/*
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-------P3.4    |
       |DB1-----P1.1 |	DB5-----P1.5 |	RS-------P3.3    |
       |DB2-----P1.2 |	DB6-----P1.6 |	E--------P3.5    |
       |DB3-----P1.3 |	DB7-----P1.7 |	VLCD接1K電阻到GND|
       ---------------------------------------------------
接線：模塊TRIG接 P3.7  ECH0 接P3.6

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:stc89c52使用12M或11.0592M晶振,實測使用11.0592M]
=============================================================*/
#include <AT89x51.H>		//器件配置文件
#include <intrins.h>
#define  RX  P3_6
#define  TX  P3_7

#define LCM_RW  P2_3 //定義LCD引腳
#define LCM_RS  P2_4
#define LCM_E   P2_2
#define LCM_Data  P1

#define Key_Data P3_3 //定義Keyboard引腳
#define Key_CLK  P3_2

#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 mcustudio[] ={"==Range Finder=="};
unsigned char code email[] =    {"heyaodz@163.com "};
unsigned char code Cls[] =      {"                "};
unsigned char code ASCII[15] =    {'0','1','2','3','4','5','6','7','8','9','.','-','M'};

static unsigned char DisNum = 0; //顯示用指針				  
       unsigned int  time=0;
	   unsigned long S=0;
	   bit      flag =0;
	   unsigned char disbuff[4]	   ={ 0,0,0,0,};


//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 Conut(void)
	{
	 time=TH0*256+TL0;
	 TH0=0;
	 TL0=0;
	
	 S=(time*1.8)/10;     //算出來是MM
	 if((S>=7000)||flag==1) //超出測量范圍顯示“-”
	 {	 
	  flag=0;
	 
	  DisplayOneChar(0, 1, ASCII[11]);
	  DisplayOneChar(1, 1, ASCII[10]);	//顯示點
	  DisplayOneChar(2, 1, ASCII[11]);
	  DisplayOneChar(3, 1, ASCII[11]);
	  DisplayOneChar(4, 1, ASCII[11]);
	  DisplayOneChar(5, 1, ASCII[12]);	//顯示M
	 }
	 else
	 {
	  disbuff[0]=S/1000;
	  disbuff[1]=S/100%10;
	  disbuff[2]=S/10%10;
	  disbuff[3]=S%10;
	  DisplayOneChar(0, 1, ASCII[disbuff[0]]);
	  DisplayOneChar(1, 1, ASCII[10]);	//顯示點
	  DisplayOneChar(2, 1, ASCII[disbuff[1]]);
	  DisplayOneChar(3, 1, ASCII[disbuff[2]]);
	  DisplayOneChar(4, 1, ASCII[disbuff[3]]);
	  DisplayOneChar(5, 1, ASCII[12]);	//顯示M
	 }
	}
/********************************************************/
     void zd0() interrupt 1 		 //T0中斷用來計數器溢出,超過測距范圍
  {
    flag=1;							 //中斷溢出標志
	RX=0;
  }
/********************************************************/
     void  StartModule() 		         //啟動模塊
  {
	  TX=1;			                     //啟動一次模塊
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_();
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_();
	  TX=0;
  }
void Timer_Count(void)
{
		 TR0=1;			    //開啟計數
	     while(RX);			//當RX為1計數并等待
	     TR0=0;				//關閉計數
         Conut();			//計算

}

/********************************************************/ 
void delayms(unsigned int ms)
{
	unsigned char i=100,j;
	for(;ms;ms--)
	{
		while(--i)
		{
			j=10;
			while(--j);
		}
	}
}
/*********************************************************/
void main(void)
{
    unsigned int valA;
	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, mcustudio);
	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);	
	 TMOD=0x01;		   //設T0為方式1，GATE=1；
	 TH0=0;
	 TL0=0;          
	 ET0=1;             //允許T0中斷
	 EA=1;			   //開啟總中斷			
	
 	while(1)
	  {
		
		delayms(60);
		RX=1;
	    StartModule();
        for(valA=7510;valA>0;valA--)
	    {
		   
	       if(RX==1)
		   {
           Timer_Count();
		   }
    	 }
	  }
}