#include <modm/architecture/interface/i2c_transaction.hpp>

Inheritance diagram for modm::I2cWriteReadTransaction:

Public Typedefs
using	ConfigurationHandler = void (*)()
	The signature of the configuration function.

Public Types
enum	DetachCause : uint8_t { DetachCause::NormalStop, DetachCause::ErrorCondition, DetachCause::FailedToAttach }

enum	TransactionState : uint8_t { TransactionState::Idle, TransactionState::Busy, TransactionState::Error }
	State of a I2c Transaction. More...


enum	Operation : uint8_t { Operation::Stop = 0, Operation::Restart = 1, Operation::Write = 2, Operation::Read = 3 }
	All possible I2C Operations. More...

enum	OperationAfterRead : uint8_t { OperationAfterRead::Stop = uint8_t(Operation::Stop), OperationAfterRead::Restart = uint8_t(Operation::Restart) }
	Further operations after read operation. More...

enum	OperationAfterStart : uint8_t { OperationAfterStart::Stop = uint8_t(Operation::Stop), OperationAfterStart::Write = uint8_t(Operation::Write), OperationAfterStart::Read = uint8_t(Operation::Read) }
	Further operations after start operation. More...

enum	OperationAfterWrite : uint8_t { OperationAfterWrite::Stop = uint8_t(Operation::Stop), OperationAfterWrite::Restart = uint8_t(Operation::Restart), OperationAfterWrite::Write = uint8_t(Operation::Write) }
	Further operations after write operation. More...

Public Member Functions
	I2cWriteReadTransaction (uint8_t address)

bool	configurePing ()

bool	configureWriteRead (const uint8_t writeBuffer, std::size_t writeSize, uint8_t readBuffer, std::size_t readSize)

bool	configureWrite (const uint8_t *buffer, std::size_t size)

bool	configureRead (uint8_t *buffer, std::size_t size)

virtual bool	attaching ()

bool	configureWrite (uint8_t *buffer, std::size_t size)

virtual void	detaching (DetachCause cause)

TransactionState	getState () const

bool	isBusy () const

void	setAddress (uint8_t address)

Static Public Member Functions
template<class Scl >
static void	resetDevices (uint32_t baudrate=100'000)

Static Public Attributes
static constexpr uint8_t	Read = 0x01
	Add the Read bit to the slave address.

static constexpr uint8_t	Write = 0x00
	Add the Write bit to the slave address.

Protected Member Functions
Starting	starting () override

Writing	writing () override

Reading	reading () override

Protected Attributes
std::size_t	readSize

std::size_t	writeSize

uint8_t *	readBuffer

const uint8_t *	writeBuffer

bool	isReading

uint8_t	address

volatile TransactionState	state

Detailed Description

This class is an implementation of modm::I2cTransaction which, when passed to an i2c driver, performs the sequence: start - address - write - restart - address - read - stop.

After initialization and performing operation this class keeps the references to passed buffers and may be reused again without reinitialization as long the passed buffers remain valid.

Author: Georgi Grinshpun; Niklas Hauser

Member Enumeration Documentation

enum modm::I2c::DetachCause : uint8_t

inheritedstrong

This tells the I2cTransaction why it was detached

See also: I2cTransaction

Enum Values	Documentation
NormalStop	All operations finished normally.
ErrorCondition	A bus error occurred and the bus was reset.
FailedToAttach	The I2cTransaction failed to attach to the I2cMaster.

enum modm::I2c::Operation : uint8_t

inheritedstrong

All possible I2C Operations.

I2C Operations that the I2cTransaction can give the master on callback

See also: I2cTransaction

Enum Values	Documentation
Stop	Generate a Stop Condition.
Restart	Generate a Restart.
Write	Write data to the slave.
Read	Read data from the slave.

enum modm::I2c::OperationAfterRead : uint8_t

inheritedstrong

Further operations after read operation.

Enum Values	Documentation
Stop	Generate a Stop Condition.
Restart	Generate a Restart.

enum modm::I2c::OperationAfterStart : uint8_t

inheritedstrong

Further operations after start operation.

Enum Values	Documentation
Stop	Generate a Stop Condition.
Write	Write data to the slave.
Read	Read data from the slave.

enum modm::I2c::OperationAfterWrite : uint8_t

inheritedstrong

Further operations after write operation.

Enum Values	Documentation
Stop	Generate a Stop Condition.
Restart	Generate a Restart.
Write	Write data to the slave.

enum modm::I2c::TransactionState : uint8_t

inheritedstrong

State of a I2c Transaction.

Enum Values	Documentation
Idle	No error occurred, detached normally.
Busy	The transaction object is busy with data transfer.
Error	An error occurred, check the masters `getErrorCode()`

Member Function Documentation

virtual bool modm::I2cTransaction::attaching ( )

inheritedinlinevirtual

This method is called when the I2cMaster is not currently in use by another transaction and can be attached.

Returns: true if the I2cMaster should attach this transaction, false if it should not attach it.

bool modm::I2cWriteReadTransaction::configureRead	(	uint8_t *	buffer,
		std::size_t	size
	)

inline

Initializes the adapter with the required information for a read operation.

Parameters

[out]	buffer	buffer to be read from the slave
	size	number of bytes to be read, set to `0` to read nothing

Returns: true if adapter was not in use, false otherwise

bool modm::I2cWriteReadTransaction::configureWrite	(	const uint8_t *	buffer,
		std::size_t	size
	)

inline

Initializes the adapter with the required information for a write operation.

Parameters

[in]	buffer	buffer to be written to the slave
	size	number of bytes to be written, set to `0` to write nothing

Returns: true if adapter was not in use, false otherwise

bool modm::I2cTransaction::configureWrite	(	uint8_t *	buffer,
		std::size_t	size
	)

inherited

Initializes the adapter with the required information for a write operation.

Parameters

[in]	buffer	buffer to be written to the slave
	size	number of bytes to be written, set to `0` to write nothing

Return Values

<code>true</code>	adapter configured successfully,
<code>false</code>	adapter busy

virtual void modm::I2cTransaction::detaching ( DetachCause cause )

inheritedinlinevirtual

This is called when all transmissions finished and transaction object is about to be detached. The I2cMaster will not be free until this method returns.

Parameters

cause specifies whether the detachment was expected (NormalStop), or a error occurred (ErrorCondition), which can, but does not need to be reacted upon.

TransactionState modm::I2cTransaction::getState ( ) const

inheritedinline

Returns: Busy while an I2C operation is ongoing. Reinitialization is not permitted during this phase.

bool modm::I2cTransaction::isBusy ( ) const

inheritedinline

Returns: true while adapter is busy

Reading modm::I2cWriteReadTransaction::reading ( )

inlineoverrideprotectedvirtual

This method is called before the I2cMaster begins a read operation.

Returns: the Reading struct containing the read buffer and size and next operation

Implements modm::I2cTransaction.

template<class Scl >

static void modm::I2c::resetDevices ( uint32_t baudrate = 100'000 )

inheritedinlinestatic

Reset all slave devices connected to an I2C bus.

During normal operation, I2C slave device may pull the SDA line low. However, if the master is reset during a transaction, the I2C clock may stop while the slave is outputting a low data bit and the slave will continue to hold this bit (forever, and ever and ever). The I2C master is then unable to generate a I2C start condition, since SDA is still held low by the slave device, resulting in a deadlock.

"You can always get it back to standby mode by allowing the SDA line to float high and give it 9 clocks. This assures that the device will not receive the acknowledge bit at the end the current byte and will abort the command and go to standby."

See also: Application Note AN572 by Microchip

Warning: Must be called before connecting SDA and SCL to I2cMaster!

Template Parameters

Scl	The clock pin of the bus to be reset.

void modm::I2cTransaction::setAddress ( uint8_t address )

inheritedinline

Parameters

address the slave address not yet shifted left (address < 128).

Starting modm::I2cWriteReadTransaction::starting ( )

inlineoverrideprotectedvirtual

This method is called when the I2cMaster is ready to (re-)start an operation.

Returns: the Starting struct containing slave address and the next operation

Implements modm::I2cTransaction.

Writing modm::I2cWriteReadTransaction::writing ( )

inlineoverrideprotectedvirtual

This method is called before the I2cMaster begins a write operation.

Returns: the Writing struct containing the write buffer and size and next operation

Implements modm::I2cTransaction.

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

i2c_transaction.hpp

Public Typedefs

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Member Function Documentation