Communicates with a DS3231 realtime clock chip via I2C. More...

#include <DS3231RTC.h>

Inheritance diagram for DS3231RTC:

Public Member Functions
	DS3231RTC (I2CMaster &bus, uint8_t oneHzPin=255)
	Attaches to a realtime clock slave device on bus. More...

bool	isRealTime () const
	Returns true if the realtime clock is on the I2C bus; false if the time and date are simulated.

bool	hasUpdates ()
	Returns true if there are updates.

void	readTime (RTCTime *value)
	Reads the current time from the realtime clock into value. More...

void	readDate (RTCDate *value)
	Reads the current date from the realtime clock into value. More...

void	writeTime (const RTCTime *value)
	Updates the time in the realtime clock to match value. More...

void	writeDate (const RTCDate *value)
	Updates the date in the realtime clock to match value. More...

void	readAlarm (uint8_t alarmNum, RTCAlarm *value)
	Reads the details of the alarm with index alarmNum into value. More...

void	writeAlarm (uint8_t alarmNum, const RTCAlarm *value)
	Updates the details of the alarm with index alarmNum from value. More...

bool	setAlarm (uint8_t alarmNum, const RTCAlarm *value)
	Sets the alarm with index alarmNum from value. More...

int	readTemperature ()
	Reads the value of the temperature sensor and returns the temperature in quarters of a degree celcius. More...

void	enableAlarmInterrupts ()
	Enables the generation of interrupts for alarms 0 and 1. More...

void	disableAlarmInterrupts ()
	Disables the generation of interrupts for alarms 0 and 1. More...

int	firedAlarm ()
	Determines which of alarms 0 or 1 have fired since the last call. More...

void	enable32kHzOutput ()
	Enables the 32 kHz output on the DS3231 chip. More...

void	disable32kHzOutput ()
	Disables the 32 kHz output on the DS3231 chip. More...

void	enableAlarm (uint8_t alarmNum)
	Enables a specific alarm. More...

void	disableAlarm (uint8_t alarmNum)
	Disables a specific alarm. More...

Public Member Functions inherited from RTC
	RTC ()
	Constructs a new realtime clock handler. More...

virtual int	byteCount () const
	Returns the number of bytes of non-volatile memory that can be used for storage of arbitrary settings, excluding storage used by alarms. More...

virtual uint8_t	readByte (uint8_t offset)
	Reads the byte at offset within the realtime clock's non-volatile memory. More...

virtual void	writeByte (uint8_t offset, uint8_t value)
	Writes value to offset within the realtime clock's non-volatile memory. More...

Additional Inherited Members
Public Types inherited from RTC
enum	DayOfWeek { Monday = 1, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday }
	Day of the week corresponding to a date. More...

Static Public Member Functions inherited from RTC
static void	adjustDays (RTCDate *date, uint8_t flags)
	Adjusts date up or down one day according to flags. More...

static void	adjustMonths (RTCDate *date, uint8_t flags)
	Adjusts date up or down one month according to flags. More...

static void	adjustYears (RTCDate *date, uint8_t flags)
	Adjusts date up or down one year according to flags. More...

static DayOfWeek	dayOfWeek (const RTCDate *date)
	Returns the day of the week corresponding to date. More...

Static Public Attributes inherited from RTC
static const uint8_t	ALARM_COUNT = 4
	Number of alarms that are supported by RTC::readAlarm() and RTC::writeAlarm().

static const int	NO_TEMPERATURE = 32767
	Value that is returned from readTemperature() if the realtime clock chip cannot determine the temperature.

static const uint8_t	INCREMENT = 0x0000
	Increment the day, month, or year in a call to adjustDays(), adjustMonths(), or adjustYears().

static const uint8_t	DECREMENT = 0x0001
	Decrement the day, month, or year in a call to adjustDays(), adjustMonths(), or adjustYears().

static const uint8_t	WRAP = 0x0002
	Wrap around to the beginning of the current month/year rather than advance to the next one.

Detailed Description

Communicates with a DS3231 realtime clock chip via I2C.

This class simplifies the process of reading and writing the time and date information in a DS3231 realtime clock chip. The class also provides support for reading and writing information about alarms and other clock settings.

If there is no DS3231 chip on the I2C bus, this class will fall back to the RTC class to simulate the current time and date based on the value of millis().

Alarms 0 and 1 can be set to generate an interrupt when they fire using enableAlarmInterrupts(). The firedAlarm() function can be used to determine which alarm has fired.

The DS3231 uses a 2-digit year so this class is limited to dates between 2000 and 2099 inclusive.

The structure RTCAlarm is used to read and write the alarms. It has a flags field which is analogous to the alarm mask bits found in the DS3231 manual. Bit 7 signals whether this is an alarm structure with settings for alarm 0 or 1 (as these are different, see manual).

See Also: RTC, DS3232RTC, DS1307RTC

Definition at line 35 of file DS3231RTC.h.

Constructor & Destructor Documentation

DS3231RTC::DS3231RTC	(	I2CMaster &	bus,
		uint8_t	oneHzPin = `255`
	)

Attaches to a realtime clock slave device on bus.

If oneHzPin is not 255, then it indicates a digital input pin that is connected to the 1 Hz square wave output on the realtime clock. This input is used by hasUpdates() to determine if the time information has changed in a non-trivial manner.

If you wish to use enableAlarmInterrupts(), then oneHzPin must be 255.

See Also: hasUpdates(), enableAlarmInterrupts()

Definition at line 125 of file DS3231RTC.cpp.

Member Function Documentation

void DS3231RTC::disable32kHzOutput ( )

Disables the 32 kHz output on the DS3231 chip.

See Also: enable32kHzOutput()

Definition at line 575 of file DS3231RTC.cpp.

void DS3231RTC::disableAlarm ( uint8_t alarmNum )

Disables a specific alarm.

Parameters

alarmNum The alarm to disable.

See Also: enableAlarm()

Definition at line 625 of file DS3231RTC.cpp.

void DS3231RTC::disableAlarmInterrupts ( )

Disables the generation of interrupts for alarms 0 and 1.

See Also: enableAlarmInterrupts()

Definition at line 508 of file DS3231RTC.cpp.

void DS3231RTC::enable32kHzOutput ( )

Enables the 32 kHz output on the DS3231 chip.

See Also: disable32kHzOutput()

Definition at line 562 of file DS3231RTC.cpp.

void DS3231RTC::enableAlarm ( uint8_t alarmNum )

Enables a specific alarm.

Parameters

alarmNum The alarm to enable.

See Also: disableAlarm()

Definition at line 606 of file DS3231RTC.cpp.

void DS3231RTC::enableAlarmInterrupts ( )

Enables the generation of interrupts for alarms 0 and 1.

When the interrupt occurs, use firedAlarm() to determine which alarm has fired. The application is responsible for implementing the interrupt service routine to watch for the interrupt.

Note: this function does nothing if the 1 Hz pin was enabled in the constructor, but firedAlarm() can still be used to determine which alarm has fired when hasUpdates() reports that there is an update available.

See Also: disableAlarmInterrupts(), firedAlarm()

Definition at line 494 of file DS3231RTC.cpp.

int DS3231RTC::firedAlarm ( )

Determines which of alarms 0 or 1 have fired since the last call.

Returns 0 if alarm 0 has fired, 1 if alarm 1 has fired, 2 if both alarms have fired, or -1 if neither alarm has fired.

The fired alarm state will be cleared, ready for the next call.

This function cannot be used to determine if alarms 2 or 3 have fired as they are stored in NVRAM and are not handled specially by the DS3231.

See Also: enableAlarmInterrupts()

Definition at line 530 of file DS3231RTC.cpp.

void DS3231RTC::readAlarm	(	uint8_t	alarmNum,
		RTCAlarm *	value
	)

virtual

Reads the details of the alarm with index alarmNum into value.

The alarmNum parameter must be between 0 and ALARM_COUNT - 1.

Alarm details are stored at the end of the realtime clock's non-volatile memory.

See Also: writeAlarm(), alarmCount()

Reimplemented from RTC.

Definition at line 280 of file DS3231RTC.cpp.

void DS3231RTC::readDate ( RTCDate * value )

virtual

Reads the current date from the realtime clock into value.

The time should be read first with readTime() as the default implementation only advances the date when the time is read and it crosses midnight.

See Also: writeDate(), readTime()

Reimplemented from RTC.

Definition at line 228 of file DS3231RTC.cpp.

int DS3231RTC::readTemperature ( )

virtual

Reads the value of the temperature sensor and returns the temperature in quarters of a degree celcius.

Returns the value NO_TEMPERATURE if the realtime clock chip cannot determine the temperature.

Reimplemented from RTC.

Definition at line 470 of file DS3231RTC.cpp.

void DS3231RTC::readTime ( RTCTime * value )

virtual

Reads the current time from the realtime clock into value.

See Also: writeTime(), readDate()

Reimplemented from RTC.

Definition at line 207 of file DS3231RTC.cpp.

bool DS3231RTC::setAlarm	(	uint8_t	alarmNum,
		const RTCAlarm *	value
	)

Sets the alarm with index alarmNum from value.

The alarmNum parameter must be between 0 and ALARM_COUNT - 1.

Returns: Returns true if the alarm was set; false otherwise.

See Also: writeAlarm()

Definition at line 408 of file DS3231RTC.cpp.

void DS3231RTC::writeAlarm	(	uint8_t	alarmNum,
		const RTCAlarm *	value
	)

virtual

Updates the details of the alarm with index alarmNum from value.

The alarmNum parameter must be between 0 and ALARM_COUNT - 1.

Alarm details are stored at the end of the realtime clock's non-volatile memory.

See Also: readAlarm(), alarmCount()

Reimplemented from RTC.

Definition at line 374 of file DS3231RTC.cpp.

void DS3231RTC::writeDate ( const RTCDate * value )

virtual

Updates the date in the realtime clock to match value.

See Also: readDate(), writeTime()

Reimplemented from RTC.

Definition at line 266 of file DS3231RTC.cpp.

void DS3231RTC::writeTime ( const RTCTime * value )

virtual

Updates the time in the realtime clock to match value.

See Also: readTime(), writeDate()

Reimplemented from RTC.

Definition at line 252 of file DS3231RTC.cpp.

The documentation for this class was generated from the following files:

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation