Adafruit_I2CDevice Class Reference

< The class which defines how we will talk to this device over I2C More...

#include <Adafruit_I2CDevice.h>

Public Member Functions
	Adafruit_I2CDevice (uint8_t addr, TwoWire *theWire=&Wire)
	Create an I2C device at a given address. More...
uint8_t	address (void)
	Returns the 7-bit address of this device. More...
bool	begin (bool addr_detect=true)
	Initializes and does basic address detection. More...
void	end (void)
	De-initialize device, turn off the Wire interface.
bool	detected (void)
	Scans I2C for the address - note will give a false-positive if there's no pullups on I2C. More...
bool	read (uint8_t *buffer, size_t len, bool stop=true)
	Read from I2C into a buffer from the I2C device. Cannot be more than maxBufferSize() bytes. More...
bool	write (const uint8_t *buffer, size_t len, bool stop=true, const uint8_t *prefix_buffer=nullptr, size_t prefix_len=0)
	Write a buffer or two to the I2C device. Cannot be more than maxBufferSize() bytes. More...
bool	write_then_read (const uint8_t *write_buffer, size_t write_len, uint8_t *read_buffer, size_t read_len, bool stop=false)
	Write some data, then read some data from I2C into another buffer. Cannot be more than maxBufferSize() bytes. The buffers can point to same/overlapping locations. More...
bool	setSpeed (uint32_t desiredclk)
	Change the I2C clock speed to desired (relies on underlying Wire support! More...
size_t	maxBufferSize ()
	How many bytes we can read in a transaction. More...

Detailed Description

< The class which defines how we will talk to this device over I2C

Constructor & Destructor Documentation

Adafruit_I2CDevice()

Adafruit_I2CDevice::Adafruit_I2CDevice	(	uint8_t	addr,
		TwoWire *	theWire = &Wire
	)

Create an I2C device at a given address.

Parameters

addr	The 7-bit I2C address for the device
theWire	The I2C bus to use, defaults to &Wire

Member Function Documentation

address()

uint8_t Adafruit_I2CDevice::address

(

void

)

Returns the 7-bit address of this device.

Returns

The 7-bit address of this device

begin()

bool Adafruit_I2CDevice::begin

(

bool

addr_detect = true

)

Initializes and does basic address detection.

Parameters

addr_detect

Whether we should attempt to detect the I2C address with a scan. 99% of sensors/devices don't mind, but once in a while they don't respond well to a scan!

Returns

True if I2C initialized and a device with the addr found

detected()

bool Adafruit_I2CDevice::detected

(

void

)

Scans I2C for the address - note will give a false-positive if there's no pullups on I2C.

Returns

True if I2C initialized and a device with the addr found

read()

bool Adafruit_I2CDevice::read	(	uint8_t *	buffer,
		size_t	len,
		bool	stop = true
	)

Read from I2C into a buffer from the I2C device. Cannot be more than maxBufferSize() bytes.

Parameters

buffer	Pointer to buffer of data to read into
len	Number of bytes from buffer to read.
stop	Whether to send an I2C STOP signal on read

Returns

True if read was successful, otherwise false.

write()

bool Adafruit_I2CDevice::write	(	const uint8_t *	buffer,
		size_t	len,
		bool	stop = true,
		const uint8_t *	prefix_buffer = nullptr,
		size_t	prefix_len = 0
	)

Write a buffer or two to the I2C device. Cannot be more than maxBufferSize() bytes.

Parameters

buffer	Pointer to buffer of data to write. This is const to ensure the content of this buffer doesn't change.
len	Number of bytes from buffer to write
prefix_buffer	Pointer to optional array of data to write before buffer. Cannot be more than maxBufferSize() bytes. This is const to ensure the content of this buffer doesn't change.
prefix_len	Number of bytes from prefix buffer to write
stop	Whether to send an I2C STOP signal on write

Returns

True if write was successful, otherwise false.

write_then_read()

bool Adafruit_I2CDevice::write_then_read	(	const uint8_t *	write_buffer,
		size_t	write_len,
		uint8_t *	read_buffer,
		size_t	read_len,
		bool	stop = false
	)

Write some data, then read some data from I2C into another buffer. Cannot be more than maxBufferSize() bytes. The buffers can point to same/overlapping locations.

Parameters

write_buffer	Pointer to buffer of data to write from
write_len	Number of bytes from buffer to write.
read_buffer	Pointer to buffer of data to read into.
read_len	Number of bytes from buffer to read.
stop	Whether to send an I2C STOP signal between the write and read

Returns

True if write & read was successful, otherwise false.

setSpeed()

bool Adafruit_I2CDevice::setSpeed

(

uint32_t

desiredclk

)

Change the I2C clock speed to desired (relies on underlying Wire support!

Parameters

desiredclk

The desired I2C SCL frequency

Returns

True if this platform supports changing I2C speed. Not necessarily that the speed was achieved!

maxBufferSize()

size_t Adafruit_I2CDevice::maxBufferSize ( )

inline

How many bytes we can read in a transaction.

Returns

The size of the Wire receive/transmit buffer

---

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

• Adafruit_I2CDevice.h
• Adafruit_I2CDevice.cpp