单片机实验3提示

键盘与LCD实验

对4×4矩阵式键盘电路的键值进行编码，编程实现在LCD液晶显示器上显示每个按键的ASCII码。

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(⊙﹏⊙)呃这个和去年一样

单片机实验说明＜四＞矩阵键盘与LCD基本使用

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#include "8052.h"

#define uchar unsigned char
#define uint unsigned int

#define lcden P1_2
#define lcdrs P1_0
#define rw P1_1

/* IO引脚分配定义 */
#define KEY_IN_1  P2_4  //矩阵按键的扫描输入引脚1
#define KEY_IN_2  P2_5  //矩阵按键的扫描输入引脚2
#define KEY_IN_3  P2_6  //矩阵按键的扫描输入引脚3
#define KEY_IN_4  P2_7  //矩阵按键的扫描输入引脚4
#define KEY_OUT_1 P2_0  //矩阵按键的扫描输出引脚1
#define KEY_OUT_2 P2_1  //矩阵按键的扫描输出引脚2
#define KEY_OUT_3 P2_2  //矩阵按键的扫描输出引脚3
#define KEY_OUT_4 P2_3  //矩阵按键的扫描输出引脚4

#define LSA P1_5  //LED位选译码地址引脚A
#define LSB P1_6  //LED位选译码地址引脚B
#define LSC P1_7  //LED位选译码地址引脚C

unsigned char disBuf=0;
uchar table1[] = "Welcome To CSLG!";
uchar table2[] = "0123456789ABCDEF";
uchar table3[] = "                ";
uchar num;

const unsigned char KeyCodeMap[4][4] = {  //矩阵按键到标准键码的映射表
    { '0',  '1',  '2', '3' },  //
    { '4',  '5',  '6', '7' },  //
    { '8',  '9',  'a', 'b' },  //
    { 'c',  'd',  'e', 'f' }   //
};

unsigned char KeySta[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} };

/* 函数声明 */
void KeyScan();
void KeyDriver();
void KeyAction(unsigned char keycode);

/* 按键驱动函数，检测按键动作，调度相应动作函数，需在主循环中调用 */
void KeyDriver()
{
    unsigned char i, j;
    static unsigned char backup[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}
    };

    for (i=0; i<4; i++)  //循环检测4*4的矩阵按键
    {
        for (j=0; j<4; j++)
        {
            if (backup[i][j] != KeySta[i][j])    //检测按键动作
            {
                if (backup[i][j] != 0)           //按键按下时执行动作
                {
                    KeyAction(KeyCodeMap[i][j]); //调用按键动作函数
                }
                backup[i][j] = KeySta[i][j];     //刷新前一次的备份值
            }
        }
    }
}
/* 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 &= 0x03;  //索引值加到4即归零
    switch (keyout)  //根据索引值，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;
    }
}

void KeyAction(unsigned char keycode)
{   
    disBuf = keycode;   
}

void delay(uint z) {
    uint x, y;
    for(x = z; x > 0; x--)
        for(y = 110; y > 0; y--);
}

void write_com(uchar com) {
    lcdrs = 0;
    P0 = com;
    delay(5);
    lcden = 1;
    delay(5);
    lcden = 0;
}

void write_data(uchar date) {
    lcdrs = 1;
    P0 = date;
    delay(5);
    lcden = 1;
    delay(5);
    lcden = 0;
}

void init() {   
    rw = 0;
    lcden = 0;
    write_com(0x38);
    write_com(0x0e);
    write_com(0x06);
    write_com(0x01);
}

void main() {
    init();
    write_com( 0x00 | 0x80 );
    for(num = 0; num < 16; num++) {
        write_data(table1[num]);
        delay(100);
    }
    write_com( 0x40 | 0x80 );
    for(num = 0; num < 16; num++) {
        write_data(table2[num]);
        delay(100);
    }
    write_com( 0x40 | 0x80 );
    for(num = 0; num < 16; num++) {
        write_data(table3[num]);
        delay(100);
    }    
    while(1)
    {
        KeyScan();
        KeyDriver();
        write_com( 0x40 | 0x80 );
        write_data(disBuf);
    }

}

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