单片机温控 c 程序

#include <reg51.h>
sbit DQ = P3^3;     //定义DS18B20端口DQ  
sbit BEEP=P3^4 ;
unsigned char presence ;
unsigned char code  LEDData[ ]   = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,
                                                          0x7F,0x6F,0x00};
unsigned char data  temp_data[2] = {0x00,0x00};
unsigned char data  display[5] =  {0x00,0x00,0x00,0x00,0x00};
unsigned char code  ditab[16] =   {0x00,0x01,0x01,0x02,0x03,0x03,0x04,0x04,
                                                       0x05,0x06,0x06,0x07,0x08,0x08,0x09,0x09};
void beep(); 
sbit DIN = P2^7;   //小数点
bit  flash=0;          //显示开关标记
/**********************************************************/
void Delay(unsigned int num)//延时函数
{
  while( --num );
}
/**********************************************************/
 Init_DS18B20(void)//初始化ds1820
{
  
     DQ = 1;      //DQ复位
     Delay(8);    //稍做延时
     DQ = 0;      //单片机将DQ拉低
     Delay(90);   //精确延时 大于 480us
     DQ = 1;       //拉高总线
     Delay(8);
     presence = DQ;    //如果=0则初始化成功 =1则初始化失败
     Delay(100);