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.
getName
String getName ()
Returns the I/O name.
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 |
|
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 |
|
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 |
|
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 |
|
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 |
|
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 |
|
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 |
|
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 |
|