com.sun.spot.peripheral
Interface II2C

All Superinterfaces:

IResource

All Known Implementing Classes:

AT91_I2C, ATmega_I2C

public interface II2C
extends IResource

Interface for communicating with devices using the I2C protocol.

Author:

Ron Goldman

Method Summary

void	close() Release any resources associated with the I2C hardware.
boolean	isBusy() Check if an I2C data transfer is currently in process.
void	open() Initialize the I2C hardware.
boolean	probe(int slaveAddress, int probeData) Check if a slave device is present at the given address.
void	read(int slaveAddress, byte[] data, int off, int len) Read data from the specified I2C slave device.
void	read(int slaveAddress, int internalAddress, int internalAddressSize, byte[] data, int off, int len) Read data from the specified I2C slave device.
void	setClockSpeed(int clockSpeed) Set the clock speed to use for I2C data transfers.
void	write(int slaveAddress, byte[] data, int off, int len) Write data to the specified I2C slave device.
void	write(int slaveAddress, int internalAddress, int internalAddressSize, byte[] data, int off, int len) Write data to the specified I2C slave device.

Methods inherited from interface com.sun.spot.resources.IResource

addTag, getTags, getTagValue, hasTag, removeTag

Method Detail

open

void open()
          throws IOException

Initialize the I2C hardware.

Throws:

IOException

close

void close()
           throws IOException

Release any resources associated with the I2C hardware.

Throws:

IOException

setClockSpeed

void setClockSpeed(int clockSpeed)

Set the clock speed to use for I2C data transfers.

Parameters:

clockSpeed - I2C bus clock in Hertz

write

void write(int slaveAddress,
           byte[] data,
           int off,
           int len)
           throws IOException

Write data to the specified I2C slave device.

Parameters:

slaveAddress - 7-bit slave address, shifted left one bit so LSB is not used

data - Array of bytes to write

off - Offset from which to start writing data

len - How many bytes of data to write. Note: some implementations may limit the number of bytes that can be written in a single call, e.g. the eDemo board firmware has a fixed buffer that can only hold 40 bytes.

Throws:

IOException

write

void write(int slaveAddress,
           int internalAddress,
           int internalAddressSize,
           byte[] data,
           int off,
           int len)
           throws IOException

Write data to the specified I2C slave device.

Parameters:

slaveAddress - 7-bit slave address, shifted left one bit so LSB is not used

internalAddress - 0-4 bytes of internal address information sent to the slave device before any data; Note: some implementations may not support sending a full 4 bytes of data, e.g. the ARM9 can only send 0-3 bytes

internalAddressSize - how many bytes of internal address information are to be sent

data - Array of bytes to write

off - Offset from which to start writing data

len - How many bytes of data to write. Note: some implementations may limit the number of bytes that can be written in a single call, e.g. the eDemo board firmware has a fixed buffer that can only hold 40 bytes.

Throws:

IOException

read

void read(int slaveAddress,
          byte[] data,
          int off,
          int len)
          throws IOException

Read data from the specified I2C slave device.

Parameters:

slaveAddress - 7-bit slave address, shifted left one bit so LSB is not used

data - Array of bytes to read into

off - Offset from which to start reading data

len - How many bytes of data to read. Note: some implementations may limit the number of bytes that can be written in a single call, e.g. the eDemo board firmware has a fixed buffer that can only hold 40 bytes.

Throws:

IOException

read

void read(int slaveAddress,
          int internalAddress,
          int internalAddressSize,
          byte[] data,
          int off,
          int len)
          throws IOException

Read data from the specified I2C slave device.

Parameters:

slaveAddress - 7-bit slave address, shifted left one bit so LSB is not used

internalAddress - 0-4 bytes of internal address information sent to the slave device before any data; Note: some implementations may not support sending a full 4 bytes of data, e.g. the ARM9 can only send 0-3 bytes

internalAddressSize - how many bytes of internal address information are to be sent

data - Array of bytes to read into

off - Offset from which to start reading data

len - How many bytes of data to read. Note: some implementations may limit the number of bytes that can be written in a single call, e.g. the eDemo board firmware has a fixed buffer that can only hold 40 bytes.

Throws:

IOException

isBusy

boolean isBusy()

Check if an I2C data transfer is currently in process.

Returns:

true if a data transfer is currently in process

probe

boolean probe(int slaveAddress,
              int probeData)

Check if a slave device is present at the given address. Tries to write a byte to the device and sees if it gets a NACK.

Parameters:

slaveAddress - 7-bit slave address, shifted left one bit so LSB is not used

probeData - - byte value to try writing to device

Returns:

false if no device is present