OneWireTempFast.h

#ifndef OneWireTempFast_h
#define OneWireTempFast_h

#include <inttypes.h>
#include <OneWire.h>

// Model IDs
#define DS18S20MODEL 0x10
#define DS18B20MODEL 0x28
#define DS1822MODEL  0x22
#define MAX31850MODEL 0x3B

// OneWire commands
#define STARTCONVO      0x44  // Tells device to take a temperature reading and put it on the scratchpad
#define COPYSCRATCH     0x48  // Copy EEPROM
#define READSCRATCH     0xBE  // Read EEPROM
#define WRITESCRATCH    0x4E  // Write to EEPROM
#define RECALLSCRATCH   0xB8  // Reload from last known
#define READPOWERSUPPLY 0xB4  // Determine if device needs parasite power
#define ALARMSEARCH     0xEC  // Query bus for devices with an alarm condition

// Scratchpad locations
#define TEMP_LSB        0
#define TEMP_MSB        1
#define HIGH_ALARM_TEMP 2
#define LOW_ALARM_TEMP  3
#define CONFIGURATION   4
#define INTERNAL_BYTE   5
#define COUNT_REMAIN    6
#define COUNT_PER_C     7
#define SCRATCHPAD_CRC  8

// Device resolution
#define TEMP_9_BIT  0x1F //  9 bit
#define TEMP_10_BIT 0x3F // 10 bit
#define TEMP_11_BIT 0x5F // 11 bit
#define TEMP_12_BIT 0x7F // 12 bit

// Error Codes
#define DEVICE_DISCONNECTED -127

typedef uint8_t DeviceAddress[8];

struct DST_Sensor {
  unsigned long timestamp;
  unsigned short temperature_Cx100;
  DeviceAddress address;
  uint8_t ScratchPad[9];
}


class OneWireTempFast
{
  public:

  OneWireTempFast(OneWire*);

  // initalise bus
  void begin(void);

  private:
  
  // parasite power on or off
  bool parasite;

  // used to determine the delay amount needed to allow for the
  // temperature conversion to take place
  uint8_t bitResolution;
  
  // used to requestTemperature with or without delay
  bool waitForConversion;
  
  // used to requestTemperature to dynamically check if a conversion is complete
  bool checkForConversion;
  
  // count of devices on the bus
  uint8_t devices;
  
  // Take a pointer to one wire instance
  OneWire* _wire;

  // reads scratchpad and returns the temperature in degrees C
  float calculateTemperature(uint8_t*, uint8_t*);
  
  void	blockTillConversionComplete(uint8_t*,uint8_t*);
  
  // required for alarmSearch 
  uint8_t alarmSearchAddress[8];
  char alarmSearchJunction;
  uint8_t alarmSearchExhausted;

  // the alarm handler function pointer
  AlarmHandler *_AlarmHandler;
  
};
#endif