#include "head_file.h"

sbit dq = P2^7;

void sdelay(unsigned int i)//延迟函数
{
		while(i--);
}
void DS18B20_Reset()//初始化
{
		unsigned char x=0;
		dq=1;   
		sdelay(8);  
		dq=0;   
		sdelay(80); 
		dq=1;   
		sdelay(14);
		sdelay(20);
}


void DS18B20_Write_Byte(unsigned char dat)
{
		unsigned char i=0;
		for(i=8;i>0;i--)
		{
				dq=0;
				dq=dat&0x01;
				sdelay(5);
				dq=1;
				dat>>=1;
		}
}
unsigned char DS18B20_Read_Byte()
{
	  unsigned char i=0,dat=0;
		for(i=8;i>0;i--)
		{
				dq=0;
				dat>>=1;
				dq=1;
				if(dq)
				dat|=0x80;
				sdelay(8);
		}
		return(dat);
}

unsigned int GET_Temperature() //获得当前温度
{
		unsigned char a=0,b=0;
		unsigned int t=0;
		float tt=0;
		EA = 0;
		DS18B20_Reset();
		DS18B20_Write_Byte(0xCC);//跳过ROM
		DS18B20_Write_Byte(0x44);//开启温度转换
		sdelay(5);
		DS18B20_Reset();
		DS18B20_Write_Byte(0xCC); 
		DS18B20_Write_Byte(0xBE);//读暂存器
		a=DS18B20_Read_Byte();
		b=DS18B20_Read_Byte();
	  EA = 1;
		t = b<<8;
		t+=a;
		t=t*0.625;
		t=t%1000;
		t/=10;
		return(t);
}