Summary: Methods | Inherited Methods | [Expand All]

I2cDevice

public interface I2cDevice
implements Closeable

com.google.android.things.pio.I2cDevice

---

Controls an I2C device. I2C is a bus protocol allowing a master (running Android headless) to control multiple slave device connected to this bus. Each device must have a unique address to disambiguate the commands sent. Some devices use the notion of register (also called commands), allowing you to select a memory address to read from/write to. The datasheet for your device will explain what each register is used for. Opening an I2C device takes ownership of it for the whole system, preventing anyone else from opening/accessing this device until you call close(). Forgetting to call close() will prevent anyone (including the same process/app) from using the device.

Summary

Public methods
abstract void	close() Close and release the device.
default String	getName() Returns the I/O name.
abstract void	read(byte[] buffer, int length) Read data from the device.
abstract void	readRegBuffer(int reg, byte[] buffer, int length) Read multiple bytes from a given register.
abstract byte	readRegByte(int reg) Read a byte from a given register.
abstract short	readRegWord(int reg) Read a 2-byte word from a given register.
abstract void	write(byte[] buffer, int length) Write data to the device.
abstract void	writeRegBuffer(int reg, byte[] buffer, int length) Write a byte array to a given register.
abstract void	writeRegByte(int reg, byte data) Write a byte to a given register.
abstract void	writeRegWord(int reg, short data) Write a 2-byte word to a given register.

Inherited methods
From interface java.io.Closeable abstract void close() Closes this stream and releases any system resources associated with it.
From interface java.lang.AutoCloseable abstract void close() Closes this resource, relinquishing any underlying resources.

Public methods

close

void close ()

Close and release the device. Must be called in order to make the device available to other users.

Throws
IOException	if the I2cDevice is already closed.

getName

String getName ()

Returns the I/O name.

Returns
String

read

void read (byte[] buffer, 
                int length)

Read data from the device.

Parameters
buffer	byte: Buffer to read data into.
length	int: Number of bytes to read, may not be larger than the buffer size.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• readRegByte(int)
• readRegWord(int)
• readRegBuffer(int, byte[], int)
• write(byte[], int)

readRegBuffer

void readRegBuffer (int reg, 
                byte[] buffer, 
                int length)

Read multiple bytes from a given register.

Parameters
reg	int: The register to read from (0x00-0xFF).
buffer	byte: Buffer to read data into.
length	int: Number of bytes to read, may not be larger than the buffer size.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• read(byte[], int)
• readRegByte(int)
• readRegWord(int)
• writeRegBuffer(int, byte[], int)

readRegByte

byte readRegByte (int reg)

Read a byte from a given register.

Parameters
reg	int: The register to read from (0x00-0xFF).

Returns
byte	The value read from the device.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• read(byte[], int)
• readRegWord(int)
• readRegBuffer(int, byte[], int)
• writeRegByte(int, byte)

readRegWord

short readRegWord (int reg)

Read a 2-byte word from a given register.

Parameters
reg	int: The register to read from (0x00-0xFF).

Returns
short	The 2-byte value read from the device.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• read(byte[], int)
• readRegByte(int)
• readRegBuffer(int, byte[], int)
• writeRegWord(int, short)

write

void write (byte[] buffer, 
                int length)

Write data to the device.

Parameters
buffer	byte: Data to write.
length	int: Number of bytes to write, may not be larger than the buffer size.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• read(byte[], int)
• writeRegByte(int, byte)
• writeRegWord(int, short)
• writeRegBuffer(int, byte[], int)

writeRegBuffer

void writeRegBuffer (int reg, 
                byte[] buffer, 
                int length)

Write a byte array to a given register.

Parameters
reg	int: The register to write to (0x00-0xFF).
buffer	byte: Data to write.
length	int: Number of bytes to write, may not be larger than the buffer size.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• readRegBuffer(int, byte[], int)
• write(byte[], int)
• writeRegByte(int, byte)
• writeRegWord(int, short)

writeRegByte

void writeRegByte (int reg, 
                byte data)

Write a byte to a given register.

Parameters
reg	int: The register to write to (0x00-0xFF).
data	byte: Value to write.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• readRegByte(int)
• write(byte[], int)
• writeRegWord(int, short)
• writeRegBuffer(int, byte[], int)

writeRegWord

void writeRegWord (int reg, 
                short data)

Write a 2-byte word to a given register.

Parameters
reg	int: The register to write to (0x00-0xFF).
data	short: Value to write.

Throws
	IOException
	IllegalArgumentException
IOException

See also:

• readRegWord(int)
• write(byte[], int)
• writeRegByte(int, byte)
• writeRegBuffer(int, byte[], int)

• Interfaces

  • Gpio
  • GpioCallback
  • I2cDevice
  • Pwm
  • SpiDevice
  • UartDevice
  • UartDeviceCallback

• Classes

  • PeripheralManager