This Class provides the methods to read and write bytes from an I2CBus. More...

#include <i2c_bus.h>

Inheritance diagram for esphome::i2c::I2CBus:

Public Member Functions
virtual ErrorCode	read (uint8_t address, uint8_t *buffer, size_t len)
	Creates a ReadBuffer and calls the virtual readv() method to read bytes into this buffer. More...

virtual ErrorCode	readv (uint8_t address, ReadBuffer *buffers, size_t count)=0
	This virtual method reads bytes from an I2CBus into an array of ReadBuffer. More...

virtual ErrorCode	write (uint8_t address, const uint8_t *buffer, size_t len)

virtual ErrorCode	write (uint8_t address, const uint8_t *buffer, size_t len, bool stop)
	Creates a WriteBuffer and calls the writev() method to send the bytes from this buffer. More...

virtual ErrorCode	writev (uint8_t address, WriteBuffer *buffers, size_t cnt)

virtual ErrorCode	writev (uint8_t address, WriteBuffer *buffers, size_t count, bool stop)=0
	This virtual method writes bytes to an I2CBus from an array of WriteBuffer. More...

Protected Member Functions
void	i2c_scan_ ()
	Scans the I2C bus for devices. More...

Protected Attributes
std::vector< std::pair< uint8_t, bool > >	scan_results_
	array containing scan results More...

bool	scan_ {false}
	Should we scan ? Can be set in the yaml. More...

Detailed Description

This Class provides the methods to read and write bytes from an I2CBus.

Note: The I2CBus virtual class follows a Factory design pattern that provides all the interfaces methods required by clients while deferring the actual implementation of these methods to a subclasses. I2C-bus specification and user manual can be found here https://www.nxp.com/docs/en/user-guide/UM10204.pdf and an interesting I²C Application note https://www.nxp.com/docs/en/application-note/AN10216.pdf

Definition at line 40 of file i2c_bus.h.

Member Function Documentation

◆ i2c_scan_()

void esphome::i2c::I2CBus::i2c_scan_ ( )

inlineprotected

Scans the I2C bus for devices.

Devices presence is kept in an array of std::pair that contains the address and the corresponding bool presence flag.

Definition at line 97 of file i2c_bus.h.

◆ read()

virtual ErrorCode esphome::i2c::I2CBus::read	(	uint8_t	address,
		uint8_t *	buffer,
		size_t	len
	)

inlinevirtual

Creates a ReadBuffer and calls the virtual readv() method to read bytes into this buffer.

Parameters

address	address of the I²C component on the i2c bus
buffer	pointer to an array of bytes that will be used to store the data received
len	length of the buffer = number of bytes to read

Returns: an i2c::ErrorCode

Definition at line 47 of file i2c_bus.h.

◆ readv()

virtual ErrorCode esphome::i2c::I2CBus::readv	(	uint8_t	address,
		ReadBuffer *	buffers,
		size_t	count
	)

pure virtual

This virtual method reads bytes from an I2CBus into an array of ReadBuffer.

Parameters

address	address of the I²C component on the i2c bus
buffers	pointer to an array of ReadBuffer
count	number of ReadBuffer to read

Returns: an i2c::ErrorCode

This is a pure virtual method that must be implemented in a subclass.

Implemented in esphome::i2c::ArduinoI2CBus, esphome::i2c::IDFI2CBus, and esphome::tca9548a::TCA9548AChannel.

◆ write() [1/2]

virtual ErrorCode esphome::i2c::I2CBus::write	(	uint8_t	address,
		const uint8_t *	buffer,
		size_t	len
	)

inlinevirtual

Definition at line 62 of file i2c_bus.h.

◆ write() [2/2]

virtual ErrorCode esphome::i2c::I2CBus::write	(	uint8_t	address,
		const uint8_t *	buffer,
		size_t	len,
		bool	stop
	)

inlinevirtual

Creates a WriteBuffer and calls the writev() method to send the bytes from this buffer.

Parameters

address	address of the I²C component on the i2c bus
buffer	pointer to an array of bytes that contains the data to be sent
len	length of the buffer = number of bytes to write
stop	true or false: True will send a stop message, releasing the bus after transmission. False will send a restart, keeping the connection active.

Returns: an i2c::ErrorCode

Definition at line 73 of file i2c_bus.h.

◆ writev() [1/2]

virtual ErrorCode esphome::i2c::I2CBus::writev	(	uint8_t	address,
		WriteBuffer *	buffers,
		size_t	cnt
	)

inlinevirtual

Definition at line 80 of file i2c_bus.h.

◆ writev() [2/2]

virtual ErrorCode esphome::i2c::I2CBus::writev	(	uint8_t	address,
		WriteBuffer *	buffers,
		size_t	count,
		bool	stop
	)

pure virtual

This virtual method writes bytes to an I2CBus from an array of WriteBuffer.

Parameters

address	address of the I²C component on the i2c bus
buffers	pointer to an array of WriteBuffer
count	number of WriteBuffer to write
stop	true or false: True will send a stop message, releasing the bus after transmission. False will send a restart, keeping the connection active.

Returns: an i2c::ErrorCode

This is a pure virtual method that must be implemented in the subclass.

Implemented in esphome::i2c::ArduinoI2CBus, esphome::i2c::IDFI2CBus, and esphome::tca9548a::TCA9548AChannel.

Field Documentation

◆ scan_

bool esphome::i2c::I2CBus::scan_ {false}

protected

Should we scan ? Can be set in the yaml.

Definition at line 108 of file i2c_bus.h.

◆ scan_results_

std::vector<std::pair<uint8_t, bool> > esphome::i2c::I2CBus::scan_results_

protected

array containing scan results

Definition at line 107 of file i2c_bus.h.

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

/opt/build/esphome/esphome/components/i2c/i2c_bus.h

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ i2c_scan_()

◆ read()

◆ readv()

◆ write() [1/2]

◆ write() [2/2]

◆ writev() [1/2]

◆ writev() [2/2]

Field Documentation

◆ scan_

◆ scan_results_