#include <TWI.h>

Inheritance diagram for Software::TWI< SDA_PIN, SCL_PIN >:

Collaboration diagram for Software::TWI< SDA_PIN, SCL_PIN >:

Public Member Functions
	TWI ()

virtual bool	acquire ()

virtual bool	release ()

virtual int	read (uint8_t addr, void *buf, size_t count)

virtual int	write (uint8_t addr, iovec_t *vp)

virtual int	write (uint8_t addr, const void *buf, size_t count)

Static Public Attributes
static const uint32_t	DEFAULT_FREQ = 100000L

Protected Member Functions
bool	clock_stretching ()

bool	start_condition ()

bool	repeated_start_condition ()

bool	stop_condition ()

bool	write_bit (bool value)

bool	read_bit (bool &value)

bool	write_byte (uint8_t byte, bool &nack)

bool	read_byte (uint8_t &byte, bool ack)

void	lock ()

void	unlock ()

Protected Attributes
GPIO< SDA_PIN >	m_sda

GPIO< SCL_PIN >	m_scl

bool	m_start

volatile bool	m_busy

Static Protected Attributes
static const int	T1 = 4

static const int	T2 = 5

static const int	CLOCK_STRETCHING_RETRY_MAX = 25

Detailed Description

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>
class Software::TWI< SDA_PIN, SCL_PIN >

Definition at line 32 of file TWI.h.

Constructor & Destructor Documentation

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

Software::TWI< SDA_PIN, SCL_PIN >::TWI ( )

inline

Construct Two-Wire Interface (TWI) instance with given template parameters. Initiate GPIO pins for data and clock for open drain mode.

Definition at line 39 of file TWI.h.

Member Function Documentation

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

virtual bool Software::TWI< SDA_PIN, SCL_PIN >::acquire ( )

inlinevirtual

Start transaction for given device driver. Return true(1) if successful otherwise false(0).

Returns: bool.

Implements TWI.

Definition at line 51 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::clock_stretching ( )

inlineprotected

Allow device to stretch clock signal. Return true(1) if successful otherwise false(0).

Returns: bool.

Definition at line 158 of file TWI.h.

void TWI::lock ( )

inlineprotectedinherited

Lock bus manager.

Definition at line 176 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

virtual int Software::TWI< SDA_PIN, SCL_PIN >::read	(	uint8_t	addr,
		void *	buf,
		size_t	count
	)

inlinevirtual

Read data from device with given address into given buffer.

Parameters

[in]	addr	device address.
[in]	buf	buffer pointer.
[in]	count	buffer size in bytes.

Returns: number of bytes read or negative error code.

Implements TWI.

Definition at line 80 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::read_bit ( bool & value )

inlineprotected

Read bit to device. Return true(1) if successful otherwise false(0).

Parameters

[out] value read from device.

Returns: bool.

Definition at line 239 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::read_byte	(	uint8_t &	byte,
		bool	ack
	)

inlineprotected

Read byte to device. Return true(1) if successful otherwise false(0). The parameter ack signals if additional read with follow.

Parameters

[in]	byte	to write to device.
[out]	ack	to device.

Returns: bool.

Definition at line 275 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

virtual bool Software::TWI< SDA_PIN, SCL_PIN >::release ( )

inlinevirtual

Stop transaction. Mark the bus as available. Return true(1) if successful otherwise false(0).

Returns: bool.

Implements TWI.

Definition at line 65 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::repeated_start_condition ( )

inlineprotected

Generate repeated start condition. Return true(1) if successful otherwise false(0).

Returns: bool.

Definition at line 187 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::start_condition ( )

inlineprotected

Generate start condition. Return true(1) if successful otherwise false(0).

Returns: bool.

Definition at line 172 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::stop_condition ( )

inlineprotected

Generate stop condition. Return true(1) if successful otherwise false(0).

Returns: bool.

Definition at line 205 of file TWI.h.

void TWI::unlock ( )

inlineprotectedinherited

Unlock bus manager.

Definition at line 185 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

virtual int Software::TWI< SDA_PIN, SCL_PIN >::write	(	uint8_t	addr,
		iovec_t *	vp
	)

inlinevirtual

Write data to device with from given io vector.

Parameters

[in]	addr	device address.
[in]	vp	io vector pointer.

Returns: number of bytes written or negative error code.

Implements TWI.

Definition at line 109 of file TWI.h.

virtual int TWI::write	(	uint8_t	addr,
		const void *	buf,
		size_t	count
	)

inlinevirtualinherited

Write data to device with given address from given buffer.

Parameters

[in]	addr	device address.
[in]	buf	buffer pointer.
[in]	count	buffer size in bytes.

Returns: number of bytes written or negative error code.

Definition at line 151 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::write_bit ( bool value )

inlineprotected

Write bit to device. Return true(1) if successful otherwise false(0).

Parameters

[in] value to write to device.

Returns: bool.

Definition at line 222 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::write_byte	(	uint8_t	byte,
		bool &	nack
	)

inlineprotected

Write byte to device. Return true(1) and nack bit if successful otherwise false(0).

Parameters

[in]	byte	to write to device.
[out]	nack	from device.

Returns: bool.

Definition at line 258 of file TWI.h.

Member Data Documentation

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

const int Software::TWI< SDA_PIN, SCL_PIN >::CLOCK_STRETCHING_RETRY_MAX = 25

staticprotected

Maximum number of clock stretching retries: 100 us

Definition at line 142 of file TWI.h.

const uint32_t TWI::DEFAULT_FREQ = 100000L

staticinherited

Default Two-Wire Interface clock: 100 KHz.

Definition at line 108 of file TWI.h.

volatile bool TWI::m_busy

protectedinherited

Bus manager semaphore.

Definition at line 171 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

GPIO<SCL_PIN> Software::TWI< SDA_PIN, SCL_PIN >::m_scl

protected

Clock signal pin.

Definition at line 148 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

GPIO<SDA_PIN> Software::TWI< SDA_PIN, SCL_PIN >::m_sda

protected

Data signal pin.

Definition at line 145 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

bool Software::TWI< SDA_PIN, SCL_PIN >::m_start

protected

Transaction state; start or repeated start condition.

Definition at line 151 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

const int Software::TWI< SDA_PIN, SCL_PIN >::T1 = 4

staticprotected

Start condition delay time: 4.0 us (100 kHz)

Definition at line 136 of file TWI.h.

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>

const int Software::TWI< SDA_PIN, SCL_PIN >::T2 = 5

staticprotected

Basic clock delay time: 4.7 us (100 kHz)

Definition at line 139 of file TWI.h.

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

src/Software/TWI.h

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN> class Software::TWI< SDA_PIN, SCL_PIN >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<BOARD::pin_t SDA_PIN, BOARD::pin_t SCL_PIN>
class Software::TWI< SDA_PIN, SCL_PIN >