ds3231.h File Reference

Chip data for Maxim DS3231 I2C RTC/TCXO/Crystal. More...

#include <bsp430/core.h>
#include <time.h>

Go to the source code of this file.

Data Structures
struct	sDS3231registers

Macros
#define	DS3231_I2C_ADDRESS   0x68

Typedefs
typedef struct sDS3231registers	sDS3231registers

Functions
uint8_t	ucDS3231encodeHour (unsigned int hours, int is_12h)
unsigned int	uiDS3231decodeHour (uint8_t hour_ds3231)
const struct tm *	xDS3231registersToTm (const sDS3231registers *regp, struct tm *timep)
const sDS3231registers *	xDS3231tmToRegisters (const struct tm *timep, sDS3231registers *regp)

Detailed Description

Chip data for Maxim DS3231 I2C RTC/TCXO/Crystal.

This file contains the register map for the DS3231 real-time clock chip. There is no abstraction for the functional capability of the chip, except that there are routines to convert between the register map and POSIX standard time structures.

To incorporate the conversion routines add the following to your Makefile:

VPATH += $(BSP430_ROOT)/chips
MODULES += chips/ds3231

Homepage

http://github.com/pabigot/bsp430

Copyright

Copyright 2013-2014, Peter A. Bigot. Licensed under BSD-3-Clause

Macro Definition Documentation

#define DS3231_I2C_ADDRESS   0x68

I2C address for DS3231 I2C RTX/TCXO/Crystal

Typedef Documentation

typedef struct sDS3231registers sDS3231registers

DS3231 register map

Function Documentation

uint8_t ucDS3231encodeHour	(	unsigned int	hours,
		int	is_12h
	)

Convert from integer hour value to DS3231 encoded hour

The DS3231 represents hours as a register encoding either a 12-hr or 24-hr time, not a basic BCD representation.

Parameters

hours	the integer hour value in the range 0..23
is_12h	non-zero to represent the time as 12h with AM/PM; zero to represent time as a 24-hour value.

Returns

hour value encoded in DS3231 format

unsigned int uiDS3231decodeHour

(

uint8_t

hour_ds3231

)

Convert from encoded DS3231 hour value to integer hour

Parameters

hour_ds3231

Hour value encoded in DS3231 including 12h/24h flag in BIT6

Returns

integer hour value in range 0..23

const struct tm* xDS3231registersToTm	(	const sDS3231registers *	regp,
		struct tm *	timep
	)

Convert DS3231 date/time register settings to POSIX standard structure.

The previous contents of *timep are completely erased. The time conversion supports both 12-hour and 24-hour formats.

Parameters

regp	pointer to a DS3231 register map complete through byte 0x06.
timep	pointer to a POSIX time structure that will be cleared and initialized to the time recorded in regp

Returns

timep

const sDS3231registers* xDS3231tmToRegisters	(	const struct tm *	timep,
		sDS3231registers *	regp
	)

Convert POSIX time structure to DSD3231 date/time register settings.

The first seven bytes of *regp are erased, except that BIT6 of sDS3231registers::hours is preserved to record whether 12-hour or 24-hour time is desired. The remaining bytes of *regp are unmodified.

Parameters

timep	pointer to the POSIX time
regp	pointer to a DS3231 register map

Returns

regp