DS18B20.hh

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#ifndef COSA_DS18B20_HH
#define COSA_DS18B20_HH

#include <OWI.h>

#include "Cosa/Types.h"
#include "Cosa/IOStream.hh"

class DS18B20 : public OWI::Driver {
public:
  class Search : public OWI::Search {
  public:
    Search(OWI* owi) : OWI::Search(owi, FAMILY_CODE) {}

    DS18B20* next();
  };

  DS18B20(OWI* pin, const char* name = NULL) :
    OWI::Driver(pin, name),
    m_parasite(0),
    m_start(0L),
    m_converting(false)
  {}

  DS18B20(OWI* pin, const uint8_t* rom, const char* name = NULL) :
    OWI::Driver(pin, rom, name),
    m_parasite(0),
    m_start(0L),
    m_converting(false)
  {}

  bool connect(uint8_t index);

  void resolution(uint8_t bits);

  void set_trigger(int8_t low, int8_t high)
    __attribute__((always_inline))
  {
    m_scratchpad.low_trigger = low;
    m_scratchpad.high_trigger = high;
  }

  int16_t temperature() const
    __attribute__((always_inline))
  {
    return (m_scratchpad.temperature);
  }

  uint8_t resolution() const
    __attribute__((always_inline))
  {
    if (m_rom[0] == 0) return (0);
    return (9 + (m_scratchpad.configuration >> 5));
  }

  void get_trigger(int8_t& low, int8_t& high) const
    __attribute__((always_inline))
  {
    low = m_scratchpad.low_trigger;
    high = m_scratchpad.high_trigger;
  }

  bool convert_request();

  static bool convert_request(OWI* owi,
                              uint8_t resolution = 12,
                              bool parasite = false);

  bool write_scratchpad();

  bool read_scratchpad(bool flag = true);

  bool copy_scratchpad();

  bool recall();

  bool read_power_supply();

  static void print(IOStream& outs, int16_t temp);

protected:
  enum {
    FAMILY_CODE = 0x28,
    CONVERT_T = 0x44,
    READ_SCRATCHPAD = 0xBE,
    WRITE_SCRATCHPAD = 0x4E,
    COPY_SCRATCHPAD = 0x48,
    RECALL_E = 0xB8,
    READ_POWER_SUPPLY = 0xB4
  } __attribute__((packed));

  struct scratchpad_t {
    int16_t temperature;        
    int8_t high_trigger;        
    int8_t low_trigger;         
    uint8_t configuration;      
    uint8_t reserved[3];        
    uint8_t crc;                
  };
  scratchpad_t m_scratchpad;

  static const uint8_t CONFIG_MAX = 3;

  uint8_t m_parasite;

  uint32_t m_start;

  uint8_t m_converting;

  static const uint16_t MAX_CONVERSION_TIME = 750;

  static const uint16_t MIN_COPY_PULLUP = 10;

  void power_off()
    __attribute__((always_inline))
  {
    if (m_parasite) m_pin->power_off();
  }

  friend IOStream& operator<<(IOStream& outs, DS18B20& thermometer);
};

IOStream& operator<<(IOStream& outs, DS18B20& thermometer);

#endif