#include <I2C.h>

Inheritance diagram for mbed::I2C:

Public Types
enum	RxStatus { NoData, MasterGeneralCall, MasterWrite, MasterRead }

enum	Acknowledge { NoACK = 0, ACK = 1 }

Public Member Functions
	I2C (PinName sda, PinName scl)

void	frequency (int hz)

int	read (int address, char *data, int length, bool repeated=false)

int	read (int ack)

int	write (int address, const char *data, int length, bool repeated=false)

int	write (int data)

void	start (void)

void	stop (void)

virtual void	lock (void)

virtual void	unlock (void)

int	transfer (int address, const char tx_buffer, int tx_length, char rx_buffer, int rx_length, const event_callback_t &callback, int event=I2C_EVENT_TRANSFER_COMPLETE, bool repeated=false)

void	abort_transfer ()

Protected Member Functions
void	lock_deep_sleep ()

void	unlock_deep_sleep ()

void	irq_handler_asynch (void)

void	aquire ()

Protected Attributes
event_callback_t	_callback

CThunk< I2C >	_irq

DMAUsage	_usage

bool	_deep_sleep_locked

i2c_t	_i2c

int	_hz

Static Protected Attributes
static I2C *	_owner = NULL

static SingletonPtr< PlatformMutex >	_mutex

Detailed Description

An I2C Master, used for communicating with I2C slave devices

Note: Synchronization level: Thread safe

Example:

// Read from I2C slave at address 0x62
#include "mbed.h"
I2C i2c(p28, p27);
int main() {
    int address = 0x62;
    char data[2];
    i2c.read(address, data, 2);
}

Constructor & Destructor Documentation

mbed::I2C::I2C	(	PinName	sda,
		PinName	scl
	)

Create an I2C Master interface, connected to the specified pins

Parameters

sda	I2C data line pin
scl	I2C clock line pin

Member Function Documentation

void mbed::I2C::abort_transfer ( void )

Abort the on-going I2C transfer

void mbed::I2C::frequency ( int hz )

Set the frequency of the I2C interface

Parameters

hz	The bus frequency in hertz

void mbed::I2C::lock ( void )

virtual

Acquire exclusive access to this I2C bus

void mbed::I2C::lock_deep_sleep ( )

protected

Lock deep sleep only if it is not yet locked

int mbed::I2C::read	(	int	address,
		char *	data,
		int	length,
		bool	repeated = `false`
	)

Read from an I2C slave

Performs a complete read transaction. The bottom bit of the address is forced to 1 to indicate a read.

Parameters

address	8-bit I2C slave address [ addr \| 1 ]
data	Pointer to the byte-array to read data in to
length	Number of bytes to read
repeated	Repeated start, true - don't send stop at end

Returns: 0 on success (ack), non-0 on failure (nack)

int mbed::I2C::read ( int ack )

Read a single byte from the I2C bus

Parameters

ack	indicates if the byte is to be acknowledged (1 = acknowledge)

Returns: the byte read

void mbed::I2C::start ( void )

Creates a start condition on the I2C bus

void mbed::I2C::stop ( void )

Creates a stop condition on the I2C bus

int mbed::I2C::transfer	(	int	address,
		const char *	tx_buffer,
		int	tx_length,
		char *	rx_buffer,
		int	rx_length,
		const event_callback_t &	callback,
		int	event = `I2C_EVENT_TRANSFER_COMPLETE`,
		bool	repeated = `false`
	)

Start non-blocking I2C transfer.

This function locks the deep sleep until any event has occurred

Parameters

address	8/10 bit I2C slave address
tx_buffer	The TX buffer with data to be transfered
tx_length	The length of TX buffer in bytes
rx_buffer	The RX buffer which is used for received data
rx_length	The length of RX buffer in bytes
event	The logical OR of events to modify
callback	The event callback function
repeated	Repeated start, true - do not send stop at end

Returns: Zero if the transfer has started, or -1 if I2C peripheral is busy

void mbed::I2C::unlock ( void )

virtual

Release exclusive access to this I2C bus

void mbed::I2C::unlock_deep_sleep ( )

protected

Unlock deep sleep only if it has been locked

int mbed::I2C::write	(	int	address,
		const char *	data,
		int	length,
		bool	repeated = `false`
	)

Write to an I2C slave

Performs a complete write transaction. The bottom bit of the address is forced to 0 to indicate a write.

Parameters

address	8-bit I2C slave address [ addr \| 0 ]
data	Pointer to the byte-array data to send
length	Number of bytes to send
repeated	Repeated start, true - do not send stop at end

Returns: 0 on success (ack), non-0 on failure (nack)

int mbed::I2C::write ( int data )

Write single byte out on the I2C bus

Parameters

data	data to write out on bus

Returns: '0' - NAK was received '1' - ACK was received, '2' - timeout

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

mbed-os/drivers/I2C.h
mbed-os/drivers/I2C.cpp

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Important Information for this Arm website