io.github.robolib.module.iface

Class I2C

java.lang.Object

io.github.robolib.module.iface.Interface

io.github.robolib.module.iface.I2C

Direct Known Subclasses:

ADXL345_I2C, ArdEx, HMC5883L, LCD2004, MPU6050

public class I2C
extends Interface

I2C bus interface class.

Author:

noriah

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	I2C.Port Enum representation of I2C ports on the RIO

Nested classes/interfaces inherited from class io.github.robolib.module.iface.Interface

Interface.InterfaceType

Field Summary

Fields

Modifier and Type	Field and Description
private static boolean[]	INITIALIZED_PORTS
protected byte	m_address
protected byte	m_port

Fields inherited from class io.github.robolib.module.iface.Interface

m_ifaceType, MAX_ANALOG_IN_CHANNELS, MAX_ANALOG_OUT_CHANNELS, MAX_DIGITAL_CHANNELS, MAX_PWM_CHANNELS, MAX_RELAY_CHANNELS

Constructor Summary

Constructors

Constructor and Description
I2C(I2C.Port port, int address) Constructor.
I2C(int address)

Method Summary

Modifier and Type	Method and Description
void	broadcast(int reg, int data) Send a broadcast write to all devices on the I2C bus.
boolean	checkAddress() Attempt to address a device on the I2C bus.
void	free() Destructor.
boolean	read(int reg, byte[] buffer, int count) Execute a read transaction with the device.
boolean	readBit(int reg, int bit) Read a single bit from an 8-bit device register.
boolean	readBit(int reg, int bit, byte[] data) Read a single bit from an 8-bit device register.
boolean	readBits(int reg, int bitStart, int length, byte[] data) Read multiple bits from an 8-bit device register.
boolean	readByte(int reg, byte[] data) Read single byte from an 8-bit device register.
boolean	readBytes(int reg, byte[] data, int length) Read multiple bytes from an 8-bit device register.
boolean	readOnly(byte[] buffer, int count) Execute a read only transaction with the device.
boolean	readWord(int reg, short[] data) Read single word from a 16-bit device register.
boolean	readWords(int reg, short[] data, int length) Read multiple words from a 16-bit device register.
boolean	transaction(byte[] dataToSend, int sendSize, byte[] dataReceived, int receiveSize) Generic transaction.
boolean	verifySensor(int reg, int count, byte[] expected) Verify that a device's registers contain expected values.
boolean	write(int reg, int data) Execute a write transaction with the device.
boolean	writeBit(int reg, int bit, boolean value) write a single bit in an 8-bit device register.
boolean	writeBit(int reg, int bit, byte value) write a single bit in an 8-bit device register.
boolean	writeBits(int reg, int bitStart, int length, byte data) Write multiple bits in an 8-bit device register.
boolean	writeBulk(byte[] data) Execute a write transaction with the device.
boolean	writeByte(int reg, byte data) Write single byte to an 8-bit device register.
boolean	writeBytes(int reg, byte[] data, int length) Write multiple bytes to an 8-bit device register.
boolean	writeWord(int reg, short data) Write single word to a 16-bit device register.
boolean	writeWords(int reg, short[] data, int length) Write multiple words to a 16-bit device register.

Methods inherited from class io.github.robolib.module.iface.Interface

allocateMXPPin, checkAnalogInputChannel, checkAnalogOutputChannel, checkDigitalChannel, checkPWMChannel, checkRelayChannel, freeMXPPin, getInterfaceType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_port

protected final byte m_port

m_address

protected final byte m_address

INITIALIZED_PORTS

private static final boolean[] INITIALIZED_PORTS

Constructor Detail

I2C

public I2C(int address)

I2C

public I2C(I2C.Port port,
           int address)

Constructor.

Parameters:

port - The I2C port the device is connected to.

address - The address of the device on the I2C bus.

Method Detail

free

public void free()

Destructor.

transaction

public final boolean transaction(byte[] dataToSend,
                                 int sendSize,
                                 byte[] dataReceived,
                                 int receiveSize)

Generic transaction. This is a lower-level interface to the I2C hardware giving you more control over each transaction.

Parameters:

dataToSend - Buffer of data to send as part of the transaction.

sendSize - Number of bytes to send as part of the transaction.

dataReceived - Buffer to read data into.

receiveSize - Number of bytes to read from the device.

Returns:

Status of operation (true = success)

checkAddress

public final boolean checkAddress()

Attempt to address a device on the I2C bus. This allows you to figure out if there is a device on the I2C bus that responds to the address specified in the constructor.

Returns:

Status of operation (true = success)

write

public final boolean write(int reg,
                           int data)

Execute a write transaction with the device. Write a single byte to a register on a device and wait until the transaction is complete.

Parameters:

reg - The address of the register on the device to be written.

data - The byte to write to the register on the device.

Returns:

Status of operation (true = success)

writeBulk

public final boolean writeBulk(byte[] data)

Execute a write transaction with the device. Write multiple bytes to a register on a device and wait until the transaction is complete.

Parameters:

data - The data to write to the device.

Returns:

Status of operation (true = success)

writeBit

public final boolean writeBit(int reg,
                              int bit,
                              byte value)

write a single bit in an 8-bit device register.

Parameters:

reg - Register regAddr to write to

bit - Bit position to write (0-7)

value - New bit value to write

Returns:

Status of operation (true = success)

writeBit

public final boolean writeBit(int reg,
                              int bit,
                              boolean value)

write a single bit in an 8-bit device register.

Parameters:

reg - Register regAddr to write to

bit - Bit position to write (0-7)

value - New bit value to write

Returns:

Status of operation (true = success)

writeBits

public final boolean writeBits(int reg,
                               int bitStart,
                               int length,
                               byte data)

Write multiple bits in an 8-bit device register.

Parameters:

reg - Register regAddr to write to

bitStart - First bit position to write (0-7)

length - Number of bits to write (not more than 8)

data - Right-aligned value to write

Returns:

Status of operation (true = success)

writeByte

public final boolean writeByte(int reg,
                               byte data)

Write single byte to an 8-bit device register.

Parameters:

reg - Register address to write to

data - New byte value to write

Returns:

Status of operation (true = success)

writeWord

public final boolean writeWord(int reg,
                               short data)

Write single word to a 16-bit device register.

Parameters:

reg - Register address to write to

data - New word value to write

Returns:

Status of operation (true = success)

writeBytes

public final boolean writeBytes(int reg,
                                byte[] data,
                                int length)

Write multiple bytes to an 8-bit device register.

Parameters:

reg - First register address to write to

data - Buffer to copy new data from

length - Number of bytes to write

Returns:

Status of operation (true = success)

writeWords

public final boolean writeWords(int reg,
                                short[] data,
                                int length)

Write multiple words to a 16-bit device register.

Parameters:

reg - First register address to write to

data - Buffer to copy new data from

length - Number of words to write

Returns:

Status of operation (true = success)

readBit

public final boolean readBit(int reg,
                             int bit,
                             byte[] data)

Read a single bit from an 8-bit device register.

Parameters:

reg - Register regAddr to read from

bit - Bit position to read (0-7)

data - Container for single bit value

Returns:

Status of read operation (true = success)

readBit

public final boolean readBit(int reg,
                             int bit)

Read a single bit from an 8-bit device register.

Parameters:

reg - Register regAddr to read from

bit - Bit position to read (0-7)

Returns:

the value of the bit as a boolean

readBits

public final boolean readBits(int reg,
                              int bitStart,
                              int length,
                              byte[] data)

Read multiple bits from an 8-bit device register.

Parameters:

reg - Register regAddr to read from

bitStart - First bit position to read (0-7)

length - Number of bits to read (not more than 8)

data - Container for right-aligned value (i.e. '101' read from any bitStart position will equal 0x05)

Returns:

Status of read operation (true = success)

readByte

public final boolean readByte(int reg,
                              byte[] data)

Read single byte from an 8-bit device register.

Parameters:

reg - Register regAddr to read from

data - Container for byte value read from device

Returns:

Status of read operation (true = success)

readWord

public final boolean readWord(int reg,
                              short[] data)

Read single word from a 16-bit device register.

Parameters:

reg - Register regAddr to read from

data - Container for word value read from device

Returns:

Status of read operation (true = success)

readBytes

public final boolean readBytes(int reg,
                               byte[] data,
                               int length)

Read multiple bytes from an 8-bit device register.

Parameters:

reg - First register regAddr to read from

data - Buffer to store read data in

length - Number of bytes to read

Returns:

Status of read operation (true = success)

readWords

public final boolean readWords(int reg,
                               short[] data,
                               int length)

Read multiple words from a 16-bit device register.

Parameters:

reg - First register regAddr to read from

data - Buffer to store read data in

length - Number of words to read

Returns:

Status of read operation (true = success)

read

public final boolean read(int reg,
                          byte[] buffer,
                          int count)

Execute a read transaction with the device. Read bytes from a device. Most I2C devices will auto-increment the register pointer internally allowing you to read consecutive registers on a device in a single transaction.

Parameters:

reg - The register to read first in the transaction.

buffer - A pointer to the array of bytes to store the data read from the device.

count - The number of bytes to read in the transaction.

Returns:

Status of operation (true = success)

readOnly

public final boolean readOnly(byte[] buffer,
                              int count)

Execute a read only transaction with the device. Read 1 to 7 bytes from a device. This method does not write any data to prompt the device.

Parameters:

buffer - A pointer to the array of bytes to store the data read from the device.

count - The number of bytes to read in the transaction.

Returns:

Status of operation (true = success)

broadcast

public final void broadcast(int reg,
                            int data)

Send a broadcast write to all devices on the I2C bus. This is not currently implemented!

Parameters:

reg - The register to write on all devices on the bus.

data - The value to write to the devices.

verifySensor

public final boolean verifySensor(int reg,
                                  int count,
                                  byte[] expected)

Verify that a device's registers contain expected values. Most devices will have a set of registers that contain a known value that can be used to identify them. This allows an I2C device driver to easily verify that the device contains the expected value.

Parameters:

reg - The base register to start reading from the device.

count - The size of the field to be verified.

expected - A buffer containing the values expected from the device.

Returns:

true if the sensor was verified to be connected