/** @see com.svhelloworld.knotlog.engine.sources.StreamedSource#open() */
@Override
public InputStream open() {
try {
// make sure the specified port is available
CommPortIdentifier identifier = CommPortIdentifier.getPortIdentifier(config.getName());
if (identifier.isCurrentlyOwned()) {
throw new SerialPortOccupiedException(
config.getName() + " port is currently opened by another application");
}
// open up the port
CommPort port = identifier.open(getOwnerName(), PORT_TIMEOUT);
if (port instanceof SerialPort) {
// configure serial port
serialPort = (SerialPort) port;
serialPort.setSerialPortParams(
config.getBaudRate(),
config.getDataBits().getRXTXConstant(),
config.getStopBit().getRXTXConstant(),
config.getParity().getRXTXConstant());
/*
* the following 2 lines fix the exception:
* "IOException: Underlying input stream returned zero bytes"
* that is thrown when we read from the InputStream.
*/
serialPort.enableReceiveTimeout(PORT_TIMEOUT);
serialPort.enableReceiveThreshold(0);
InputStream is = serialPort.getInputStream();
return is;
}
// not a serial port
throw new SerialPortException("must operate against a serial port");
} catch (PortInUseException e) {
throw new SerialPortOccupiedException(e.getMessage(), e);
} catch (Exception e) {
throw new SerialPortException(e.getMessage(), e);
}
}
/**
* Opens the Operation System Serial Port
*
* <p>This method opens the port and set Serial Port parameters according to the DSMR
* specification. Since the specification is clear about these parameters there are not
* configurable.
*
* <p>If there are problem while opening the port, it is the responsibility of the calling method
* to handle this situation (and for example close the port again).
*
* <p>Opening an already open port is harmless. The method will return immediately
*
* @return true if opening was successful (or port was already open), false otherwise
*/
private boolean open() {
synchronized (portLock) {
// Sanity check
if (portState != PortState.CLOSED) {
return true;
}
try {
// Opening Operating System Serial Port
logger.debug("Creating CommPortIdentifier");
CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(portName);
logger.debug("Opening CommPortIdentifier");
CommPort commPort = portIdentifier.open("org.openhab.binding.dsmr", readTimeoutMSec);
logger.debug("Configure serial port");
serialPort = (SerialPort) commPort;
serialPort.enableReceiveThreshold(1);
serialPort.enableReceiveTimeout(readTimeoutMSec);
// Configure Serial Port based on specified port speed
logger.debug("Configure serial port speed " + portSpeed);
switch (portSpeed) {
case LOW_SPEED:
serialPort.setSerialPortParams(
9600, SerialPort.DATABITS_7, SerialPort.STOPBITS_1, SerialPort.PARITY_EVEN);
serialPort.setDTR(false);
serialPort.setRTS(true);
break;
case HIGH_SPEED:
serialPort.setSerialPortParams(
115200, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
break;
default:
logger.error("Invalid speed, closing port");
return false;
}
} catch (NoSuchPortException nspe) {
logger.error("Could not open port: " + portName, nspe);
return false;
} catch (PortInUseException piue) {
logger.error("Port already in use: " + portName, piue);
return false;
} catch (UnsupportedCommOperationException ucoe) {
logger.error("Port is not suitable: " + portName, ucoe);
return false;
}
// SerialPort is ready, open the reader
logger.info("SerialPort opened successful");
try {
bis = new BufferedInputStream(serialPort.getInputStream());
} catch (IOException ioe) {
logger.error("Failed to get inputstream for serialPort. Closing port", ioe);
return false;
}
logger.info("DSMR Port opened successful");
return true;
}
}