/**
* Copyright (c) 2010-2014, openHAB.org and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*/
package org.openhab.binding.swegonventilation.protocol;
import java.io.IOException;
import java.io.InputStream;
import gnu.io.CommPort;
import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import org.apache.commons.io.IOUtils;
import org.openhab.binding.swegonventilation.internal.SwegonVentilationException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Connector for serial port communication.
*
* @author Pauli Anttila
* @since 1.4.0
*/
public class SwegonVentilationSerialConnector extends
SwegonVentilationConnector {
private static final Logger logger = LoggerFactory
.getLogger(SwegonVentilationSerialConnector.class);
static final int BAUDRATE = 38400;
String portName = null;
SerialPort serialPort = null;
InputStream in = null;
public SwegonVentilationSerialConnector(String portName) {
this.portName = portName;
}
@Override
public void connect() throws SwegonVentilationException {
try {
CommPortIdentifier portIdentifier = CommPortIdentifier
.getPortIdentifier(portName);
CommPort commPort = portIdentifier.open(this.getClass().getName(),
2000);
serialPort = (SerialPort) commPort;
serialPort.setSerialPortParams(BAUDRATE, SerialPort.DATABITS_8,
SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
in = serialPort.getInputStream();
logger.debug("Swegon ventilation Serial Port message listener started");
} catch (Exception e) {
throw new SwegonVentilationException(e);
}
}
@Override
public void disconnect() throws SwegonVentilationException {
logger.debug("Disconnecting");
if (in != null) {
logger.debug("Close serial in stream");
IOUtils.closeQuietly(in);
}
if (serialPort != null) {
logger.debug("Close serial port");
serialPort.close();
}
serialPort = null;
in = null;
logger.debug("Closed");
}
@Override
public byte[] receiveDatagram() throws SwegonVentilationException {
if (in == null) {
connect();
}
byte[] buffer = new byte[1024];
byte[] message = new byte[1024];
int len = -1;
int msgLen = 0;
boolean start_found = false;
int index = 0;
try {
while ((len = this.in.read(buffer)) > 0) {
for (int i = 0; i < len; i++) {
if (buffer[i] == (byte) 0xCC) {
start_found = true;
index = 0;
msgLen = 0;
} else if (start_found) {
message[index++] = buffer[i];
if (index == 5) {
if (message[0] == (byte) 0x64) {
msgLen = message[4];
}
}
if (msgLen > 0 && index == (5 + msgLen + 2)) {
int calculatedCRC = calculateCRC(message, index - 2);
int msgCRC = toInt(message[5 + msgLen],
message[5 + msgLen + 1]);
if (msgCRC == calculatedCRC) {
byte[] data = new byte[5 + msgLen];
for (int j = 0; j < (5 + msgLen); j++)
data[j] = message[j];
return data;
} else {
throw new SwegonVentilationException(
"CRC does not match");
}
}
}
}
}
} catch (IOException e) {
throw new SwegonVentilationException(
"Error occured while receiving data", e);
}
return null;
}
}