Using JVelbus

Using JVelbus in your code

The code fragment below shows the most basic steps to be taken to start using Velbus from your Java code.

public class JVelbusTest {

    private SerialBus bus;

    private boolean running;

    public JVelbusTest(){
        //Listening for Velbus responses is done is a separate thread.
        running = true;
        Worker worker = new Worker();
        Thread thread = new Thread(worker);
        thread.start();

        //Start scanning the Velbus.
        performScan();
    }

    public void performScan(){
        try{
            //Create a packet containing the command to send to Velbus.
            //These commands can be found in the module specification.
            //The command below performs a bus scan.
            Packet packet = new Packet();
            packet.setPacketPrioriy(Packet.LOW_PRIORITY);
            packet.setRtr(true);
            for(short i = 0x01 ; i <= 0xFF ; i++){
                packet.setAddress(i);
                bus.send(packet);
            }
            System.out.println("Scan completed.");
        }catch(ArgumentOutOfRangeException ex){
            ex.printStackTrace();
        }
    }

    public static void main(String[] args){
        new JVelbusTest();
    }

    private class Worker 
    implements Runnable, PacketSentListener, PacketReceivedListener{

        @Override
        public void packetReceivedEvent(PacketReceivedEvent event) {
            Packet packet = event.getPacket();
            System.out.println("R=" + packet.toString());
        }

        @Override
        public void packetSentEvent(PacketSentEvent event) {
            Packet packet = event.getPacket();
            System.out.println("S=" + packet.toString());
        }

        @Override
        public void run() {
            //Initiate communication to Velbus using the specified COM-port
            bus = new SerialBus("COM16");

            //Register event listeners for both packet received and 
            //packet send events (from the application point of view).
            bus.addPacketReceivedListener(this);
            bus.addPacketSentListener(this);

            //Start communication with the bus.
            bus.open();

            //We are just waiting for the bus to reply.
            while(running){
                try{
                    Thread.sleep(500);
                }catch(InterruptedException ex){}
            }

            //Unregister registered listeners.
            bus.removePacketReceivedListener(this);
            bus.removePacketSentListener(this);

            //IMPORTANT : always shutdown bus communication.
            //Not doing so results in a port in use exception during the
            //bus initialization!!
            bus.close();
        }        
    }
}

Please take in mind JVelbus only provides access at the lowest level to the Velbus. No methods are being provided to send, e.g., a switch on output X command on address XX.

The COM-port modifier used in the example is operating system dependent. The example above specifies a Microsoft Windows port identifier.