#include "reg51.h"
#include "scancodes.h"
#define LCM_RW P2_0//定义LCD引脚
#define LCM_RS P2_1
#define LCM_E P2_2
#define LCM_Data P1
#define Key_Data P3_4//定义Keyboard引脚
#define Key_CLK P3_3
#define Busy 0x80//用于检测LCM状态字中的Busy标识
void LCMInit(void);
void DisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData);
void DisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData);
void Delay5Ms(void);
void Delay400Ms(void);
void Decode(unsigned char ScanCode);
void WriteDataLCM(unsigned char WDLCM);
void WriteCommandLCM(unsigned char WCLCM, BuysC);
unsigned char ReadDataLCM(void);
unsigned char ReadStatusLCM(void);
unsigned char code cdle_net[] = {"www.cdle.net--"};
unsigned char code email[] = {"pnzwzw@cdle.net"};
unsigned char code Cls[] = {" "};
static unsigned char IntNum = 0;//中断次数计数
static unsigned char KeyV;//键值
static unsigned char DisNum = 0;//显示用指针
static unsigned char Key_UP = 0, Shift = 0; //Key_UP是键松开标识，Shift是Shift键按下标识
static unsigned char BF = 0;//标识是否有字符被收到
void main(void)
{
    unsigned char TempCyc;

    Delay400Ms();//启动等待，等LCM讲入工作状态
    LCMInit();//LCM初始化
    Delay5Ms();//延时片刻(可不要)

    DisplayListChar(0, 0, cdle_net);
    DisplayListChar(0, 1, email);
    ReadDataLCM();//测试用句无意义
    for (TempCyc = 0; TempCyc < 10; TempCyc++) {
        Delay400Ms();    //延时
    }
    DisplayListChar(0, 1, Cls);

    IT1 = 0;//设外部中断1为低电平触发
    EA = 1;
    EX1 = 1;//开中断

    do {
        if (BF) {
            Decode(KeyV);
        }
        else {
            EA = 1;    //开中断
        }
    }
    while (1);
}
//写数据
void WriteDataLCM(unsigned char WDLCM)
{
    ReadStatusLCM();//检测忙
    LCM_Data = WDLCM;
    LCM_RS = 1;
    LCM_RW = 0;
    LCM_E = 0;//若晶振速度太高可以在这后加小的延时
    LCM_E = 0;//延时
    LCM_E = 1;
}
//写指令
void WriteCommandLCM(unsigned char WCLCM, BuysC) //BuysC为0时忽略忙检测
{
    if (BuysC) {
        ReadStatusLCM();    //根据需要检测忙
    }
    LCM_Data = WCLCM;
    LCM_RS = 0;
    LCM_RW = 0;
    LCM_E = 0;
    LCM_E = 0;
    LCM_E = 1;
}
//读数据
unsigned char ReadDataLCM(void)
{
    LCM_RS = 1;
    LCM_RW = 1;
    LCM_E = 0;
    LCM_E = 0;
    LCM_E = 1;
    return (LCM_Data);
}
//读状态
unsigned char ReadStatusLCM(void)
{
    LCM_Data = 0xFF;
    LCM_RS = 0;
    LCM_RW = 1;
    LCM_E = 0;
    LCM_E = 0;
    LCM_E = 1;
    while (LCM_Data & Busy);//检测忙信号
    return (LCM_Data);
}
void LCMInit(void)//LCM初始化
{
    LCM_Data = 0;
    WriteCommandLCM(0x38, 0); //三次显示模式设置，不检测忙信号
    Delay5Ms();
    WriteCommandLCM(0x38, 0);
    Delay5Ms();
    WriteCommandLCM(0x38, 0);
    Delay5Ms();

    WriteCommandLCM(0x38, 1); //显示模式设置,开始要求每次检测忙信号
    WriteCommandLCM(0x08, 1); //关闭显示
    WriteCommandLCM(0x01, 1); //显示清屏
    WriteCommandLCM(0x06, 1); // 显示光标移动设置
    WriteCommandLCM(0x0F, 1); // 显示开及光标设置
}
//按指定位置显示一个字符
void DisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData)
{
    Y &= 0x1;
    X &= 0xF;//限制X不能大于15，Y不能大于1
    if (Y) {
        X |= 0x40;    //当要显示第二行时地址码+0x40;
    }
    X |= 0x80;//算出指令码
    WriteCommandLCM(X, 1);//发命令字
    WriteDataLCM(DData);//发数据
}
//按指定位置显示一串字符
void DisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData)
{
    unsigned char ListLength;

    ListLength = 0;
    Y &= 0x1;
    X &= 0xF;//限制X不能大于15，Y不能大于1
    while (DData[ListLength] > 0x19) { //若到达字串尾则退出
        if (X <= 0xF) { //X坐标应小于0xF
            DisplayOneChar(X, Y, DData[ListLength]);//显示单个字符
            ListLength++;
            X++;
        }
    }
}
//5ms延时
void Delay5Ms(void)
{
    unsigned int TempCyc = 5552;
    while (TempCyc--);
}
//400ms延时
void Delay400Ms(void)
{
    unsigned char TempCycA = 5;
    unsigned int TempCycB;
    while (TempCycA--) {
        TempCycB = 7269;
        while (TempCycB--);
    };
}
void Keyboard_out(void) interrupt 2
{
    if ((IntNum > 0) && (IntNum < 9)) {
        KeyV = KeyV >> 1;//因键盘数据是低>>高，结合上一句所以右移一位
        if (Key_Data) {
            KeyV = KeyV | 0x80;    //当键盘数据线为1时为1到最高位
        }
    }
    IntNum++;
    while (!Key_CLK);//等待PS/2CLK拉高

    if (IntNum > 10) {
        IntNum = 0;//当中断10次后表示一帧数据收完，清变量准备下一次接收
        BF = 1;//标识有字符输入完了
        EA = 0;//关中断等显示完后再开中断 (注：如这里不用BF和关中断直接调Decode()则所Decode中所调用的所有函数要声明为再入函数)
    }
}
void Decode(unsigned char ScanCode)//注意:如SHIFT+G为12H 34H F0H 34H F0H 12H，也就是说shift的通码+G的通码+shift的断码+G的断码
{
    unsigned char TempCyc;

    if (!Key_UP) { //当键盘松开时
        switch (ScanCode) {
        case 0xF0 :// 当收到0xF0，Key_UP置1表示断码开始
            Key_UP = 1;
            break;

        case 0x12 :// 左 SHIFT
            Shift = 1;
            break;

        case 0x59 :// 右 SHIFT
            Shift = 1;
            break;

        default:
            if (DisNum > 15) {
                DisplayListChar(0, 1, Cls);//清LCD第二行
                DisNum = 0;
            }
            if (!Shift) { //如果SHIFT没按下
                for (TempCyc = 0; (UnShifted[TempCyc][0] != ScanCode) && (TempCyc < 59); TempCyc++); //查表显示
                if (UnShifted[TempCyc][0] == ScanCode) {
                    DisplayOneChar(DisNum, 1, UnShifted[TempCyc][1]);
                }
                DisNum++;
            }
            else { //按下SHIFT
                for (TempCyc = 0; (Shifted[TempCyc][0] != ScanCode) && (TempCyc < 59); TempCyc++); //查表显示
                if (Shifted[TempCyc][0] == ScanCode) {
                    DisplayOneChar(DisNum, 1, Shifted[TempCyc][1]);
                }
                DisNum++;
            }

            break;
        }
    }
    else {
        Key_UP = 0;
        switch (ScanCode) { //当键松开时不处理判码，如G 34H F0H 34H 那么第二个34H不会被处理
        case 0x12 :// 左 SHIFT
            Shift = 0;
            break;

        case 0x59 :// 右 SHIFT
            Shift = 0;
            break;
        }
    }
    BF = 0;//标识字符处理完了
}
以下为 scancodes.h 文件
unsigned char code UnShifted[59][2] = {
    0x1C, 'a',
    0x32, 'b',
    0x21, 'c',
    0x23, 'd',
    0x24, 'e',
    0x2B, 'f',
    0x34, 'g',
    0x33, 'h',
    0x43, 'i',
    0x3B, 'j',
    0x42, 'k',
    0x4B, 'l',
    0x3A, 'm',
    0x31, 'n',
    0x44, 'o',
    0x4D, 'p',
    0x15, 'q',
    0x2D, 'r',
    0x1B, 's',
    0x2C, 't',
    0x3C, 'u',
    0x2A, 'v',
    0x1D, 'w',
    0x22, 'x',
    0x35, 'y',
    0x1A, 'z',
    0x45, '0',
    0x16, '1',
    0x1E, '2',
    0x26, '3',
    0x25, '4',
    0x2E, '5',
    0x36, '6',
    0x3D, '7',
    0x3E, '8',
    0x46, '9',
    0x0E, '`',
    0x4E, '-',
    0x55, '=',
    0x5D, '\\',
    0x29, ' ',
    0x54, '[',
    0x5B, ']',
    0x4C, ';',
    0x52, '\'',
    0x41, ',',
    0x49, '.',
    0x4A, '/',
    0x71, '.',
    0x70, '0',
    0x69, '1',
    0x72, '2',
    0x7A, '3',
    0x6B, '4',
    0x73, '5',
    0x74, '6',
    0x6C, '7',
    0x75, '8',
    0x7D, '9',
};
unsigned char code Shifted[59][2] = {
    0x1C, 'A',
    0x32, 'B',
    0x21, 'C',
    0x23, 'D',
    0x24, 'E',
    0x2B, 'F',
    0x34, 'G',
    0x33, 'H',
    0x43, 'I',
    0x3B, 'J',
    0x42, 'K',
    0x4B, 'L',
    0x3A, 'M',
    0x31, 'N',
    0x44, 'O',
    0x4D, 'P',
    0x15, 'Q',
    0x2D, 'R',
    0x1B, 'S',
    0x2C, 'T',
    0x3C, 'U',
    0x2A, 'V',
    0x1D, 'W',
    0x22, 'X',
    0x35, 'Y',
    0x1A, 'Z',
    0x45, '0',
    0x16, '1',
    0x1E, '2',
    0x26, '3',
    0x25, '4',
    0x2E, '5',
    0x36, '6',
    0x3D, '7',
    0x3E, '8',
    0x46, '9',
    0x0E, '~',
    0x4E, '_',
    0x55, '+',
    0x5D, '|',
    0x29, ' ',
    0x54, '{',
    0x5B, '}',
    0x4C, ':',
    0x52, '"',
    0x41, '<',
    0x49, '>',
    0x4A, '?',
    0x71, '.',
    0x70, '0',
    0x69, '1',
    0x72, '2',
    0x7A, '3',
    0x6B, '4',
    0x73, '5',
    0x74, '6',
    0x6C, '7',
    0x75, '8',
    0x7D, '9',
};