Si70XX.hh

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#ifndef COSA_Si70XX_HH
#define COSA_Si70XX_HH

#include "Cosa/TWI.hh"
#include <math.h>

class Si70XX : private TWI::Driver {
public:
  Si70XX() : TWI::Driver(0x40) {}

  bool read_user_register(uint8_t &reg)
  {
    return (read(READ_RHT_USER_REG_1, reg));
  }

  bool read_electronic_serial_number(uint8_t snr[8]);

  bool read_firmware_revision(uint8_t &rev);

  bool measure_humidity()
  {
    return (issue(MEASURE_RH_NO_HOLD));
  }

  float read_humidity()
  {
    uint16_t value;
    if (!read(value)) (NAN);
    return (((125.00 * value) / 65536) - 6.00);
  }

  float read_humidity_temperature()
  {
    uint16_t value;
    if (!issue(READ_RH_TEMP)) return (NAN);
    if (!read(value, false)) return (NAN);
    return (((175.72 * value) / 65536) - 46.85);
  }

  bool measure_temperature()
  {
    return (issue(MEASURE_TEMP_NO_HOLD));
  }

  float read_temperature()
  {
    uint16_t value;
    if (!read(value)) return (NAN);
    return (((175.72 * value) / 65536) - 46.85);
  }

protected:
  enum Command {
    MEASURE_RH_HOLD = 0xE5,      
    MEASURE_RH_NO_HOLD = 0xF5,   
    MEASURE_TEMP_HOLD = 0xE3,    
    MEASURE_TEMP_NO_HOLD = 0xF3, 
    READ_RH_TEMP = 0xE0,         
    RESET = 0xFE,                
    WRITE_RHT_USER_REG_1 = 0xE6, 
    READ_RHT_USER_REG_1 = 0xE7,  
    READ_ID_1 = 0xFA0F,          
    READ_ID_2 = 0xFCC8,          
    READ_REV = 0x84B8            
  } __attribute__((packed));

  bool issue(uint8_t cmd);

  bool read(uint16_t& value, bool check = true);

  bool read(uint8_t cmd, uint8_t& value);
};

#endif