ps2key.c
/*============================================================
使用1602液晶显示和PS/2键盘的示例 明浩 2004/2
-------------------------------------------------
http://www.cdle.net http://bbs.cdle.net
==============================================================

SMC1602A(16*2)模拟口线接线方式
连接线图:
---------------------------------------------------
|LCM-----51 | LCM-----51 | LCM------51 |
--------------------------------------------------|
|DB0-----P1.0 | DB4-----P1.4 | RW-------P2.0 |
|DB1-----P1.1 | DB5-----P1.5 | RS-------P2.1 |
|DB2-----P1.2 | DB6-----P1.6 | E--------P2.2 |
|DB3-----P1.3 | DB7-----P1.7 | VLCD接1K电阻到GND|
---------------------------------------------------

Keyboard接线
PS/2--------51
1 DATA------P3.4
3 GND
4 VCC
5 CLK-------P3.3 接在51的外部中断，触发方式为低电平

本程序源码只供学习参考，不得应用于商业用途，如有需要请联系作者。

[注:AT89x51使用12M或11.0592M晶振,实测使用11.0592M]
[Keil uV2 7.01编译运行通过 程序中没有做键盘数据的奇偶校验]

=============================================================*/
#include <at89x51.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11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
}

scancodes.h

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',
};