基于DS18B20的52单片机的温度计设计

基于单片机的DS18B20温度计设计
//Main.c 主程序
#include <reg52.h>
#include <18b20.h>
#define DataPort P0 //定义数据端口程序中遇到DataPort 则用P0 替换
sbit LATCH1=P1^0;//定义锁存使能端口段锁存
sbit LATCH2=P1^1;// 位锁存
bit ReadTempFlag;//定义读时间标志
unsigned char code DuanMa[10]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};// 显示段码值0~9 共阴数码管dp-a
unsigned char code WeiMa[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};//分别对应相应的数码管点亮,即位码
unsigned char TempData[4]; //存储显示值的全局变量
void Display(unsigned char FirstBit,unsigned char Num);//数码管显示函数
void Init_Timer0(void);//定时器初始化
void main (void)
{
unsigned int TempH,TempL,temp;
Init_Timer0();//定时器初始化
while (1) //主循环
{
if(ReadTempFlag==1)
{
ReadTempFlag=0;
temp=ReadTemperature();//读取温度函数
if(temp&0x8000)
{
TempData[0]=0x40;//负号标志
temp=~temp; // 取反加1
temp +=1;
TempH=temp>>4;
TempL=temp&0x0F;
TempL=TempL*6.25/10;//小数近似处理
if(TempH/10==0)
TempData[1]=0; //十位温度
else
TempData[1]=DuanMa[TempH/10];
TempData[2]=DuanMa[TempH%10]|0x80; //个位温度,带小数点
TempData[3]=DuanMa[TempL];
}
else
{
TempH=temp>>4;
TempL=temp&0x0F;
TempL=TempL*6.25/10;//小数近似处理
if(TempH/100==0)
TempData[0]=0;
else
TempData[0]=DuanMa[TempH/100]; //百位温度
if((TempH/100==0)&&((TempH%100)/10==0))//消隐
TempData[1]=0;
else
TempData[1]=DuanMa[(TempH%100)/10]; //十位温度
TempData[2]=DuanMa[(TempH%100)%10]|0x80; //个位温度,带小数点TempData[3]=DuanMa[TempL];
}
}
}
}
void Display(unsigned char FirstBit,unsigned char Num)
{
static unsigned char i=0;
DataPort=0; //清空数据
LATCH1=1; //段锁存
LATCH1=0;
DataPort=WeiMa[i+FirstBit]; //取位码
LATCH2=1; //位锁存
LATCH2=0;
DataPort=TempData[i]; //取显示数据，段码
LATCH1=1; //段锁存
LATCH1=0;
i++;
if(i==Num)
i=0;
}
void Init_Timer0(void)//定时器初始化
{
TMOD |= 0x01;//使用模式1，16位定时器
EA=1; //总中断打开
ET0=1; //定时器中断打开
TR0=1; //定时器开关打开
}
void Timer0_isr(void) interrupt 1 //定时器中断程序
{
static unsigned int num;
TH0=(65536-2000)/256;//重新赋值2ms
TL0=(65536-2000)%256;
Display(0,4); // 调用数码管扫描num++;
if(num==300) //
{
num=0;
ReadTempFlag=1; //读标志位置1
}
}
//reg52.h
#ifndef __REG52_H__
#define __REG52_H__
sfr P0 = 0x80;
sfr P1 = 0x90;
sfr P2 = 0xA0;
sfr P3 = 0xB0;
sfr PSW = 0xD0;
sfr ACC = 0xE0;
sfr B = 0xF0;
sfr SP = 0x81;
sfr DPL = 0x82;
sfr DPH = 0x83;
sfr PCON = 0x87;
sfr TCON = 0x88;
sfr TMOD = 0x89;
sfr TL0 = 0x8A;
sfr TL1 = 0x8B;
sfr TH0 = 0x8C;
sfr TH1 = 0x8D;
sfr IE = 0xA8;
sfr IP = 0xB8;
sfr SCON = 0x98;
sfr SBUF = 0x99;
/* 8052 Extensions */
sfr T2CON = 0xC8;
sfr RCAP2L = 0xCA;
sfr RCAP2H = 0xCB;
sfr TL2 = 0xCC;
sfr TH2 = 0xCD;
/* BIT Registers */
/* PSW */
sbit CY = PSW^7;
sbit AC = PSW^6;
sbit F0 = PSW^5;
sbit RS1 = PSW^4;
sbit RS0 = PSW^3;
sbit OV = PSW^2;
sbit P = PSW^0; //8052 sbit TF1 = TCON^7;
sbit TR1 = TCON^6;
sbit TF0 = TCON^5;
sbit TR0 = TCON^4;
sbit IE1 = TCON^3;
sbit IT1 = TCON^2;
sbit IE0 = TCON^1;
sbit IT0 = TCON^0;
sbit EA = IE^7;
sbit ET2 = IE^5; //8052 sbit ES = IE^4;
sbit ET1 = IE^3;
sbit EX1 = IE^2;
sbit ET0 = IE^1;
sbit EX0 = IE^0;
/* IP */
sbit PT2 = IP^5;
sbit PS = IP^4;
sbit PT1 = IP^3;
sbit PX1 = IP^2;
sbit PT0 = IP^1;
sbit PX0 = IP^0;
sbit RD = P3^7;
sbit WR = P3^6;
sbit T1 = P3^5;
sbit T0 = P3^4;
sbit INT1 = P3^3;
sbit INT0 = P3^2;
sbit TXD = P3^1;
sbit RXD = P3^0;
sbit SM0 = SCON^7;
sbit SM1 = SCON^6;
sbit SM2 = SCON^5;
sbit REN = SCON^4;
sbit TB8 = SCON^3;
sbit RB8 = SCON^2;
sbit TI = SCON^1;
sbit RI = SCON^0;
sbit T2EX = P1^1; // 8052
sbit T2 = P1^0; // 8052
sbit TF2 = T2CON^7;
sbit EXF2 = T2CON^6;
sbit RCLK = T2CON^5;
sbit TCLK = T2CON^4;
sbit EXEN2 = T2CON^3;
sbit TR2 = T2CON^2;
sbit C_T2 = T2CON^1;
sbit CP_RL2 = T2CON^0;
#endif
//18b20.h
#ifndef __DS18B20_H__
#define __DS18B20_H__
#include <reg52.h>
#define uchar unsigned char
#define uint unsigned int;
/*端口定义*/
sbit DQ=P1^3;//ds18b20 端口
/*函数声明*/
unsigned int ReadTemperature(void); bit Init_DS18B20(void);
unsigned char ReadOneChar(void); void WriteOneChar(unsigned char dat); #endif
//delay.c
#ifndef __DELAY_H__
#define __DELAY_H__
/*微秒延时函数*/
void DelayUs2x(unsigned char t);
/*毫秒延时函数*/
void DelayMs(unsigned char t);
#endif
//18b20.c
#include <delay.h>
#include <18b20.h>
/*18b20初始化*/
bit Init_DS18B20(void)
{
bit dat=0;
DQ = 1; //DQ复位
DelayUs2x(5); //稍做延时
DQ = 0; //单片机将DQ拉低
DelayUs2x(200); //精确延时大于480us 小于960us
DelayUs2x(200);
DQ = 1; //拉高总线
DelayUs2x(50); //15~60us 后接收60-240us的存在脉冲
dat=DQ; //如果dat=0则初始化成功, dat=1则初始化失败DelayUs2x(25); //稍作延时返回
return dat;
}
/*读取一个字节*/
unsigned char ReadOneChar(void)
{
unsigned char i=0;
unsigned char dat = 0;
for (i=8;i>0;i--)
{
DQ = 0; // 给脉冲信号
dat>>=1;
DQ = 1; // 给脉冲信号
if(DQ)
dat|=0x80;
DelayUs2x(25);
}
return(dat);
}
/*写一个字节*/
void WriteOneChar(unsigned char dat)
{
unsigned char i=0;
for (i=8; i>0; i--)
{
DQ = 0;
DQ = dat&0x01;
DelayUs2x(25);
DQ = 1;
dat>>=1;
}
DelayUs2x(25);
}
/*读取温度函数*/
unsigned int ReadTemperature(void)
{
unsigned char a=0;
unsigned int b=0;
unsigned int t=0;
Init_DS18B20();//DS18B20初始化
WriteOneChar(0xCC); // 跳过读序号列号的操作
WriteOneChar(0x44); // 启动温度转换
DelayMs(10);// 延时10毫秒
Init_DS18B20();
WriteOneChar(0xCC); //跳过读序号列号的操作
WriteOneChar(0xBE); //读取温度寄存器等（共可读9个寄存器）前两个就是温度a=ReadOneChar(); //低位
b=ReadOneChar(); //高位
b<<=8;
t=a+b;
return(t);
}。