AntiGuide: Ds18B20Light

#ifndef DS18B20_H
#define DS18B20_H
#include <Arduino.h>
class DS18B20 {
public:
void begin(int p);
int read();

private:
byte OneWireInByte();

void OneWireReset();
void OneWireOutByte(byte d) ;

 int pin;
 long idhigh;
 long idlow;	
};
#endif

#include "DS18B20.h"
#include <Arduino.h>

 void DS18B20::begin(int p){
  pin=p;
 }
 
 int DS18B20::read(){ 
 int HighByte, LowByte, TReading ;

  OneWireReset();
  OneWireOutByte(0xcc);
  OneWireOutByte( 0x44); // perform temperature conversion, strong pullup for one sec

  OneWireReset();
  OneWireOutByte(0xcc);
  OneWireOutByte( 0xbe);

  LowByte = OneWireInByte();
 
  HighByte = OneWireInByte();
 TReading = (HighByte << 8) + LowByte;
 return TReading;
 
 }

void DS18B20::OneWireReset() // reset.  Should improve to act as a presence pulse
{
     digitalWrite(pin, LOW);
     pinMode(pin, OUTPUT); // bring low for 500 us
     delayMicroseconds(500);
     pinMode(pin, INPUT_PULLUP);
     delayMicroseconds(500);
}

void DS18B20::OneWireOutByte(byte d) // output byte d (least sig bit first).
{
   byte n;

   for(n=8; n!=0; n--)
   {
      if ((d & 0x01) == 1)  // test least sig bit
      {
         digitalWrite(pin, LOW);
         pinMode(pin, OUTPUT);
         delayMicroseconds(5);
         pinMode(pin, INPUT_PULLUP);
         delayMicroseconds(60);
      }
      else
      {
         digitalWrite(pin, LOW);
         pinMode(pin, OUTPUT);
         delayMicroseconds(60);
         pinMode(pin, INPUT_PULLUP);
      }

      d=d>>1; // now the next bit is in the least sig bit position.
   }

}


byte DS18B20::OneWireInByte() // read byte, least sig byte first
{
    byte d, n, b;

    for (n=0; n<8; n++)
    {
        digitalWrite(pin, LOW);
        pinMode(pin, OUTPUT);
        delayMicroseconds(5);
        pinMode(pin, INPUT_PULLUP);
        delayMicroseconds(5);
        b = digitalRead(pin);
        delayMicroseconds(50);
        d = (d >> 1) | (b<<7); // shift d to right and insert b in most sig bit position
    }
    return(d);
}