wordclock/libraries/DS3231/DS3231.h

#ifndef DS3231_h
#define DS3231_h

#include <Arduino.h>

/**
  TODO: alarms
 */
class DS3231
{
public:
  // begin function
  void begin();
  // get seconds
  uint8_t getSeconds();
  // set seconds
  void setSeconds(uint8_t seconds);
  // increment seconds
  void incrementSeconds();
  // decrement seconds
  void decrementSeconds();
  // get minutes
  uint8_t getMinutes();
  // set minutes
  void setMinutes(uint8_t minutes);
  // increment minutes
  void incrementMinutes();
  // decrement minutes
  void decrementMinutes();
  // get hours
  uint8_t getHours();
  // set hours
  void setHours(uint8_t hours);
  // increment hours
  void incrementHours();
  // decrement hours
  void decrementHours();
  // get day
  uint8_t getDay();
  // set day
  void setDay(uint8_t day);
  // get date
  uint8_t getDate();
  // set date
  void setDate(uint8_t date);
  // increment date
  void incrementDate();
  // decrement date
  void decrementDate();
  // get month
  uint8_t getMonth();
  // set month
  void setMonth(uint8_t month);
  // increment month
  void incrementMonth();
  // decrement month
  void decrementMonth();
  // get year
  int16_t getYear();
  // set year
  void setYear(int16_t year);
  // increment year
  void incrementYear();
  // decrement year
  void decrementYear();
  // get control register
  uint8_t getControlRegister();
  // set control register
  void setControlRegister(uint8_t value);
  // set status register
  uint8_t getStatusRegister();
  // set status register
  void setStatusRegister(uint8_t value);
  // get temperature
  uint8_t getTemperature();
  // helpers
protected:
  // get register
  uint8_t getRegister(uint8_t address);
  // set register
  void setRegister(uint8_t address, uint8_t value);
  // decimal to binary coded decimal
  uint8_t dectobcd(uint8_t value);
  // binary coded decimal to decimal
  uint8_t bcdtodec(uint8_t value);
  // get century value
  uint8_t getCentury();
  // set century value
  void setCentury(uint8_t century);
};

// I2C address
#define DS3231_I2C_ADDRESS 0x68

// I2C registers
#define DS3231_SECONDS 0x00
#define DS3231_MINUTES 0x01
#define DS3231_HOURS 0x02
#define DS3231_DAY 0x03
#define DS3231_DATE 0x04
#define DS3231_MONTH 0x05
#define DS3231_YEAR 0x06
#define DS3231_ALARM1_SECONDS 0x07
#define DS3231_ALARM1_MINUTES 0x08
#define DS3231_ALARM1_HOURS 0x09
#define DS3231_ALARM1_DATE 0x0A
#define DS3231_ALARM2_MINUTES 0x0B
#define DS3231_ALARM2_HOURS 0x0C
#define DS3231_ALARM1_DATE 0x0D
#define DS3231_CONTROL 0x0E
#define DS3231_STATUS 0x0F
#define DS3231_AGING_OFFSET 0x10
#define DS3231_MSB_TEMP 0x11
#define DS3231_LSB_TEMP 0x12

// control registers
#define DS3231_CONTROL_A1IE 0x01
#define DS3231_CONTROL_A2IE 0x02
#define DS3231_CONTROL_INTCN 0x04
#define DS3231_CONTROL_RS1 0x08
#define DS3231_CONTROL_RS2 0x10
#define DS3231_CONTROL_CONV 0x20
#define DS3231_CONTROL_BBSQW 0x40
#define DS3231_CONTROL_EOSC 0x80

// status registers
#define DS3231_STATUSL_A1F 0x01
#define DS3231_STATUSL_A2F 0x02
#define DS3231_STATUSL_BSY 0x04
#define DS3231_STATUSL_EN32KHZ 0x08
#define DS3231_STATUSL_OSF 0x80

#endif