1; i++; P0=LedBuff[3]; break;
        case 4: ADDR2=1; ADDR1=0; ADDR0=0; i++; P0=LedBuff[4]; break;
        case 5: ADDR2=1; ADDR1=0; ADDR0=1; i=0; P0=LedBuff[5]; break;
        default: break;
    }
}

/* T0中断服务函数，用于数码管显示扫描与按键扫描 */
void InterruptTimer0() interrupt 1
{
 TH0 = 0xFC;
 TL0 = 0x67;
 LedScan();
 KeyScan();
}