MCP7940N Class Reference

#include <MCP7940N.hh>

Inheritance diagram for MCP7940N:

Collaboration diagram for MCP7940N:

Classes
struct	alarm_t
class	AlarmInterrupt
union	config_t
union	control_t
struct	rtcc_t
struct	timestamp_t

Public Types
enum	{ SQW_1_HZ, SQW_4_096_KHZ, SQW_8_192_KHZ, SQW_32_768_KHZ }
enum	{   WHEN_SEC_MATCH = 0x00, WHEN_MIN_MATCH = 0x01, WHEN_HOUR_MATCH = 0x02, WHEN_DAY_MATCH = 0x03,   WHEN_DATE_MATCH = 0x04, WHEN_TIME_MATCH = 0x07 }

Public Member Functions
	MCP7940N (Board::ExternalInterruptPin pin=Board::EXT1)
bool	get_time (time_t &now)
bool	set_time (time_t &now)
bool	set_alarm (uint8_t nr, time_t &alarm, uint8_t when)
bool	get_alarm (uint8_t nr, time_t &alarm, uint8_t &when)
bool	clear_alarm (uint8_t nr)
uint8_t	pending_alarm ()
bool	square_wave (bool flag)

Static Public Attributes
static const uint8_t	RAM_START = sizeof(rtcc_t)
static const uint8_t	RAM_END = 0x5f
static const uint8_t	RAM_MAX = RAM_END - RAM_START + 1

Protected Member Functions
int	read (void *regs, uint8_t size, uint8_t pos=0)
int	write (void *regs, uint8_t size, uint8_t pos=0)

Protected Attributes
AlarmInterrupt	m_alarm_irq

Private Member Functions
bool	is_async () const
void	sync_request ()
void	async_request ()
virtual void	on_completion (uint8_t type, int count)

Private Attributes
uint8_t	m_addr
bool	m_async

Detailed Description

Driver for the MCP7940N, Low-Cost I2C Real-Time Clock/Calendar (RTCC) with SRAM and Battery Switchover.

References

1. Microchip MCP7940N data sheet; http://ww1.microchip.com/downloads/en/DeviceDoc/20005010F.pdf

Definition at line 37 of file MCP7940N.hh.

Member Enumeration Documentation

anonymous enum

Rate Selection in control register (rs, pp. 10).

Enumerator
SQW_1_HZ	1 Hz
SQW_4_096_KHZ	4.096 Hz
SQW_8_192_KHZ	8.192 Hz
SQW_32_768_KHZ	32.768 Hz

Definition at line 80 of file MCP7940N.hh.

anonymous enum

Alarm match types (pp. 10-11).

Enumerator
WHEN_SEC_MATCH	Seconds match.
WHEN_MIN_MATCH	Minutes match.
WHEN_HOUR_MATCH	Hours match (takes into accout 12/24 hour).
WHEN_DAY_MATCH	Matches the current Day.
WHEN_DATE_MATCH	Date.
WHEN_TIME_MATCH	Sec, Min, Hour, Day, Date, Month.

Definition at line 139 of file MCP7940N.hh.

Constructor & Destructor Documentation

MCP7940N::MCP7940N ( Board::ExternalInterruptPin  pin = Board::EXT1 )

inline

Construct MCP7940N device with bus address(0x6f).

Parameters

[in]

pin

alarm interrupt pin (Default EXT1/EXT0).

Definition at line 210 of file MCP7940N.hh.

Member Function Documentation

bool MCP7940N::clear_alarm

(

uint8_t

nr

)

Clear given real-time clock alarm. Return true(1) if successful otherwise false(0).

Parameters

[in]

nr

alarm number (0..1).

Returns

boolean.

Definition at line 146 of file MCP7940N.cpp.

bool MCP7940N::get_alarm	(	uint8_t	nr,
		time_t &	alarm,
		uint8_t &	when
	)

Read given real-time clock alarm time and configuration. Return true(1) if successful otherwise false(0).

Parameters

[in]	nr	alarm number (0..1).
[out]	alarm	time structure.
[out]	when	alarm should trigger.

Returns

boolean.

Definition at line 75 of file MCP7940N.cpp.

bool MCP7940N::get_time

(

time_t &

now

)

Read current time from real-time clock. Return true(1) if successful otherwise false(0).

Parameters

[out]

now

time structure return value.

Returns

boolean.

Definition at line 56 of file MCP7940N.cpp.

uint8_t MCP7940N::pending_alarm

(

)

Check any pending alarms (signalled on interrupt pin). Returns alarm pending (0 for no alarms, 1 for alarm0, 2 for alarm1 and 3 for both)

Returns

alarm triggered or zero for no alarms pending.

Definition at line 124 of file MCP7940N.cpp.

int MCP7940N::read ( void *  regs, uint8_t  size, uint8_t  pos = 0  )

protected

Read register block with the given size into the buffer from the position. Return number of bytes read or negative error code.

Parameters

[in]	regs	buffer to read from register block.
[in]	size	number of bytes to read.
[in]	pos	address in register file to read from.

Returns

number of bytes or negative error code.

Definition at line 37 of file MCP7940N.cpp.

bool MCP7940N::set_alarm	(	uint8_t	nr,
		time_t &	alarm,
		uint8_t	when
	)

Set given real-time clock alarm with the given time and configuration. Return true(1) if successful otherwise false(0).

Parameters

[in]	nr	alarm number (0..1).
[in]	alarm	time structure to set.
[in]	when	alarm should trigger.

Returns

boolean.

Definition at line 93 of file MCP7940N.cpp.

bool MCP7940N::set_time

(

time_t &

now

)

Set the real-time clock to the given time. Return true(1) if successful otherwise false(0).

Parameters

[in]

now

time structure to set.

Returns

boolean.

Definition at line 66 of file MCP7940N.cpp.

bool MCP7940N::square_wave

(

bool

flag

)

Enable/disable square_wave generation.

Parameters

[in]

flag.

Definition at line 165 of file MCP7940N.cpp.

int MCP7940N::write ( void *  regs, uint8_t  size, uint8_t  pos = 0  )

protected

Write register block at given position with the contents from buffer. Return number of bytes written or negative error code.

Parameters

[in]	regs	buffer to write to register block.
[in]	size	number of bytes to write.
[in]	pos	address in register file to read write to.

Returns

number of bytes or negative error code.

Definition at line 47 of file MCP7940N.cpp.

Member Data Documentation

AlarmInterrupt MCP7940N::m_alarm_irq

protected

Alarm Interrupt Pin

Definition at line 313 of file MCP7940N.hh.

const uint8_t MCP7940N::RAM_END = 0x5f

static

End of application RAM.

Definition at line 200 of file MCP7940N.hh.

const uint8_t MCP7940N::RAM_MAX = RAM_END - RAM_START + 1

static

Max size of application RAM (64 bytes).

Definition at line 203 of file MCP7940N.hh.

const uint8_t MCP7940N::RAM_START = sizeof(rtcc_t)

static

Start of application RAM.

Definition at line 197 of file MCP7940N.hh.

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

• libraries/MCP7940N/MCP7940N.hh
• libraries/MCP7940N/MCP7940N.cpp