SimpleNixieClock/inc/ds3231.h

#pragma once
#ifndef DS3231_H
#define DS3231_H

#include <avr/io.h>

/* i2c slave address of the DS3231 chip */
#define DS3231_I2C_WRADDR  0xD0
#define DS3231_I2C_RDADDR  0xD1

/* timekeeping registers */
#define DS3231_TIME_CAL_ADDR        0x00
#define DS3231_CALENDAR_ADDR        0x03
#define DS3231_ALARM1_ADDR          0x07
#define DS3231_ALARM2_ADDR          0x0B
#define DS3231_CONTROL_ADDR         0x0E
#define DS3231_STATUS_ADDR          0x0F
#define DS3231_AGING_OFFSET_ADDR    0x10
#define DS3231_TEMPERATURE_ADDR     0x11

// control register bits
#define DS3231_A1IE     0x01
#define DS3231_A2IE     0x02
#define DS3231_INTCN    0x04
#define DS3231_RS1	    0x08
#define DS3231_RS2	    0x10
#define DS3231_CONV	    0x20
#define DS3231_BBSQW	  0x40
#define DS3231_OSC_OSC	0x80

/* square-wave output frequency */
#define DS3231_1HZ	    0x00
#define DS3231_1024HZ	  DS3231_RS1
#define DS3231_4096HZ	  DS3231_RS2
#define DS3231_8192HZ	  (DS3231_RS1 | DS3231_RS2)

/* status register bits */
#define DS3231_A1F      0x01
#define DS3231_A2F      0x02
#define DS3231_OSF      0x80

/* RTC Status */
typedef enum {
  RTC_OK  = 0x00,
  RTC_TWI_TimeOut,
  RTC_TWI_Error
} rtc_status_t;

/**
 * @brief   Clock sructure.
 * @note    structure of ds3231 data.
 */
typedef struct {
  /**
   * @brief  Seconds
   */
  uint8_t Sec;
  /**
   * @brief  Minutes
   */
  uint8_t Min;
  /**
   * @brief  Hours
   */
  uint8_t Hr;
  /**
   * @brief  Week Day
   */
  uint8_t WD;
  /**
   * @brief  Day of Month
   */
  uint8_t Day;
  /**
   * @brief  Month
   */
  uint8_t Mon;
  /**
   * @brief  Year
   */
  uint8_t Year;
} rtc_t;

void RTC_Init(void);

void RTC_ReadAll(rtc_t * data);
void RTC_ReadTime(rtc_t * data);
void RTC_ReadCalendar(rtc_t * data);

void RTC_WriteAll(rtc_t * data);
void RTC_WriteTime(rtc_t * data);
void RTC_WriteHHMM(rtc_t * data);
void RTC_WriteCalendar(rtc_t * data);

uint8_t bcd2bin(uint8_t bcd);
uint8_t bin2bcd(uint8_t bin);

#endif // DS3231_H