com.raspoid

Class I2CComponent

java.lang.Object

com.raspoid.I2CComponent

All Implemented Interfaces:

Component

Direct Known Subclasses:

AccelerometerADXL345, BarometerBMP180, LCM1602, MPU6050, PCA9685, PCF8591

public class I2CComponent
extends java.lang.Object
implements Component

This class is used as an abstraction for each i2c component of the framework. This povides usefull utilities to connect to, read data from and write data to i2c devices.

Field Summary

Fields

Modifier and Type	Field and Description
protected com.pi4j.io.i2c.I2CDevice	device The abstraction of the i2c device.
static int	MAX_I2C_ADDRESS The maximum available i2c device address is 0x77.
static int	MIN_I2C_ADDRESS The minimum available i2c device address is 0x03.

Constructor Summary

Constructors

Constructor and Description
I2CComponent(int i2cAddress) Constructor for a new i2c component, connected on the bus at the specific i2cAddress.

Method Summary

Modifier and Type	Method and Description
com.pi4j.io.i2c.I2CDevice	getDevice() Get the abstraction of the i2c device.
java.lang.String	getType() Get the String representation of the type of the component.
int	readSignedRegisterValue(int reg) Reads the content of the reg register (8bits), and returns the signed integer representation of this value in the -128..127 interval if read operation was successfull.
int	readTwoSignedRegsiters(int reg) Reads the signed content of two consecutive registers (reg and reg + 1) (16bits), and returns the big endian combination of those values.
int	readTwoUnsignedRegisters(int reg) Reads the unsigned content of two consecutive registers (reg and reg + 1) (16bits), and returns the big endian combination of those values.
int	readUnsignedRegisterValue(int reg) Reads the content of the reg register (8bits), and returns this value in the 0..255 interval if read operation was successfull.
void	writeUnsignedValueDirectlyToI2CDevice(int value) This method writes an unsigned value directly on the i2c device (not on a specific register on this device).
void	writeUnsignedValueToRegister(int reg, int value) This method writes an unsigned value on the i2c device, on a specific register of this device.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_I2C_ADDRESS

public static final int MAX_I2C_ADDRESS

The maximum available i2c device address is 0x77.

A seven bit wide address space theoretically allows 128 I2C addresses. However, some addresses are reserved for special purposes. Only 112 addresses are then available with the 7 bit address scheme.

See Also:

Constant Field Values

MIN_I2C_ADDRESS

public static final int MIN_I2C_ADDRESS

The minimum available i2c device address is 0x03.

A seven bit wide address space theoretically allows 128 I2C addresses. However, some addresses are reserved for special purposes. Thus, only 112 addresses are available with the 7 bit address scheme.

See Also:

Constant Field Values

device

protected com.pi4j.io.i2c.I2CDevice device

The abstraction of the i2c device. It allows data to be read or written to the device.

Constructor Detail

I2CComponent

public I2CComponent(int i2cAddress)

Constructor for a new i2c component, connected on the bus at the specific i2cAddress.

Parameters:

i2cAddress - the i2c device address of the corresponding component.

Method Detail

getDevice

public com.pi4j.io.i2c.I2CDevice getDevice()

Get the abstraction of the i2c device. It then allows data to be read or written to the device.

Returns:

the abstraction of the i2c device.

See Also:

I2CDevice

writeUnsignedValueDirectlyToI2CDevice

public void writeUnsignedValueDirectlyToI2CDevice(int value)

This method writes an unsigned value directly on the i2c device (not on a specific register on this device).

Parameters:

value - the unsigned value to be written on the device. This value must be in the 0..255 interval.

See Also:

I2CDevice.write(byte)

writeUnsignedValueToRegister

public void writeUnsignedValueToRegister(int reg,
                                         int value)

This method writes an unsigned value on the i2c device, on a specific register of this device.

Parameters:

reg - the destination register on the i2c device.

value - the unsigned value to be written on the device. This value must be in the 0..255 interval.

See Also:

I2CDevice.write(int, byte)

readUnsignedRegisterValue

public int readUnsignedRegisterValue(int reg)

Reads the content of the reg register (8bits), and returns this value in the 0..255 interval if read operation was successfull. A negative number is returned for an error.

Parameters:

reg - the local address on the i2c device where the data must be read.

Returns:

the byte value read on the device: a positive number in the 0..255 interval if reading was successful; a negative number (<0) if reading failed.

See Also:

I2CDevice.read(int), readSignedRegisterValue(int)

readSignedRegisterValue

public int readSignedRegisterValue(int reg)

Reads the content of the reg register (8bits), and returns the signed integer representation of this value in the -128..127 interval if read operation was successfull. A negative number under -128 is returned for an error.

Parameters:

reg - the local address on the i2c device where the data must be read.

Returns:

the integer signed representation of the byte value read on the device: a positive number in the -128..127 interval if reading was successful; a negative number (<128) if reading failed.

See Also:

readUnsignedRegisterValue(int)

readTwoUnsignedRegisters

public int readTwoUnsignedRegisters(int reg)

Reads the unsigned content of two consecutive registers (reg and reg + 1) (16bits), and returns the big endian combination of those values.

Parameters:

reg - the local address on the i2c device of the first register to be read.

Returns:

the unsigned big endian combination of the reads of registers reg and reg + 1 on the i2c device.

See Also:

readUnsignedRegisterValue(int)

readTwoSignedRegsiters

public int readTwoSignedRegsiters(int reg)

Reads the signed content of two consecutive registers (reg and reg + 1) (16bits), and returns the big endian combination of those values.

Parameters:

reg - the local address on the i2c device of the first register to be read.

Returns:

the signed big endian combination of the reads of registers reg and reg + 1 on the i2c device.

See Also:

readUnsignedRegisterValue(int), readSignedRegisterValue(int)

getType

public java.lang.String getType()

Description copied from interface: Component

Get the String representation of the type of the component.

Specified by:

getType in interface Component

Returns:

the String representation of the type of the component.