18b20.h

基于51的lcd1602数字时钟 可调解时间 自动调节星期

#include <reg52.h>
#include <intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit DS=P2^2;
sbit diola=P2^5;            //define interface
void delay1(uchar count)
{
    while(count>0) count--;
}

void dsreset(void)       //send reset and initialization command
{
  DS=0;
  delay1(100);
  DS=1;
  delay1(204);
}

bit tmpreadbit(void)       //read a bit
{
   bit temp;
    DS=0;
    _nop_();
    DS=1;
    _nop_();
    temp=DS;
    delay1(8);
    return temp; 
}

uchar tmpread(void)   //read a byte date
{
     uchar i,byte=0;
     bit j;
     for(i=0;i<8;i++)
     {
         byte=_cror_(byte,1);
         j=tmpreadbit();
         if(j==0) byte=byte|0x00;
         else   byte=byte|0x80;
     }
     return byte;
}

void tmpwritebyte(uchar command)   //write a byte to ds18b20
{
   uchar i;
  for(i=0;i<8;i++) 
    { 
      if((command & 0x01)==0) 
        { 
          DS=0; 
          delay1(8); 
          DS=1;
          _nop_();
        } 
       else 
          { 
            DS=0; 
            _nop_();
            DS=1; 
            delay1(8);
          } 
      command=_cror_(command,1);      
    } 
}

void tmpchange(void)  //DS18B20 begin change
{
  dsreset();
  tmpwritebyte(0xcc);  // address all drivers on bus
  tmpwritebyte(0x44);  //  initiates a single temperature conversion
}

uint tmp()               //get the temperature
{
  float tt;
  uchar a,b;
  uint temp;             // variable of temperature
  dsreset();
  tmpwritebyte(0xcc);
  tmpwritebyte(0xbe);
  a=tmpread();
  b=tmpread();
  temp=b;
  temp<<=8;             //two byte  compose a int variable
  temp=temp|a;
  tt=temp*0.0625;
  temp=tt*10+0.5;
  return temp;
}