com.pi4j.io.i2c.impl.I2CDeviceImpl Maven / Gradle / Ivy
package com.pi4j.io.i2c.impl;
/*
* #%L
* **********************************************************************
ORGANIZATION : Pi4J
PROJECT : Pi4J :: Java Library (Core)
FILENAME : I2CDeviceImpl.java
This file is part of the Pi4J project. More information about
this project can be found here: http://www.pi4j.com/
**********************************************************************
* %%
* Copyright (C) 2012 - 2018 Pi4J
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
import com.pi4j.io.i2c.I2CDevice;
/**
* Implementation of i2c device. This class only holds reference to i2c bus (so it can use its handle) and device address.
*
* @author Daniel Sendula, refactored by RasPelikan
*
*/
public class I2CDeviceImpl implements I2CDevice {
/**
* Reference to i2c bus
*/
private I2CBusImpl bus;
/**
* I2c device address
*/
private int deviceAddress;
/**
* @return The address for which this instance is constructed for.
*/
@Override
public int getAddress() {
return deviceAddress;
}
/**
* Constructor.
*
* @param bus i2c bus
* @param address i2c device address
*/
public I2CDeviceImpl(I2CBusImpl bus, int address) {
this.bus = bus;
this.deviceAddress = address;
}
/**
* Used by WriteRunnables and ReadRunnables.
*
* @return The bus associated with this I2CDeviceImpl instance.
*/
I2CBusImpl getBus() {
return bus;
}
/**
* This method writes one byte to i2c device.
*
* @param data byte to be written
*
* @throws IOException thrown in case byte cannot be written to the i2c device or i2c bus
*/
@Override
public void write(final byte data) throws IOException {
getBus().writeByteDirect(this, data);
}
/**
* This method writes several bytes to the i2c device from given buffer at given offset.
*
* @param data buffer of data to be written to the i2c device in one go
* @param offset offset in buffer
* @param size number of bytes to be written
*
* @throws IOException thrown in case byte cannot be written to the i2c device or i2c bus
*/
@Override
public void write(final byte[] data, final int offset, final int size) throws IOException {
getBus().writeBytesDirect(this, size, offset, data);
}
/**
* This method writes all bytes included in the given buffer directly to the i2c device.
*
* @param buffer buffer of data to be written to the i2c device in one go
*
* @throws IOException thrown in case byte cannot be written to the i2c device or i2c bus
*/
@Override
public void write(byte[] buffer) throws IOException {
write(buffer, 0, buffer.length);
}
/**
* This method writes one byte to i2c device.
*
* @param address local address in the i2c device
* @param data byte to be written
*
* @throws IOException thrown in case byte cannot be written to the i2c device or i2c bus
*/
@Override
public void write(final int address, final byte data) throws IOException {
getBus().writeByte(this, address, data);
}
/**
* This method writes several bytes to the i2c device from given buffer at given offset.
*
* @param address local address in the i2c device
* @param data buffer of data to be written to the i2c device in one go
* @param offset offset in buffer
* @param size number of bytes to be written
*
* @throws IOException thrown in case byte cannot be written to the i2c device or i2c bus
*/
@Override
public void write(final int address, final byte[] data, final int offset, final int size) throws IOException {
getBus().writeBytes(this, address, size, offset, data);
}
/**
* This method writes all bytes included in the given buffer directoy to the register address on the i2c device
*
* @param address local address in the i2c device
* @param buffer buffer of data to be written to the i2c device in one go
*
* @throws IOException thrown in case byte cannot be written to the i2c device or i2c bus
*/
public void write(int address, byte[] buffer) throws IOException {
write(address, buffer, 0, buffer.length);
}
/**
* This method reads one byte from the i2c device. Result is between 0 and 255 if read operation was successful, else a negative number for an error.
*
* @return byte value read: positive number (or zero) to 255 if read was successful. Negative number if reading failed.
*
* @throws IOException thrown in case byte cannot be read from the i2c device or i2c bus
*/
@Override
public int read() throws IOException {
return getBus().readByteDirect(this);
}
/**
*
* This method reads bytes from the i2c device to given buffer at asked offset.
*
*
*
* Note: Current implementation calls {@link #read(int)}. That means for each read byte i2c bus will send (next) address to i2c device.
*
*
* @param data buffer of data to be read from the i2c device in one go
* @param offset offset in buffer
* @param size number of bytes to be read
*
* @return number of bytes read
*
* @throws IOException thrown in case byte cannot be read from the i2c device or i2c bus
*/
@Override
public int read(final byte[] data, final int offset, final int size) throws IOException {
return getBus().readBytesDirect(this, size, offset, data);
}
/**
* This method reads one byte from the i2c device. Result is between 0 and 255 if read operation was successful, else a negative number for an error.
*
* @param address local address in the i2c device
* @return byte value read: positive number (or zero) to 255 if read was successful. Negative number if reading failed.
*
* @throws IOException thrown in case byte cannot be read from the i2c device or i2c bus
*/
@Override
public int read(final int address) throws IOException {
return getBus().readByte(this, address);
}
/**
*
* This method reads bytes from the i2c device to given buffer at asked offset.
*
*
*
* Note: Current implementation calls {@link #read(int)}. That means for each read byte i2c bus will send (next) address to i2c device.
*
*
* @param address local address in the i2c device
* @param data buffer of data to be read from the i2c device in one go
* @param offset offset in buffer
* @param size number of bytes to be read
*
* @return number of bytes read
*
* @throws IOException thrown in case byte cannot be read from the i2c device or i2c bus
*/
@Override
public int read(final int address, final byte[] data, final int offset, final int size) throws IOException {
return getBus().readBytes(this, address, size, offset, data);
}
/**
* @see com.pi4j.io.file.LinuxFile#ioctl(long, int)
*/
@Override
public void ioctl(long command, int value) throws IOException {
getBus().ioctl(this, command, value);
}
/**
* @see com.pi4j.io.file.LinuxFile#ioctl(long, ByteBuffer, IntBuffer)
*/
@Override
public void ioctl(long command, ByteBuffer data, IntBuffer offsets) throws IOException {
getBus().ioctl(this, command, data, offsets);
}
/**
* This method writes and reads bytes to/from the i2c device in a single method call
*
* @param writeData buffer of data to be written to the i2c device in one go
* @param writeOffset offset in write buffer
* @param writeSize number of bytes to be written from buffer
* @param readData buffer of data to be read from the i2c device in one go
* @param readOffset offset in read buffer
* @param readSize number of bytes to be read
*
* @return number of bytes read
*
* @throws IOException thrown in case byte cannot be read from the i2c device or i2c bus
*/
@Override
public int read(final byte[] writeData, final int writeOffset, final int writeSize, final byte[] readData, final int readOffset, final int readSize) throws IOException {
return getBus().writeAndReadBytesDirect(this, writeSize, writeOffset, writeData, readSize, readOffset, readData);
}
/**
* This helper method creates a string describing bus file name and device address (in hex).
*
* @return string with all details
*/
protected String makeDescription() {
return "I2CDevice on " + bus + " at address 0x" + Integer.toHexString(deviceAddress);
}
/**
* This helper method creates a string describing bus file name, device address (in hex) and local i2c address.
*
* @param address local address in i2c device
* @return string with all details
*/
protected String makeDescription(int address) {
return "I2CDevice on " + bus + " at address 0x" + Integer.toHexString(deviceAddress) + " to address 0x" + Integer.toHexString(address);
}
}