I2C device interface for communicating with I2C peripheral devices. More...

#include <i2cdev.h>

Inheritance diagram for Piduino::I2cDev:

Collaboration diagram for Piduino::I2cDev:

Classes
class	Info
	Information class for I2C bus configuration and management. More...

Public Types
enum	OpenModeFlag { NotOpen = 0x0000 , Append = std::ios_base::app , AtEnd = std::ios_base::ate , Binary = std::ios_base::binary , ReadOnly = std::ios_base::in , WriteOnly = std::ios_base::out , ReadWrite = ReadOnly \| WriteOnly , Truncate = std::ios_base::trunc , IosModes = Append \| AtEnd \| Binary \| ReadOnly \| WriteOnly \| Truncate , Unbuffered = (Truncate << 1) }
	Flags that specify how the device is to be opened. More...

typedef Flags< OpenModeFlag >	OpenMode
	Type representing a combination of OpenModeFlag values.

Public Member Functions
	I2cDev ()
	Default constructor that creates an I2cDev object without specifying a bus. The bus must be set later using setBus() before opening the device.

	I2cDev (const Info &bus)
	Constructs an I2cDev object for the specified I2C bus.

	I2cDev (const char *path)
	Constructs an I2cDev object using a device path.

	I2cDev (const std::string &path)
	Constructs an I2cDev object using a device path.

	I2cDev (int idBus)
	Constructs an I2cDev object for the specified bus ID.

virtual	~I2cDev ()
	Virtual destructor that properly cleans up the I2C device.

virtual bool	open (OpenMode mode=IoDevice::ReadWrite)
	Opens the I2C device for communication.

virtual void	close ()
	Closes the I2C device and releases system resources.

void	setBus (const Info &bus)
	Sets the I2C bus using an Info object.

void	setBus (int idBus)
	Sets the I2C bus using a bus ID.

const Info &	bus () const
	Gets the current I2C bus information.

void	setBusPath (const char *path)
	Sets the I2C bus using a device path.

void	setBusPath (const std::string &path)
	Sets the I2C bus using a device path.

void	beginTransmission (uint16_t slave)
	Begins an I2C transmission to the specified slave device. This must be called before writing data to a slave device. This function sets the slave address for the transaction and initializes the internal buffer but it does not send any data yet.

bool	endTransmission (bool stop=true)
	Ends the current I2C transmission and sends the data if stop is true.

virtual int	write (uint8_t data)
	Writes a single byte to the current I2C transaction buffer.

virtual int	write (const uint8_t *buffer, uint16_t len)
	Writes multiple bytes to the current I2C transaction buffer.

int	write (std::string str)
	Writes a string to the current I2C transaction buffer.

int	write (const char *str)
	Writes a C-style string to the current I2C transaction buffer.

int	write (int data)
	Writes an integer value (cast to uint8_t) to the current I2C transaction buffer.

int	write (unsigned int data)
	Writes an unsigned integer value (cast to uint8_t) to the current I2C transaction buffer.

int	write (long data)
	Writes a long value (cast to uint8_t) to the current I2C transaction buffer.

int	write (unsigned long data)
	Writes an unsigned long value (cast to uint8_t) to the current I2C transaction buffer.

int	requestFrom (uint16_t slave, uint16_t max, bool stop=true)
	Requests data from an I2C slave device and stores it in the read buffer.

int	requestFrom (int slave, int max, int stop=1)
	Requests data from an I2C slave device (convenience overload with int parameters).

uint16_t	available () const
	Gets the number of bytes available for reading from the internal buffer.

virtual int	read (uint8_t *buffer, uint16_t max)
	Reads data from the internal buffer into the provided buffer.

virtual int	read ()
	Reads a single byte from the internal buffer.

virtual int	peek () const
	Peeks at the next byte in the buffer without removing it.

virtual void	flush ()
	Flushes any pending data in the internal buffers. This ensures all data is sent before returning.

OpenMode	openMode () const
	Returns the current open mode of the device.

virtual bool	isOpen () const
	Returns true if the device is currently open.

bool	isReadable () const
	Returns true if the device is readable.

bool	isWritable () const
	Returns true if the device is writable.

bool	isBuffered () const
	Returns true if the device is buffered.

virtual bool	isSequential () const
	Returns true if this device is sequential; otherwise returns false.

void	setTextModeEnabled (bool enabled)
	Enables or disables text mode for the device.

bool	isTextModeEnabled () const
	Returns true if text mode is enabled.

void	setDebug (bool enabled)
	Enables or disables debug mode for the device.

bool	isDebug () const
	Returns true if debug mode is enabled.

virtual std::string	errorString () const
	Returns a human-readable description of the last error.

virtual int	error () const
	Returns the code of the last error.

Static Public Member Functions
static std::shared_ptr< I2cDev >	factory (int busId)
	Factory method that creates a shared pointer to an I2cDev instance.

Protected Member Functions
	I2cDev (Private &dd)
	Protected constructor for derived classes using the PIMPL pattern.

Protected Attributes
std::unique_ptr< Private >	d_ptr
	Pointer to the private implementation.

Detailed Description

I2C device interface for communicating with I2C peripheral devices.

This class provides a high-level interface for I2C communication on Linux systems. It supports master mode operations including reading from and writing to I2C slave devices. The class handles I2C bus management, transaction control, and data buffering.

Definition at line 35 of file i2cdev.h.

Member Typedef Documentation

◆ OpenMode

Piduino::IoDevice::OpenMode

inherited

Type representing a combination of OpenModeFlag values.

Definition at line 70 of file iodevice.h.

Member Enumeration Documentation

◆ OpenModeFlag

enum Piduino::IoDevice::OpenModeFlag

inherited

Flags that specify how the device is to be opened.

These flags control the behavior of the device when it is opened. They can be combined using bitwise OR.

Enumerator
NotOpen	Device is not open.
Append	Set the stream's position indicator to the end of the stream before each output operation.
AtEnd	Set the stream's position indicator to the end of the stream on opening.
Binary	Open the device in binary mode (no text translation).
ReadOnly	Open the device for input operations only. Text mode: When reading, end-of-line terminators are translated to ' '. When writing, end-of-line terminators are translated to the local encoding (e.g., '\r ' for Win32).
WriteOnly	Open the device for output operations only.
ReadWrite	Open the device for both input and output operations.
Truncate	Discard any existing content when opening the device.
IosModes	Combination of all standard I/O modes.
Unbuffered	Open the device in unbuffered mode (implementation-defined).

Definition at line 48 of file iodevice.h.

Constructor & Destructor Documentation

◆ I2cDev() [1/6]

Piduino::I2cDev::I2cDev ( )

Default constructor that creates an I2cDev object without specifying a bus. The bus must be set later using setBus() before opening the device.

◆ I2cDev() [2/6]

Piduino::I2cDev::I2cDev ( const Info & bus )

Constructs an I2cDev object for the specified I2C bus.

Parameters

bus	The I2C bus information

◆ I2cDev() [3/6]

Piduino::I2cDev::I2cDev ( const char * path )

explicit

Constructs an I2cDev object using a device path.

Parameters

path	The device path (e.g., "/dev/i2c-0")

◆ I2cDev() [4/6]

Piduino::I2cDev::I2cDev ( const std::string & path )

explicit

Constructs an I2cDev object using a device path.

Parameters

path	The device path as a string

◆ I2cDev() [5/6]

Piduino::I2cDev::I2cDev ( int idBus )

explicit

Constructs an I2cDev object for the specified bus ID.

Parameters

idBus The I2C bus ID

◆ ~I2cDev()

virtual Piduino::I2cDev::~I2cDev ( )

virtual

Virtual destructor that properly cleans up the I2C device.

◆ I2cDev() [6/6]

Piduino::I2cDev::I2cDev ( Private & dd )

protected

Protected constructor for derived classes using the PIMPL pattern.

Parameters

dd	Reference to the private implementation

Member Function Documentation

◆ available()

uint16_t Piduino::I2cDev::available ( ) const

Gets the number of bytes available for reading from the internal buffer.

Returns: The number of bytes available

◆ beginTransmission()

void Piduino::I2cDev::beginTransmission ( uint16_t slave )

Begins an I2C transmission to the specified slave device. This must be called before writing data to a slave device. This function sets the slave address for the transaction and initializes the internal buffer but it does not send any data yet.

Parameters

slave The 7-bit I2C slave address

◆ bus()

const Info & Piduino::I2cDev::bus ( ) const

Gets the current I2C bus information.

Returns: A reference to the current bus Info object

◆ close()

virtual void Piduino::I2cDev::close ( )

virtual

Closes the I2C device and releases system resources.

Reimplemented from Piduino::IoDevice.

◆ endTransmission()

bool Piduino::I2cDev::endTransmission ( bool stop = true )

Ends the current I2C transmission and sends the data if stop is true.

This function sends the data accumulated with write() in the internal buffer only if stop is true. If stop is false, the transmission is not finalized, allowing for further data to be added (e.g. for reading).

Parameters

stop	Whether to send a stop condition (default: true)

Returns: true if the transmission was successful, false otherwise

◆ error()

virtual int Piduino::IoDevice::error ( ) const

virtualinherited

Returns the code of the last error.

Returns: The error code.

◆ errorString()

virtual std::string Piduino::IoDevice::errorString ( ) const

virtualinherited

Returns a human-readable description of the last error.

Returns: The error string.

◆ factory()

static std::shared_ptr< I2cDev > Piduino::I2cDev::factory ( int busId )

static

Factory method that creates a shared pointer to an I2cDev instance.

This method is used to create an I2cDev object for a specific I2C bus ID and shares the instance across the application. It ensures that only one instance per bus ID exists.

Parameters

busId The I2C bus ID

Returns: A shared pointer to the created I2cDev object

◆ flush()

virtual void Piduino::I2cDev::flush ( )

virtual

Flushes any pending data in the internal buffers. This ensures all data is sent before returning.

◆ isBuffered()

bool Piduino::IoDevice::isBuffered ( ) const

inherited

Returns true if the device is buffered.

Returns: True if buffered, false otherwise.

◆ isDebug()

bool Piduino::IoDevice::isDebug ( ) const

inherited

Returns true if debug mode is enabled.

Returns: True if debug mode is enabled, false otherwise.

◆ isOpen()

virtual bool Piduino::IoDevice::isOpen ( ) const

virtualinherited

Returns true if the device is currently open.

Returns: True if open, false otherwise.

◆ isReadable()

bool Piduino::IoDevice::isReadable ( ) const

inherited

Returns true if the device is readable.

Returns: True if readable, false otherwise.

◆ isSequential()

virtual bool Piduino::IoDevice::isSequential ( ) const

virtualinherited

Returns true if this device is sequential; otherwise returns false.

Sequential devices, as opposed to random-access devices, have no concept of a start, an end, a size, or a current position, and do not support seeking. You can only read from the device when it reports that data is available. The most common example of a sequential device is a network socket. On Unix, special files such as /dev/zero and fifo pipes are sequential. Regular files, on the other hand, do support random access. They have both a size and a current position, and they also support seeking backwards and forwards in the data stream. Regular files are non-sequential.

The IoDevice implementation returns false.

Returns: True if the device is sequential, false otherwise.

◆ isTextModeEnabled()

bool Piduino::IoDevice::isTextModeEnabled ( ) const

inherited

Returns true if text mode is enabled.

Returns: True if text mode is enabled, false otherwise.

◆ isWritable()

bool Piduino::IoDevice::isWritable ( ) const

inherited

Returns true if the device is writable.

Returns: True if writable, false otherwise.

◆ open()

virtual bool Piduino::I2cDev::open ( OpenMode mode = IoDevice::ReadWrite )

virtual

Opens the I2C device for communication.

Parameters

mode	The opening mode (default: ReadWrite)

Returns: true if the device was successfully opened, false otherwise

Reimplemented from Piduino::IoDevice.

◆ openMode()

OpenMode Piduino::IoDevice::openMode ( ) const

inherited

Returns the current open mode of the device.

Returns: The open mode flags.

◆ peek()

virtual int Piduino::I2cDev::peek ( ) const

virtual

Peeks at the next byte in the buffer without removing it.

Returns: The next byte, or -1 if no data is available

◆ read() [1/2]

virtual int Piduino::I2cDev::read ( )

virtual

Reads a single byte from the internal buffer.

Returns: The byte read, or -1 if no data is available

◆ read() [2/2]

virtual int Piduino::I2cDev::read	(	uint8_t *	buffer,
		uint16_t	max
	)

virtual

Reads data from the internal buffer into the provided buffer.

Parameters

buffer	Pointer to the destination buffer
max	Maximum number of bytes to read

Returns: The number of bytes actually read

◆ requestFrom() [1/2]

int Piduino::I2cDev::requestFrom	(	int	slave,
		int	max,
		int	stop = `1`
	)

inline

Requests data from an I2C slave device (convenience overload with int parameters).

This function initiates a read transaction from the specified I2C slave device, but does not transfer any data yet, even if the stop parameter is true.

Parameters

slave	The I2C slave address
max	The maximum number of bytes to request
stop	Whether to send a stop condition (1 = true, 0 = false, default: 1)

Returns: The number of bytes actually received, or -1 on error

◆ requestFrom() [2/2]

int Piduino::I2cDev::requestFrom	(	uint16_t	slave,
		uint16_t	max,
		bool	stop = `true`
	)

Requests data from an I2C slave device and stores it in the read buffer.

This function initiates a read transaction from the specified I2C slave device, but does not transfer any data yet, even if the stop parameter is true.

Parameters

slave	The 7-bit I2C slave address
max	The maximum number of bytes to request
stop	Whether to send a stop condition after the transaction (default: true)

Returns: The number of bytes actually received, or -1 on error

◆ setBus() [1/2]

void Piduino::I2cDev::setBus ( const Info & bus )

Sets the I2C bus using an Info object.

Parameters

bus	The I2C bus information

◆ setBus() [2/2]

void Piduino::I2cDev::setBus ( int idBus )

Sets the I2C bus using a bus ID.

Parameters

idBus The I2C bus ID

◆ setBusPath() [1/2]

void Piduino::I2cDev::setBusPath ( const char * path )

Sets the I2C bus using a device path.

Parameters

path	The device path (e.g., "/dev/i2c-0")

◆ setBusPath() [2/2]

void Piduino::I2cDev::setBusPath ( const std::string & path )

Sets the I2C bus using a device path.

Parameters

path	The device path as a string

◆ setDebug()

void Piduino::IoDevice::setDebug ( bool enabled )

inherited

Enables or disables debug mode for the device.

Parameters

enabled True to enable debug mode, false to disable.

◆ setTextModeEnabled()

void Piduino::IoDevice::setTextModeEnabled ( bool enabled )

inherited

Enables or disables text mode for the device.

Parameters

enabled True to enable text mode, false to disable.

◆ write() [1/8]

int Piduino::I2cDev::write ( const char * str )

inline

Writes a C-style string to the current I2C transaction buffer.

Parameters

str	The null-terminated string to write

Returns: The number of bytes successfully written

◆ write() [2/8]

virtual int Piduino::I2cDev::write	(	const uint8_t *	buffer,
		uint16_t	len
	)

virtual

Writes multiple bytes to the current I2C transaction buffer.

Parameters

buffer	Pointer to the data buffer
len	Number of bytes to write

Returns: The number of bytes successfully written

◆ write() [3/8]

int Piduino::I2cDev::write ( int data )

inline

Writes an integer value (cast to uint8_t) to the current I2C transaction buffer.

Parameters

data	The integer value to write

Returns: 1 if successful, 0 if the buffer is full

◆ write() [4/8]

int Piduino::I2cDev::write ( long data )

inline

Writes a long value (cast to uint8_t) to the current I2C transaction buffer.

Parameters

data	The long value to write

Returns: 1 if successful, 0 if the buffer is full

◆ write() [5/8]

int Piduino::I2cDev::write ( std::string str )

inline

Writes a string to the current I2C transaction buffer.

Parameters

str	The string to write

Returns: The number of bytes successfully written

◆ write() [6/8]

virtual int Piduino::I2cDev::write ( uint8_t data )

virtual

Writes a single byte to the current I2C transaction buffer.

Parameters

data	The byte to write

Returns: 1 if successful, 0 if the buffer is full

◆ write() [7/8]

int Piduino::I2cDev::write ( unsigned int data )

inline

Writes an unsigned integer value (cast to uint8_t) to the current I2C transaction buffer.

Parameters

data	The unsigned integer value to write

Returns: 1 if successful, 0 if the buffer is full

◆ write() [8/8]

int Piduino::I2cDev::write ( unsigned long data )

inline

Writes an unsigned long value (cast to uint8_t) to the current I2C transaction buffer.

Parameters

data	The unsigned long value to write

Returns: 1 if successful, 0 if the buffer is full

Member Data Documentation

◆ d_ptr

std::unique_ptr<Private> Piduino::IoDevice::d_ptr

protectedinherited

Pointer to the private implementation.

Definition at line 190 of file iodevice.h.

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ OpenMode

Member Enumeration Documentation

◆ OpenModeFlag

Constructor & Destructor Documentation

◆ I2cDev() [1/6]

◆ I2cDev() [2/6]

◆ I2cDev() [3/6]

◆ I2cDev() [4/6]

◆ I2cDev() [5/6]

◆ ~I2cDev()

◆ I2cDev() [6/6]

Member Function Documentation

◆ available()

◆ beginTransmission()

◆ bus()

◆ close()

◆ endTransmission()

◆ error()

◆ errorString()

◆ factory()

◆ flush()

◆ isBuffered()

◆ isDebug()

◆ isOpen()

◆ isReadable()

◆ isSequential()

◆ isTextModeEnabled()

◆ isWritable()

◆ open()

◆ openMode()

◆ peek()

◆ read() [1/2]

◆ read() [2/2]

◆ requestFrom() [1/2]

◆ requestFrom() [2/2]

◆ setBus() [1/2]

◆ setBus() [2/2]

◆ setBusPath() [1/2]

◆ setBusPath() [2/2]

◆ setDebug()

◆ setTextModeEnabled()

◆ write() [1/8]

◆ write() [2/8]

◆ write() [3/8]

◆ write() [4/8]

◆ write() [5/8]

◆ write() [6/8]

◆ write() [7/8]

◆ write() [8/8]

Member Data Documentation

◆ d_ptr