#include <AT89X52.H> 
 #include <INTRINS.h>
 unsigned char code Tab[]={0xff,0Xfd,0xff,0xfe,0xff,0xf7,0xff,0xfb,0xff,0xdf,0xff,0xef,0xff,0x7f,0xff,0xbf,
                           0Xfd,0xff,0xfe,0xff,0xf7,0xff,0xfb,0xff,0xdf,0xff,0xef,0xff,0x7f,0xff,0xbf,0xff};
 unsigned char code codedisplay[]={0xFF,0xFF,0xFF,0xE7,0xDB,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xBD,0xDB,0xE7,0xFF,0xFF,/*"0",0*/
                                   0xFF,0xFF,0xFF,0xEF,0x8F,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0x83,0xFF,0xFF,/*"1",1*/
                                   0xFF,0xFF,0xFF,0xC3,0xBD,0xBD,0xBD,0xFB,0xFB,0xF7,0xEF,0xDF,0xBD,0x81,0xFF,0xFF,/*"2",2*/
								   0xFF,0xFF,0xFF,0xC3,0xBD,0xBD,0xFB,0xE7,0xFB,0xFD,0xFD,0xBD,0xBB,0xC7,0xFF,0xFF,/*"3",3*/
                                   0xFF,0xFF,0xFF,0xFB,0xF3,0xEB,0xDB,0xDB,0xBB,0xBB,0x81,0xFB,0xFB,0xE1,0xFF,0xFF,/*"4",4*/
                                   0xFF,0xFF,0xFF,0x81,0xBF,0xBF,0xBF,0xA7,0x9B,0xFD,0xFD,0xBD,0xBB,0xC7,0xFF,0xFF,/*"5",5*/
								   0xFF,0xFF,0xFF,0xE3,0xDB,0xBF,0xBF,0xA7,0x9B,0xBD,0xBD,0xBD,0xDB,0xE7,0xFF,0xFF,/*"6",6*/
								   0xFF,0xFF,0xFF,0x81,0xBB,0xBB,0xF7,0xF7,0xEF,0xEF,0xEF,0xEF,0xEF,0xEF,0xFF,0xFF,/*"7",7*/
								   0xFF,0xFF,0xFF,0xC3,0xBD,0xBD,0xBD,0xDB,0xE7,0xDB,0xBD,0xBD,0xBD,0xC3,0xFF,0xFF,/*"8",8*/
								   0xFF,0xFF,0xFF,0xE7,0xDB,0xBD,0xBD,0xBD,0xD9,0xE5,0xFD,0xFD,0xDB,0xC7,0xFF,0xFF};/*"9",9*/



 unsigned char m; 
 unsigned int result,count=0;
 void delay(void)
{  unsigned char 	i,j;
   for(i=0;i<15;i++){	for(j=0;j<50;j++) ;	}
} 

unsigned char displaycount,x; 
unsigned char displaybuf[8]={0,0,0,0,0,0,0,0}; 
unsigned char timecount; 
unsigned char readdata[8]; 
 unsigned long a,aa,bb;
sbit DQ=P2^6;   //選P3.7口與DS18B20的數(shù)字信號(hào)輸出端DQ相連 
bit sflag; 
 
bit resetpulse(void)     //DS18B20初始化實(shí)現(xiàn)對DS18B20的復(fù)位
{ unsigned char pre;
  unsigned char i; 
  DQ=0;        //發(fā)出復(fù)位脈沖，將數(shù)據(jù)線下拉480μS－960μS 
  for(i=220;i>0;i--);  //（改！！！！！！！！！！！！！！！！！！！！）
  DQ=1;         //DS18B20等待15μS－60μS 
  for(i=60;i>0;i--); 
  pre=DQ; 
  for(i=150;i>0;i--);
  return(pre);    // DS18B20返回60μS－240μS存在低脈沖，判斷是否準(zhǔn)備好接受或發(fā)送數(shù)據(jù) 
}
 
void writecommandtods18b20(unsigned char command)    //寫時(shí)序 
{ 
  unsigned char i; 
  unsigned char j; 
   
  for(i=0;i<8;i++) 
    { 
      if((command & 0x01)==0)   //寫0時(shí)序 
        { 
          DQ=0;        //拉低單總線至少60μS，保證DS18B20在15μS－45μS時(shí)可以正確地采樣I/O總線上的低電平
          for(j=35;j>0;j--); 
          DQ=1; 
        } 
        else       //寫1時(shí)序
          { 
DQ=0;         //拉低單總線后，在15us之內(nèi)就得釋放
            for(j=2;j>0;j--); 
            DQ=1; 
            for(j=33;j>0;j--); 
          } 
      command=_cror_(command,1);       
    } 
} 
 
unsigned char readdatafromds18b20(void)     //讀時(shí)序   
{ 
  unsigned char i; 
  unsigned char j; 
  unsigned char temp; 
 
  temp=0; 
  for(i=0;i<8;i++) 
    { 
      temp=_cror_(temp,1);    
      DQ=0;                 //單總線拉低后，讀時(shí)序開始 
      _nop_(); 
      _nop_(); 
      DQ=1;                  //停止將數(shù)據(jù)線拉低，以讀取數(shù)據(jù)     
      for(j=10;j>0;j--); 
      if(DQ==1) 
        { 
          temp=temp | 0x80; 
        } 
        else 
          { 
            temp=temp | 0x00; 
          } 
      for(j=20;j>0;j--);  ////////////////////（改！！！！！！！！！！！！）
    } 
  return(temp); 
} 
 


void main(void)
  {	SCON=0; P1=0;
    //while(resetpulse());      //寫前調(diào)用初始化程序?qū)S18B20復(fù)位
    //writecommandtods18b20(0xcc);  //單片DS18B20工作，跳過讀ROM中64位地址的過程 
    //writecommandtods18b20(0x44); //啟動(dòng)DS18B20進(jìn)行溫度轉(zhuǎn)化，將結(jié)果存入內(nèi)部RAM中
   while(1)	   
    {         	
				  for(m=0;m<16;m++)
				   {   SBUF=codedisplay[displaybuf[0]*16+m];    while(!TI) ; TI=0;
		               SBUF=codedisplay[displaybuf[1]*16+m];    while(!TI) ; TI=0; 
			           SBUF=codedisplay[displaybuf[2]*16+m];   while(!TI) ; TI=0; 
			           SBUF=codedisplay[displaybuf[3]*16+m];    while(!TI) ; TI=0;
					   SBUF=codedisplay[displaybuf[4]*16+m];   while(!TI) ; TI=0; 
			           SBUF=codedisplay[displaybuf[5]*16+m];    while(!TI) ; TI=0; 
					   SBUF=codedisplay[displaybuf[6]*16+m];    while(!TI) ; TI=0; 
			           SBUF=codedisplay[displaybuf[7]*16+m];    while(!TI) ; TI=0;  
				       //P2_0=0;P2_1=0;P2_1=1;P2_1=0;P2_0=1;
					   SBUF=Tab[2*m]; while(!TI) ; TI=0;
					   SBUF=Tab[2*m+1];while(!TI) ; TI=0; 
				   	   
					   P3_4=0;P3_4=1;	P3_4=0;
	                   delay();
					   count++;
	  if(count==600)
	  {	count=0;
	  while(resetpulse());    //寫前調(diào)用初始化程序?qū)S18B20復(fù)位
      writecommandtods18b20(0xcc);      //單片DS18B20工作，跳過讀ROM中64位地址的過程 
      writecommandtods18b20(0xbe);      // 讀DS18B20RAM中溫度數(shù)據(jù)
      readdata[0]=readdatafromds18b20();   //溫度數(shù)據(jù)低8位賦值
      readdata[1]=readdatafromds18b20();    //溫度數(shù)據(jù)高8位賦值 
      sflag=0; 
      if((readdata[1] & 0xf8)!=0x00)   //溫度數(shù)據(jù)高5位為1時(shí)，溫度為負(fù)值 
        { 
          sflag=1; 
          readdata[1]=~readdata[1];   //對負(fù)溫度值進(jìn)行取反加1操作
          readdata[0]=~readdata[0]; 
          result=readdata[0]+1; 
          readdata[0]=result; 
          if(result>255) 
            { 
              readdata[1]++; 
            } 
        } 
      readdata[1]=readdata[1]&0x07;      //將代表符號(hào)的高5位數(shù)屏蔽
			aa=625;bb=(readdata[1]*256+readdata[0]);
		    a=bb*aa;   //計(jì)算實(shí)際溫度值
	
			
		    
		    displaybuf[0]=a/100000;      //給各顯示位賦溫度值
		    displaybuf[1]=a%100000/10000;
		    displaybuf[2]=a%10000/1000;
			displaybuf[3]=a%1000/100;
			displaybuf[4]=a%100/10;
			displaybuf[5]=a%10;
      while(resetpulse()); 
      writecommandtods18b20(0xcc); 
      writecommandtods18b20(0x44); 
      }
	   }}}