//#include"reg51.h"
 //*******************************ds18b20
unsigned char ds18b20_num1[8]={0x8e,0x00,0x00,0x00,0xb8,0xc5,0x30,0x28};
unsigned char ds18b20_num2[8]={0xb9,0X00,0X00,0x00,0xb8,0Xc5,0X31,0X28};
unsigned char ds18b20_num3[8]={0xe0,0x00,0x00,0x00,0xb8,0xc5,0x32,0x28};
sbit DQ =P3^6;   //定義通信端口

//延時(shí)函數(shù)

void delay(unsigned int i)
{
 while(i--);
}

//初始化函數(shù)
 unsigned char Init_DS18B20(void)
{
 unsigned char x=0;
 DQ = 1;    //DQ復(fù)位
 delay(8);  //稍做延時(shí)
 DQ = 0;    //單片機(jī)將DQ拉低
 delay(80); //精確延時(shí) 大于 480us
 DQ = 1;    //拉高總線
 delay(14);
 x=DQ;      //稍做延時(shí)后 如果x=0則初始化成功 x=1則初始化失敗
 delay(20);
 return (x);
}

//讀一個(gè)字節(jié)
ReadOneChar(void)
{
unsigned char i=0;
unsigned char dat = 0;
for (i=8;i>0;i--)
 {
  DQ = 0; // 給脈沖信號(hào)
  dat>>=1;
  DQ = 1; // 給脈沖信號(hào)
  if(DQ)
   dat|=0x80;
  delay(4);
 }
 return(dat);
}

//寫一個(gè)字節(jié)
WriteOneChar(unsigned char dat)
{
 unsigned char i=0;
 for (i=8; i>0; i--)
 {
  DQ = 0;
  DQ = dat&0x01;
  delay(5);
  DQ = 1;
  dat>>=1;
 }
//delay(4);
}
unsigned char * read_rom(void)
{
	unsigned char rom[8],i;
	Init_DS18B20();
	WriteOneChar(0x33);
	for(i=8;i>0;i--)
	{
		rom[i-1]=ReadOneChar();
	}
	return &rom[0];
}
bit match_rom(unsigned char *rom)
{
	unsigned char i;
	//Init_DS18B20();
	WriteOneChar(0x55);
	for(i=8;i>0;i--)
	{
		WriteOneChar(*(rom+i-1));
	//	rom++;
	}
	return 1;
}		

//讀取溫度
ReadTemperature(unsigned char n)
{
unsigned char a=0;
unsigned char b=0;
unsigned int t=0;
float tt=0;
Init_DS18B20();
WriteOneChar(0xCC); // 跳過讀序號(hào)列號(hào)的操作
WriteOneChar(0x44); // 啟動(dòng)溫度轉(zhuǎn)換
Init_DS18B20();
//WriteOneChar(0xCC); //跳過讀序號(hào)列號(hào)的操作
//if (n==1)  match_rom(ds18b20_num1);
//else if (n==2)  match_rom(ds18b20_num2);
//else if (n==3)  match_rom(ds18b20_num3);
//.......................
//else if (n==0) 
WriteOneChar(0xCC); //跳過讀序號(hào)列號(hào)的操作 
WriteOneChar(0xBE); //讀取溫度寄存器等（共可讀9個(gè)寄存器） 前兩個(gè)就是溫度
a=ReadOneChar();
b=ReadOneChar();
t=b;
t<<=8;
t=t|a;
tt=t*0.0625;
t= tt*10+0.5; //放大10倍輸出并四舍五入---此行沒用
return(t);
}
 //****************************************ds18b20結(jié)束
 unsigned char TempBuffer[5];
void IntToStr(unsigned int t, unsigned char *str, unsigned char n) 
{
	unsigned char a[5]; char i, j;    //取得整數(shù)值到數(shù)組                                 	
	a[0]=t/100;   //百位         	
	a[1]=(t/10)%10;//十位                                     	
	a[2]=t%10;    //個(gè)位                           	
	                                     	
                                                      
	for(i=0; i<3; i++)         //轉(zhuǎn)成ASCII碼              	
		a[i]=a[i]+'0';                                    	
	for(i=0; a[i]=='0' && i<=3; i++);                     	
	for(j=3-n; j<i; j++)       //填充空格                 	
		{ *str=' ';  str++; }                             	
	for(; i<3; i++)                                       	
		{ *str=a[i]; str++; }  //加入有效的數(shù)字           	
	*str='\0'; 
} 



/*
main()
{ 
//==讀取序列號(hào)操作。在1602上顯示。
 /*unsigned char i; 
unsigned char *ds1820rom;
  ds1820rom=read_rom();
  LCD_initial();
  LCD_set_position(0);
  for(i=0;i<8;i++)
  {unsigned char a;
   a=(*ds1820rom)/16;
  if(a>=0&&a<=9) a=a+'0';
  else if(a>=0x0a &&a<= 0x0f) a=a-10+'a';
  LCD_printc(a);
  a=(*ds1820rom)%16;
  if(a>=0&&a<=9) a=a+'0';
  else if(a>=0x0a &&a<= 0x0f) a=a-10+'a';
  LCD_printc(a);
  ds1820rom++;
  }
  while(1);*/

/*
unsigned int i,a;
    i=ReadTemperature(3); //讀溫度

    a=i;
    IntToStr(i,&TempBuffer[0],3);
    LCD_initial();
    LCD_set_position(0);
    LCD_prints("temperature :");
    LCD_set_position(0x40);
    LCD_printc(TempBuffer[0]); 
	LCD_printc(TempBuffer[1]);
	LCD_printc('.');
	LCD_printc(TempBuffer[2]);
	LCD_printc(' ');
	LCD_printc(0xDF);
	LCD_printc('C');
while(1)
 {	i=ReadTemperature(3); 
    if (i!=a )	  //如果有變化
	 {	 a=i;
  	IntToStr(i,&TempBuffer[0],3);
    LCD_initial();
    LCD_set_position(0);
    LCD_prints("temperature :");
    LCD_set_position(0x40);
    LCD_printc(TempBuffer[0]); 
	LCD_printc(TempBuffer[1]);
	LCD_printc('.');
	LCD_printc(TempBuffer[2]);
	LCD_printc(' ');
	LCD_printc(0xDF);
	LCD_printc('C');


	 }
} 	

}
  */