51单片机系统中运用电脑上的大键盘.c

51单片机系统中运用电脑上的大键盘！ 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

/*=============================================================
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

AT89x51使用12M
                  Modified by Shen Peng!
                  Postgraduate of 2003, 7 Department
                  Harbin Engineering University
=============================================================*/
#include <at89x51.h>
#include "scancodes.h"
 

//#define Key_Data P3_4 //定义Keyboard引脚
//#define Key_CLK  P3_3


sbit Key_Data=P3^4;      //定义Keyboard引脚
sbit Key_CLK =P3^3;

sbit led1=P1^1;          // use the led to test the system 
sbit led2=P1^3;

 
   
//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);   //这是个键盘的译吗程序，并且显示出来，
void Init(void);                       //穿口的初始话‘
void sendtoPC(unsigned char);          //发送程序;

   

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
unsigned char command;                        //receive the command from PC


//static unsigned char BF = 1;                //标识是否有字符被收到

 void Init()

{
                // the oc is 12MHZ

  IE=0x98;      //1001 1000 //
  IP=0x10;      //ps is the first class;
  TMOD=0x21;    //0010 0001
  SCON=0x50;    // 0101 0000 
  PCON=0x00;    // 0000 0000  // set the SMOD  1
  TL1=0xcc;     // set the baud; 600     //串口600；
  TH1=0xcc;     // 204 should be set;
  TR1=1;        //1100 1100

  //TL1=0xfd;    // set the baud; 9600                         
  // TH1=0xfd;    // 253 should be set;
  // TR1=1;       //1110 0110
} 
 

void main(void)
{     
                                  
   	unsigned char TempCyc;

     Init();                          // init the serial port
     sendtoPC(Shifted[34][1]);        // test the system,and restet;

//	Delay400Ms(); //启动等待，等LCM讲入工作状态
//	Delay5Ms(); //延时片刻(可不要)
                                  
//	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
   	IT1 = 1; //设外部中断1跳变触发;

	EA = 1;
	EX1 = 1; //开中断

	do
		{
            led2=~led2;             // test weather the mcu is death;
			if (BF)
				Decode(KeyV);
			else
				EA = 1; //开中断
              /// EX1 = 1;
		}
	while(1);
}
           
  /*
    
//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
{
    // led2=~led2;
	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)
		{
          led1=~led1;
         // led2=~led2;
			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)
          //  EX1 = 0;
		}
}

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
                              // sendtoPC("");
								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]);
                                sendtoPC(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]);
                                sendtoPC(Shifted[TempCyc][1]);
							}

					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
}



void UART_ISR(void) interrupt 4      //serial interrupt 

{

    unsigned char ch ;
    ch = 0;
    if(RI)
       {
        RI = 0;
        ch = SBUF;	   	   /* 清除RS接收标志位*/
        command = ch;	        
        }

      if(TI) 
      {
      TI=0;            //send  this finished, can send another again ;
      }
}




void sendtoPC(unsigned char dat)
{

      if(TI) 
      TI = 0;			    	/* clear transmit interrupt flag*/
	  SBUF = dat;				/* start sending one byte*/
	  while (!TI);				/* wait until sent*/

}