/*============================================================
        使用1602液晶顯示和PS/2鍵盤的示例     明浩  2004/2
        -------------------------------------------------
           http://www.cdle.net  http://bbs.cdle.net
==============================================================

SMC1602A(16*2)模擬口線接線方式
連接線圖:	
       ---------------------------------------------------
       |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電阻到GND|
       ---------------------------------------------------

Keyboard接線
      PS/2--------51
      1 DATA------P3.4
      3 GND
      4 VCC
      5 CLK-------P3.3 接在51的外部中斷，觸發方式為低電平

本程序源碼只供學習參考，不得應用于商業用途，如有需要請聯系作者。

[注:AT89x51使用12M或11.0592M晶振,實測使用11.0592M]
[Keil uV2 7.01編譯運行通過 程序中沒有做鍵盤數據的奇偶校驗]

=============================================================*/
#include <at89x51.h>
#include "scancodes.h"

#define LCM_RW  P2_0 //定義LCD引腳
#define LCM_RS  P2_1
#define LCM_E   P2_2
#define LCM_Data  P1

#define Key_Data P3_4 //定義Keyboard引腳
#define Key_CLK  P3_3

#define Busy    0x80 //用于檢測LCM狀態字中的Busy標識

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; //中斷次數計數
static unsigned char KeyV; //鍵值
static unsigned char DisNum = 0; //顯示用指針
static unsigned char Key_UP=0, Shift = 0;//Key_UP是鍵松開標識，Shift是Shift鍵按下標識
static unsigned char BF = 0; //標識是否有字符被收到

void main(void)
{
	unsigned char TempCyc;

	Delay400Ms(); //啟動等待，等LCM講入工作狀態
	LCMInit(); //LCM初始化
	Delay5Ms(); //延時片刻(可不要)

	DisplayListChar(0, 0, cdle_net);
	DisplayListChar(0, 1, email);
	ReadDataLCM();//測試用句無意義
	for (TempCyc=0; TempCyc<10; TempCyc++)
			Delay400Ms(); //延時
	DisplayListChar(0, 1, Cls);	
	
	IT1 = 0; //設外部中斷1為低電平觸發
	EA = 1;
	EX1 = 1; //開中斷

	do
		{
			if (BF)
				Decode(KeyV);
			else
				EA = 1; //開中斷
		}
	while(1);
}

//寫數據
void WriteDataLCM(unsigned char WDLCM) 
{
	ReadStatusLCM(); //檢測忙
	LCM_Data = WDLCM;
	LCM_RS = 1;
	LCM_RW = 0;
	LCM_E = 0; //若晶振速度太高可以在這后加小的延時
	LCM_E = 0; //延時
	LCM_E = 1;
}

//寫指令
void WriteCommandLCM(unsigned char WCLCM,BuysC) //BuysC為0時忽略忙檢測
{
	if (BuysC) ReadStatusLCM(); //根據需要檢測忙
	LCM_Data = WCLCM;
	LCM_RS = 0;
	LCM_RW = 0;	
	LCM_E = 0;
	LCM_E = 0;
	LCM_E = 1;	
}

//讀數據
unsigned char ReadDataLCM(void)
{
	LCM_RS = 1; 
	LCM_RW = 1;
	LCM_E = 0;
	LCM_E = 0;
	LCM_E = 1;
	return(LCM_Data);
}

//讀狀態
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); //檢測忙信號
	return(LCM_Data);
}

void LCMInit(void) //LCM初始化
{
	LCM_Data = 0;
	WriteCommandLCM(0x38,0); //三次顯示模式設置，不檢測忙信號
	Delay5Ms(); 
	WriteCommandLCM(0x38,0);
	Delay5Ms(); 
	WriteCommandLCM(0x38,0);
	Delay5Ms(); 

	WriteCommandLCM(0x38,1); //顯示模式設置,開始要求每次檢測忙信號
	WriteCommandLCM(0x08,1); //關閉顯示
	WriteCommandLCM(0x01,1); //顯示清屏
	WriteCommandLCM(0x06,1); // 顯示光標移動設置
	WriteCommandLCM(0x0F,1); // 顯示開及光標設置
}

//按指定位置顯示一個字符
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; //當要顯示第二行時地址碼+0x40;
	X |= 0x80; //算出指令碼
	WriteCommandLCM(X, 1); //發命令字
	WriteDataLCM(DData); //發數據
}

//按指定位置顯示一串字符
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) //若到達字串尾則退出
		{
			if (X <= 0xF) //X坐標應小于0xF
				{
					DisplayOneChar(X, Y, DData[ListLength]); //顯示單個字符
					ListLength++;
					X++;
				}
		}
}

//5ms延時
void Delay5Ms(void)
{
	unsigned int TempCyc = 5552;
	while(TempCyc--);
}

//400ms延時
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; //因鍵盤數據是低>>高，結合上一句所以右移一位
			if (Key_Data) KeyV = KeyV | 0x80; //當鍵盤數據線為1時為1到最高位
		}
	IntNum++;
	while (!Key_CLK); //等待PS/2CLK拉高

	if (IntNum > 10)
		{
			IntNum = 0; //當中斷11次后表示一幀數據收完，清變量準備下一次接收
			BF = 1; //標識有字符輸入完了
			EA = 0; //關中斷等顯示完后再開中斷 (注：如這里不用BF和關中斷直接調Decode()則所Decode中所調用的所有函數要聲明為再入函數)
		}
}

void Decode(unsigned char ScanCode) //注意:如SHIFT+G為12H 34H F0H 34H F0H 12H，也就是說shift的通碼+G的通碼+shift的斷碼+G的斷碼
{
	unsigned char TempCyc;	

	if (!Key_UP)                //當鍵盤松開時
		{
			switch (ScanCode)
				{
					case 0xF0 :	// 當收到0xF0，Key_UP置1表示斷碼開始
						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沒按下
							{
								for (TempCyc = 0;(UnShifted[TempCyc][0]!=ScanCode)&&(TempCyc<59); TempCyc++); //查表顯示
								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++); //查表顯示
								if (Shifted[TempCyc][0] == ScanCode) DisplayOneChar(DisNum, 1, Shifted[TempCyc][1]);
								DisNum++;
							}

					break;
				}
		}
	else
		{	
			Key_UP = 0;
			switch (ScanCode) //當鍵松開時不處理判碼，如G 34H F0H 34H 那么第二個34H不會被處理
				{
					case 0x12 :	// 左 SHIFT
						Shift = 0;
					break;

					case 0x59 :	// 右 SHIFT
						Shift = 0;
					break;
				}
		}
	BF = 0; //標識字符處理完了
}