TwoWire Class Reference

#include <Wire.h>

Inheritance diagram for TwoWire:

Collaboration diagram for TwoWire:

Public Types
enum	Status {   I2C_OK = 0, I2C_SCL_HELD_LOW = 1, I2C_SCL_HELD_LOW_AFTER_READ = 2, I2C_SDA_HELD_LOW = 3,   I2C_SDA_HELD_LOW_AFTER_INIT = 4 }
enum	Error { I2C_ERR_SUCCESS = 0, I2C_ERR_ADDR_NACK = 2, I2C_ERR_DATA_NACK = 3, I2C_ERR_LINE_BUSY = 4 }
using	UserRequest = void(*)()
using	UserReceive = void(*)(int len)

Public Member Functions
	TwoWire ()
void	begin (uint8_t sda, uint8_t scl)
	Initialise using selected pins. More...
void	pins (uint8_t sda, uint8_t scl)
	Switch to selected pins. More...
void	begin ()
	Initialise using current pin values. More...
void	end ()
	End TwoWire operation. More...
void	setClock (uint32_t frequency)
	Set approximate clock frequency. More...
void	setClockStretchLimit (uint32_t limit)
	Set approximate time in microseconds that clocks may be stretched by. More...
void	beginTransmission (uint8_t address)
	Signal start of transaction. More...
Error	endTransmission (bool sendStop=true)
	Perform actual transaction with device. More...
uint8_t	requestFrom (uint8_t address, uint8_t size, bool sendStop=true)
	Perform a complete 'read' transaction. More...
Status	status ()
	Query bus status. More...
size_t	write (uint8_t) override
	Writes a single character to output stream. More...
size_t	write (const uint8_t *, size_t) override
	Writes characters from a buffer to output stream. More...
int	available () override
int	read () override
int	peek () override
void	flush () override
void	onReceive (UserReceive callback)
void	onRequest (UserRequest callback)
virtual size_t	write (uint8_t c)=0
	Writes a single character to output stream. More...
size_t	write (const char *str)
	Writes a c-string to output stream. More...
virtual size_t	write (const uint8_t *buffer, size_t size)
	Writes characters from a buffer to output stream. More...
size_t	write (const char *buffer, size_t size)
	Writes characters from a buffer to output stream. More...
Public Member Functions inherited from Stream
	Stream ()
void	setTimeout (unsigned long timeout)
	Set maximum milliseconds to wait for stream data, default is 1 second. More...
bool	find (const char *target)
	Read data from the stream until the target string is found. More...
bool	find (const char *target, size_t length)
	Read data from the stream until the target string of given length is found. More...
bool	findUntil (const char *target, const char *terminator)
	As find() but search ends if the terminator string is found. More...
bool	findUntil (const char *target, size_t targetLen, const char *terminate, size_t termLen)
	As findUntil(const char*, const char*) but search ends if the terminate string is found. More...
long	parseInt ()
	Returns the first valid (long) integer value from the current position. More...
float	parseFloat ()
	float version of parseInt More...
virtual size_t	readBytes (char *buffer, size_t length)
	Read chars from stream into buffer. More...
size_t	readBytes (uint8_t *buffer, size_t length)
size_t	readBytesUntil (char terminator, char *buffer, size_t length)
	As readBytes() with terminator character. More...
virtual String	readString (size_t maxLen)
	Like readBytes but place content into a String More...
String	readStringUntil (char terminator)
virtual int	indexOf (char c)
Public Member Functions inherited from Print
virtual	~Print ()
int	getWriteError ()
	Gets last error. More...
void	clearWriteError ()
	Clears the last write error. More...
size_t	write (const char *str)
	Writes a c-string to output stream. More...
size_t	write (const char *buffer, size_t size)
	Writes characters from a buffer to output stream. More...
size_t	print (char c)
	Prints a single character to output stream. More...
size_t	print (const char str[])
	Prints a c-string to output stream. More...
size_t	print (double num, int digits=2)
	Print a floating-point number to output stream. More...
template<typename T >
std::enable_if< has_printTo< T >::value, size_t >::type	print (const T &obj)
	Prints a Printable object to output stream. More...
size_t	print (const String &s)
	Prints a String to output stream. More...
template<typename E >
std::enable_if< std::is_enum< E >::value &&!std::is_convertible< E, int >::value, size_t >::type	print (E value)
	enums can be printed as strings provided they have a toString(E) implementation. More...
size_t	println ()
	Prints a newline to output stream. More...
template<typename... Args>
size_t	println (const Args &... args)
	Print value plus newline to output stream. More...
size_t	printf (const char *fmt,...)
	Prints a formatted c-string to output stream. More...
size_t	print (unsigned long num, uint8_t base=DEC)
template<typename... Args>
size_t	print (unsigned long num, Args... args)
template<typename... Args>
size_t	print (const unsigned long long &num, Args... args)
size_t	print (long num, uint8_t base=DEC)
template<typename... Args>
size_t	print (long num, Args... args)
template<typename... Args>
size_t	print (const long long &num, Args... args)
template<typename... Args>
size_t	print (unsigned int num, Args... args)
template<typename... Args>
size_t	print (unsigned char num, Args... args)
template<typename... Args>
size_t	print (int num, Args... args)

Static Public Attributes
static constexpr size_t	BUFFER_LENGTH {32}

Additional Inherited Members
Protected Member Functions inherited from Stream
int	timedRead ()
int	timedPeek ()
int	peekNextDigit ()
	returns the next numeric digit in the stream or -1 if timeout More...
long	parseInt (char skipChar)
	Like regular parseInt() but the given skipChar is ignored. More...
float	parseFloat (char skipChar)
	Like parseInt(skipChar) for float. More...
Protected Member Functions inherited from Print
void	setWriteError (int err=1)
Protected Attributes inherited from Stream
uint16_t	receiveTimeout = 1000
	number of milliseconds to wait for the next char before aborting timed read More...

Member Typedef Documentation

UserReceive

using TwoWire::UserReceive = void (*)(int len)

UserRequest

using TwoWire::UserRequest = void (*)()

Member Enumeration Documentation

Error

enum TwoWire::Error

Enumerator
I2C_ERR_SUCCESS
I2C_ERR_ADDR_NACK
I2C_ERR_DATA_NACK
I2C_ERR_LINE_BUSY

Status

enum TwoWire::Status

Enumerator
I2C_OK
I2C_SCL_HELD_LOW
I2C_SCL_HELD_LOW_AFTER_READ
I2C_SDA_HELD_LOW
I2C_SDA_HELD_LOW_AFTER_INIT

Constructor & Destructor Documentation

TwoWire()

TwoWire::TwoWire ( )

inline

Member Function Documentation

available()

int TwoWire::available ( )

overridevirtual

Implements Stream.

begin() [1/2]

void TwoWire::begin

(

)

Initialise using current pin values.

Default pins depend on selected architecture.

begin() [2/2]

void TwoWire::begin	(	uint8_t	sda,
		uint8_t	scl
	)

Initialise using selected pins.

beginTransmission()

void TwoWire::beginTransmission

(

uint8_t

address

)

Signal start of transaction.

Parameters

address

Device address

end()

void TwoWire::end

(

)

End TwoWire operation.

endTransmission()

Error TwoWire::endTransmission

(

bool

sendStop = true

)

Perform actual transaction with device.

Parameters

sendStop

By default, send a stop condition

flush()

void TwoWire::flush ( )

overridevirtual

Implements Stream.

onReceive()

void TwoWire::onReceive ( UserReceive  callback )

inline

onRequest()

void TwoWire::onRequest ( UserRequest  callback )

inline

peek()

int TwoWire::peek ( )

overridevirtual

Implements Stream.

pins()

void TwoWire::pins	(	uint8_t	sda,
		uint8_t	scl
	)

Switch to selected pins.

If begin() has already been called then pins will change immediately, otherwise will be used by next call to begin().

read()

int TwoWire::read ( )

overridevirtual

Implements Stream.

requestFrom()

uint8_t TwoWire::requestFrom	(	uint8_t	address,
		uint8_t	size,
		bool	sendStop = true
	)

Perform a complete 'read' transaction.

Parameters

address	Device to talk to
size	Number of bytes to receive
sendStop	By default, send a stop condition

setClock()

void TwoWire::setClock

(

uint32_t

frequency

)

Set approximate clock frequency.

setClockStretchLimit()

void TwoWire::setClockStretchLimit

(

uint32_t

limit

)

Set approximate time in microseconds that clocks may be stretched by.

status()

Status TwoWire::status

(

)

Query bus status.

Return values

Status

Indicates whether bus is available

write() [1/6]

size_t Print::write

inline

Writes characters from a buffer to output stream.

Parameters

buffer	Pointer to character buffer
size	Quantity of characters to write

Return values

size_t

Quantity of characters written to stream

write() [2/6]

size_t Print::write

inline

Writes a c-string to output stream.

Parameters

str	Pointer to c-string

Return values

size_t

Quantity of characters written to stream

write() [3/6]

size_t TwoWire::write ( const uint8_t *  buffer, size_t  size  )

overridevirtual

Writes characters from a buffer to output stream.

Parameters

buffer	Pointer to character buffer
size	Quantity of characters to write

Return values

size_t

Quantity of characters written to stream

Reimplemented from Print.

write() [4/6]

virtual size_t Print::write

Writes characters from a buffer to output stream.

Parameters

buffer	Pointer to character buffer
size	Quantity of characters to write

Return values

size_t

Quantity of characters written to stream

write() [5/6]

virtual size_t Print::write

Writes a single character to output stream.

Parameters

c	Character to write to output stream

Return values

size_t

Quantity of characters written to output stream

write() [6/6]

size_t TwoWire::write ( uint8_t  c )

overridevirtual

Writes a single character to output stream.

Parameters

c	Character to write to output stream

Return values

size_t

Quantity of characters written to output stream

Implements Print.

Member Data Documentation

BUFFER_LENGTH

constexpr size_t TwoWire::BUFFER_LENGTH {32}

staticconstexpr

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

• Wire.h