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

Inheritance diagram for modm::I2cTransaction:

Classes
struct	Reading

struct	Starting

struct	Writing

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
	I2cTransaction (uint8_t address)

void	setAddress (uint8_t address)

TransactionState	getState () const

bool	isBusy () const

bool	configurePing ()

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

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

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

virtual bool	attaching ()

virtual Starting	starting () = 0

virtual Writing	writing () = 0

virtual Reading	reading () = 0

virtual void	detaching (DetachCause cause)

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 Attributes
uint8_t	address

volatile TransactionState	state

Detailed Description

Abstract class for transactions.

For true asynchronous operation, the communication driver should inherit from this class, allowing multi-stage driver design and performance gain by premature data evaluation. This transaction object will stay attached to the I2cMaster during whole operation.

See also: I2cMaster

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()`

Constructor & Destructor Documentation

modm::I2cTransaction::I2cTransaction ( uint8_t address )

inline

Parameters

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

Member Function Documentation

virtual bool modm::I2cTransaction::attaching ( )

inlinevirtual

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::I2cTransaction::configurePing ( )

Initializes the adapter to only send the address without payload.

Return Values

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

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

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

Return Values

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

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

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

bool modm::I2cTransaction::configureWriteRead	(	const uint8_t *	writeBuffer,
		std::size_t	writeSize,
		uint8_t *	readBuffer,
		std::size_t	readSize
	)

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

Parameters

[in]	writeBuffer	buffer to be written to the slave
	writeSize	number of bytes to be written, set to `0` to write nothing
[out]	readBuffer	buffer to write the read bytes from the slave
	readSize	number of bytes to be read, set to `0` to read nothing

Return Values

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

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

inlinevirtual

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

inline

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

bool modm::I2cTransaction::isBusy ( ) const

inline

Returns: true while adapter is busy

virtual Reading modm::I2cTransaction::reading ( )

pure virtual

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

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

Implemented in modm::I2cReadTransaction, modm::I2cWriteTransaction, and modm::I2cWriteReadTransaction.

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 )

inline

Parameters

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

virtual Starting modm::I2cTransaction::starting ( )

pure virtual

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

Implemented in modm::I2cReadTransaction, modm::I2cWriteTransaction, and modm::I2cWriteReadTransaction.

virtual Writing modm::I2cTransaction::writing ( )

pure virtual

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

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

Implemented in modm::I2cReadTransaction, modm::I2cWriteTransaction, and modm::I2cWriteReadTransaction.

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

i2c_transaction.hpp

Classes

Public Typedefs

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation