Detailed Description

A handle for interacting with an I2C peripheral. This is a dumb gateway that internally points to one of the four I2C peripherals after it was initialised. It can then be copied and passed around. Use an I2CHandle like this:

// setup the configuration
I2CHandle::Config i2c_conf;
i2c_conf.periph = I2CHandle::Config::Peripheral::I2C_1;
i2c_conf.speed  = I2CHandle::Config::Speed::I2C_400KHZ;
i2c_conf.mode   = I2CHandle::Config::Mode::Master;
i2c_conf.pin_config.scl  = {DSY_GPIOB, 8};
i2c_conf.pin_config.sda  = {DSY_GPIOB, 9};
// initialise the peripheral
I2CHandle i2c;
i2c.Init(i2c_conf);
// now i2c points to the corresponding peripheral and can be used.
i2c.TransmitBlocking( ... );

#include <i2c.h>

Classes
struct	Config

Public Types
enum class	Result { OK , ERR }

enum class	Direction { TRANSMIT , RECEIVE }

typedef void(*	CallbackFunctionPtr) (void *context, Result result)

Public Member Functions
	I2CHandle ()

	I2CHandle (const I2CHandle &other)=default

I2CHandle &	operator= (const I2CHandle &other)=default

Result	Init (const Config &config)

const Config &	GetConfig () const

Result	TransmitBlocking (uint16_t address, uint8_t *data, uint16_t size, uint32_t timeout)

Result	ReceiveBlocking (uint16_t address, uint8_t *data, uint16_t size, uint32_t timeout)

Result	TransmitDma (uint16_t address, uint8_t data, uint16_t size, CallbackFunctionPtr callback, void callback_context)

Result	ReceiveDma (uint16_t address, uint8_t data, uint16_t size, CallbackFunctionPtr callback, void callback_context)

Result	ReadDataAtAddress (uint16_t address, uint16_t mem_address, uint16_t mem_address_size, uint8_t *data, uint16_t data_size, uint32_t timeout)

Result	WriteDataAtAddress (uint16_t address, uint16_t mem_address, uint16_t mem_address_size, uint8_t *data, uint16_t data_size, uint32_t timeout)

Member Typedef Documentation

◆ CallbackFunctionPtr

typedef void(* daisy::I2CHandle::CallbackFunctionPtr) (void *context, Result result)

A callback to be executed when a dma transfer is complete.

Member Enumeration Documentation

◆ Direction

enum class daisy::I2CHandle::Direction

strong

Enumerator
TRANSMIT	&
RECEIVE	&

◆ Result

enum class daisy::I2CHandle::Result

strong

Return values for I2C functions.

Enumerator
OK	&
ERR	&

Constructor & Destructor Documentation

◆ I2CHandle() [1/2]

daisy::I2CHandle::I2CHandle ( )

inline

◆ I2CHandle() [2/2]

daisy::I2CHandle::I2CHandle ( const I2CHandle & other )

default

Member Function Documentation

◆ GetConfig()

const Config & daisy::I2CHandle::GetConfig ( ) const

Returns the current config.

◆ Init()

Result daisy::I2CHandle::Init ( const Config & config )

Initializes an I2C peripheral.

◆ operator=()

I2CHandle & daisy::I2CHandle::operator= ( const I2CHandle & other )

default

◆ ReadDataAtAddress()

Result daisy::I2CHandle::ReadDataAtAddress	(	uint16_t	address,
		uint16_t	mem_address,
		uint16_t	mem_address_size,
		uint8_t *	data,
		uint16_t	data_size,
		uint32_t	timeout
	)

Reads an amount of data from a specific memory address. This method will return an error if the I2C peripheral is in slave mode.

Parameters

address	The slave device address.
mem_address	Pointer to data containing the address to read from device.
mem_address_size	Size of the memory address in bytes.
data	Pointer to buffer that will be filled with contents at mem_address
data_size	Size of the data to be read in bytes.
timeout	The timeout in milliseconds before returning without communication

◆ ReceiveBlocking()

Result daisy::I2CHandle::ReceiveBlocking	(	uint16_t	address,
		uint8_t *	data,
		uint16_t	size,
		uint32_t	timeout
	)

Receives data and blocks until the reception is complete. Use this for smaller transmissions of a few bytes.

Parameters

address	The slave device address. Unused in slave mode.
data	A pointer to the data to be received.
size	The size of the data to be received, in bytes.
timeout	A timeout.

◆ ReceiveDma()

Result daisy::I2CHandle::ReceiveDma	(	uint16_t	address,
		uint8_t *	data,
		uint16_t	size,
		CallbackFunctionPtr	callback,
		void *	callback_context
	)

Receives data with a DMA and returns immediately. Use this for larger transmissions. The pointer to data must be located in the D2 memory domain by adding the DMA_BUFFER_MEM_SECTION attribute like this: uint8_t DMA_BUFFER_MEM_SECTION my_buffer[100]; If that is not possible for some reason, you MUST clear the cachelines spanning the size of the buffer, before initiating the dma transfer by calling dsy_dma_clear_cache_for_buffer(buffer, size);

A single DMA is shared across I2C, I2C2 and I2C3. I2C4 has no DMA support (yet). If the DMA is busy with another transfer, the job will be queued and executed later. If there is a job waiting to be executed for this I2C peripheral, this function will block until the queue is free and the job can be queued.

Parameters

address	The slave device address. Unused in slave mode.
data	A pointer to the data buffer.
size	The size of the data to be received, in bytes.
callback	A callback to execute when the transfer finishes, or NULL.
callback_context	A pointer that will be passed back to you in the callback.

◆ TransmitBlocking()

Result daisy::I2CHandle::TransmitBlocking	(	uint16_t	address,
		uint8_t *	data,
		uint16_t	size,
		uint32_t	timeout
	)

Transmits data and blocks until the transmission is complete. Use this for smaller transmissions of a few bytes.

Parameters

address	The slave device address. Unused in slave mode.
data	A pointer to the data to be sent.
size	The size of the data to be sent, in bytes.
timeout	A timeout.

◆ TransmitDma()

Result daisy::I2CHandle::TransmitDma	(	uint16_t	address,
		uint8_t *	data,
		uint16_t	size,
		CallbackFunctionPtr	callback,
		void *	callback_context
	)

Transmits data with a DMA and returns immediately. Use this for larger transmissions. The pointer to data must be located in the D2 memory domain by adding the DMA_BUFFER_MEM_SECTION attribute like this: uint8_t DMA_BUFFER_MEM_SECTION my_buffer[100]; If that is not possible for some reason, you MUST clear the cachelines spanning the size of the buffer, before initiating the dma transfer by calling dsy_dma_clear_cache_for_buffer(buffer, size);

A single DMA is shared across I2C1, I2C2 and I2C3. I2C4 has no DMA support (yet). If the DMA is busy with another transfer, the job will be queued and executed later. If there is a job waiting to be executed for this I2C peripheral, this function will block until the queue is free and the job can be queued.

Parameters

address	The slave device address. Unused in slave mode.
data	A pointer to the data to be sent.
size	The size of the data to be sent, in bytes.
callback	A callback to execute when the transfer finishes, or NULL.
callback_context	A pointer that will be passed back to you in the callback.

◆ WriteDataAtAddress()

Result daisy::I2CHandle::WriteDataAtAddress	(	uint16_t	address,
		uint16_t	mem_address,
		uint16_t	mem_address_size,
		uint8_t *	data,
		uint16_t	data_size,
		uint32_t	timeout
	)

Writes an amount of data from a specific memory address. This method will return an error if the I2C peripheral is in slave mode.

Parameters

address	The slave device address.
mem_address	Pointer to data containing the address to write to device.
mem_address_size	Size of the memory address in bytes.
data	Pointer to buffer that will be written to the mem_address
data_size	Size of the data to be written in bytes.
timeout	The timeout in milliseconds before returning without communication

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

src/per/i2c.h

Detailed Description

Classes

Public Types

Public Member Functions

Member Typedef Documentation

◆ CallbackFunctionPtr

Member Enumeration Documentation

◆ Direction

◆ Result

Constructor & Destructor Documentation

◆ I2CHandle() [1/2]

◆ I2CHandle() [2/2]

Member Function Documentation

◆ GetConfig()

◆ Init()

◆ operator=()

◆ ReadDataAtAddress()

◆ ReceiveBlocking()

◆ ReceiveDma()

◆ TransmitBlocking()

◆ TransmitDma()

◆ WriteDataAtAddress()