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数码管实现ds18b20显示

#include "reg52.h"
#include <intrins.h>
#define uint unsigned int 
#define uchar unsigned char 
sbit DQ = P3^7;  //从器件数据端
void delay(uchar x)
{
	while(x--);
}
const uchar table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
const uchar table1[]={0xbf,0x86,0xdb,0xcf,0xe6,0xed,0xfd,
                        0x87,0xff,0xef};
/*
delay(1)  	延时 7us
delay(7)  	延时63us
delay(100) 	延时 611us
*/

//单总线复位，启动，停止等
void IC_init()
{
	DQ = 0;
	delay(100);	  //主机拉低总线480us以上
	DQ = 1;	      //释放总线
	delay(100);	  //等待从器件拉低总线回复，延时大于480us
}

//读字节
uchar IC_read( )
{
	bit flag = 0;	
	
	uchar i = 0, temp = 0;
	
	for(i = 0; i < 8; i++)
	{	
		temp = temp >> 1;//注意此处移位
		DQ = 0;
		_nop_();		//拉低总线至少1us启动读
		DQ = 1;			//释放总线
		delay(1);		//延时，使从器件写数据
		flag = DQ;		//主机须在15us内读走数据
		if(flag == 1)
			temp = temp | 0x80;
		delay(7);		//建立一个读周期至少需60us的条件

		DQ = 1;			//释放总线，进入下一个写周期
		_nop_();		//两次读至少间隔1us
		_nop_();
	}

	return temp;
}

//写字节
void IC_write(uchar date)
{
	uchar temp = 0, i = 0;

	temp = date;

	for(i = 0; i < 8; i++)
	{
		DQ = 0;
		_nop_();		   //拉低总线，启动写
		DQ = temp & 0x01;  //在15us内需将数据写到总线
		delay(7);		   //建立大于45us的延时，完成一个写周期
		
		DQ = 1;		 	   //释放总线，进入下一个写周期
		_nop_();
		_nop_();
		temp = temp >> 1;
	}
}


void DS18B20_T(uchar *a1,uchar *a2,uchar *a3,uchar *a4,uchar *a5,uchar *a6,uint *t,uchar *fushu)
{
	uchar  tmp1 = 0, tmp0 = 0;
	
	IC_init();		 //启动
	
	IC_write(0xcc);  //跳过ROM

	IC_write(0x44);  //启动温度转换

	IC_init();		 //重新启动
	
	IC_write(0xcc);

	IC_write(0xbe);	  //读取温度

	tmp0=  IC_read(); //读低字节
	
	tmp1 = IC_read(); //读高字节
	if(tmp1>0xf8)
	{
		tmp1=~tmp1;
		tmp0=~tmp0+1;
		*fushu=1;
	}
	else
	*fushu=0;
	*t =(tmp1 * 256)|tmp0; 
	*t=(*t)*0.0625;
	*t= (*t)*100;  			
	*a1=*t/100000;
	*a2=(*t%100000)/10000;
	*a3=(*t%10000)/1000;
	*a4=(*t%1000)/100;
	*a5=(*t%100)/10;
	*a6=*t%10;
}
void xianshi(uchar *a,uchar *b,uchar *c,uchar *d,uchar *e,uchar *f,uchar *fushu)
{
	if(*fushu)
	{
		P2=0X7f;	
		P0=0x40;
		delay(100);
	}	
	else
	{
		P2=0X7f;	
		P0=table[*a];
		delay(100);
	}	
			
	P2=0Xbf;
	P0=table[*b];
	delay(100);	

	P2=0Xdf;
	P0=table[*c];
	delay(1000);	

	P2=0Xe7;
	P0=table1[*d];
	delay(1000);
	
	P2=0Xf7;
	P0=table[*e];
	delay(100);
	
	P2=0Xfb;	
	P0=table[*f];
	delay(100);		
}
void main()
{
	uchar a1,a2,a3,a4,a5,a6;
	uint t = 0;	 uchar fushu;
	while(1)
	{ 
	DS18B20_T(&a1,&a2,&a3,&a4,&a5,&a6,&t,&fushu);  
	xianshi(&a1,&a2,&a3,&a4,&a5,&a6,&fushu);
	}
}