DS3231.h

/*
 * MIT License
 * Copyright (c) 2021 Brian T. Park
 */
 
#ifndef ACE_TIME_HW_DS3231_MODULE_H
#define ACE_TIME_HW_DS3231_MODULE_H
 
#include <stdint.h>
#include <AceCommon.h> // bcdToDec(), decToBcd()
#include "HardwareDateTime.h"
#include "HardwareTemperature.h"
 
namespace ace_time {
namespace hw {
 
class HardwareDateTime;
class HardwareTemperature;
 
template <typename T_WIREI>
class DS3231 {
  private:
    static const uint8_t kAddress = 0x68;
 
  public:
    explicit DS3231(const T_WIREI& wireInterface) :
        mWireInterface(wireInterface)
    {}
 
    void readDateTime(HardwareDateTime* dateTime) const {
      using ace_common::bcdToDec;
 
      mWireInterface.beginTransmission(kAddress);
      mWireInterface.write(0); // set DS3231 register pointer to 00h
      mWireInterface.endTransmission();
 
      // request seven bytes from DS3231 starting from register 00h
      mWireInterface.requestFrom(kAddress, (uint8_t) 7);
      dateTime->second = bcdToDec(mWireInterface.read() & 0x7F);
      dateTime->minute = bcdToDec(mWireInterface.read());
      dateTime->hour = bcdToDec(mWireInterface.read() & 0x3F);
      dateTime->dayOfWeek = bcdToDec(mWireInterface.read());
      dateTime->day = bcdToDec(mWireInterface.read());
      dateTime->month = bcdToDec(mWireInterface.read());
      dateTime->year = bcdToDec(mWireInterface.read());
    }
 
    void setDateTime(const HardwareDateTime& dateTime) const {
      using ace_common::decToBcd;
 
      mWireInterface.beginTransmission(kAddress);
      mWireInterface.write(0); // set next input to start at 'seconds' register
      mWireInterface.write(decToBcd(dateTime.second));
      mWireInterface.write(decToBcd(dateTime.minute));
      mWireInterface.write(decToBcd(dateTime.hour));
      mWireInterface.write(decToBcd(dateTime.dayOfWeek));
      mWireInterface.write(decToBcd(dateTime.day));
      mWireInterface.write(decToBcd(dateTime.month));
      mWireInterface.write(decToBcd(dateTime.year));
      mWireInterface.endTransmission();
    }
 
    void readTemperature(HardwareTemperature* temperature) const {
      mWireInterface.beginTransmission(kAddress);
      mWireInterface.write(0x11); // set DS3231 register pointer to 11h
      mWireInterface.endTransmission();
 
      mWireInterface.requestFrom(kAddress, (uint8_t) 2);
      temperature->msb = mWireInterface.read();
      temperature->lsb = mWireInterface.read();
    }
 
  private:
    const T_WIREI mWireInterface;
};
 
} // hw
} // ace_time
 
#endif