temp-control.c

基于51的18b20温度采集控制系统. 可以设置两个报警值.

#include <reg52.H>         
#define uint  unsigned int  
#define uchar unsigned char
uchar discod[16]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xc0,0x83,0xc6,0xa1,0x86,0x8e};
////////////////={  0   1    2     3   4    5     6   7    8    9    a     b    c   d     e   f};
uint disbuf[4]={0x01,0x02,0x03,0x04};  //led buffer
uint fled,alrmcode=600,coolcode=500;   //fled function led
uint temp;                             //temp register
/////////////////////////////////////////////////////
sbit led1=P0^0;                        //io define
sbit led2=P0^1;
sbit led3=P0^2;
sbit led4=P0^3;

sbit k1=P2^0;
sbit k2=P2^1;
sbit k3=P2^2;
sbit k4=P2^3;
sbit ALRM   =P2^4;
sbit ALRMLED=P2^5;
sbit COOL   =P2^6;
sbit COOLLED=P2^7;

sbit DQ=P3^7;   //18b20port
////////////////////////////////////////////////////
main()
{
for(;;)
 {
uchar d;
P0=0;
temp=ReadTemperature();fled=12;                              //read temp 
if(temp>alrmcode){ALRM=1;ALRMLED=1;}else{ALRM=0;ALRMLED=0;}  //alrm function
if(temp>coolcode){COOL=1;COOLLED=1;}else{COOL=0;COOLLED=0;}  //cool function
for(d=0;d<7;d++){display();}                                 //display
if(k4==0){key();}                                            //read key
 }
} 
/////////////////////////////////////////////////////
key()
{

  if(k4==0)                                         //recognize  button  enter
    { temp=alrmcode;fled=11;                        //display  alrmcode function
	while(k4==0){display();}                        //wait  enter relax
    while(k3==1)                                    //keep  key set in
         {         
		  
         if(k1==0){temp=alrmcode;fled=11;}          //if k1 press set alrmcode
         if(k2==0){temp=coolcode;fled=15;}          //if k2 press set coolcode
           display();               
         if(k4==0)                                  //wait enter code
	       {                                        //here use if(k4==0) for jump out the second key set
back:	   while(k3==0);                            
           if(k4==0)                                //recognize enter key on
	         {
              while(k3==1)                          //keep  key set in
	               {
	              display();
			            if(fled==11)                //set the code of alrm
			              {      
			                while(k3==1)
			                {
					        if(k1==0){alrmcode++;temp=alrmcode;}
						    if(k2==0){alrmcode--;temp=alrmcode;}
							display();display();display();display();display();display();
							display();display();display();display();display();display();
				            }
			              }
			            if(fled==15)                //set the code of cool
			              {
			                while(k3==1)
			                {
						    if(k1==0){coolcode++;temp=coolcode;}
					    	if(k2==0){coolcode--;temp=coolcode;}
							display();display();display();display();display();display();
							display();display();display();display();display();display();
				            }
					       }
						   goto back;               //jump out the deep key set procedure
			}
         } 
		}  			  
}    }  }      
/////////////////////////////////////////////////////
display()
{
uchar c;
disbuf[0]=temp/100;                        //hundred  
disbuf[1]=(temp%100)/10;                   //ten
disbuf[2]=((temp%100)%10);                 //the unit
disbuf[3]=fled;                            //function led
P1=discod[disbuf[0]];P0=1;
for(c=0;c<150;c++);
P1=(discod[disbuf[1]]&0x7f);P0=2;          //here use dot
for(c=0;c<150;c++);
P1=discod[disbuf[2]];P0=4;
for(c=0;c<150;c++);
P1=discod[disbuf[3]];P0=8;
for(c=0;c<150;c++);
}
//延时函数

void delay(unsigned int i)
{
 while(i--);
}

//初始化函数
Init_DS18B20(void)
{
 unsigned char x=0;
 DQ = 1;    //DQ复位
 delay(8);  //稍做延时
 DQ = 0;    //单片机将DQ拉低
 delay(80); //精确延时 大于 480us
 DQ = 1;    //拉高总线
 delay(14);
 x=DQ;      //稍做延时后 如果x=0则初始化成功 x=1则初始化失败
 delay(20);
}

//读一个字节
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;
  delay(4);
 }
 return(dat);
}

//写一个字节
WriteOneChar(unsigned char dat)
{
 unsigned char i=0;
 for (i=8; i>0; i--)
 {
  DQ = 0;
  DQ = dat&0x01;
  delay(5);
  DQ = 1;
  dat>>=1;
 }
//delay(4);
}

//读取温度
ReadTemperature(void)
{
unsigned char a=0;
unsigned char b=0;
unsigned int t=0;
float tt=0;
Init_DS18B20();
WriteOneChar(0xCC); // 跳过读序号列号的操作
WriteOneChar(0x44); // 启动温度转换
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();
b=ReadOneChar();
t=b;
t<<=8;
t=t|a;
tt=t*0.625;
//t= tt*10+0.5; //放大10倍输出并四舍五入---此行没用
return(tt);
}