You need to be the super-user to do some, or all of this.


1) Go to http://www.rxtx.org and download 

   rxtx-2.1-7-bins-r2.zip (Final)

   You want the version that uses the namespace (gnu.io).
   Unzip the file and follow the instructions in the
   INSTALL file for Linux. For SuSE Linux:

   # mv rxtx-2.1-7-bins-r2/RXTXcomm.jar /usr/lib/java/jre/lib/ext
   # mv rxtx-2.1-7-bins-r2/Linux/i686-unknown-linux-gnu/librxtxSerial.so /usr/lib/java/jre/lib/i386

   does the job.

2) Go to http://lejos.sourceforge.net and download

   icommand_0.4.zip

   Put it in a new directory --- mindstorms, say --- and
   unzip it. In the mindstorms directory, do 

   # CLASSPATH=`pwd`/icommand.jar:.
   # export CLASSPATH

3) In the mindstorms/samples directory, save this test program

   import java.util.*;
   import gnu.io.*;
   public class Test {
     public static void main(String[] args) {
       Enumeration en = CommPortIdentifier.getPortIdentifiers();
       while (en.hasMoreElements()) {
         CommPortIdentifier cpi = (CommPortIdentifier) en.nextElement();
         System.out.println("name=" + cpi.getName());
       }
     }
   }
  
   and compile it with

   # javac Test.java

4) Insert your Bluetooth dongle into the USB port. Linux will
   detect the new hardware. Say yes to the dialog inviting you 
   to configure it, check "Enable Bluetooth Services", set the
   four-digit Local PIN for Incoming Connections to "1234", and
   then "Finish".

5) Switch on your Lego NXT brick. Press the left arrow until
   you reach the Bluetooth symbol. Press the orange button.
   Press the left arrow until you reach On/Off. Press the 
   orange button to turn Bluetooth on. A Bluetooth symbol
   should appear in the top left-hand corner of the display.
   Press the orange button again to return to "main menu"
   level.

6) Run the command

   # hcitool scan

   On my machine, this returns

	Scanning ...
        00:15:A0:58:8D:8F       Sirbastian
        00:14:A7:6D:C6:AA       Nokia 6230i
        00:16:53:02:31:7C       NXT

   One of the visible Bluetooth devices should be your NXT brick,
   with its unique number (mine is 00:16:53:02:31:7C).

7) Run the command

   # rfcomm bind /dev/rfcomm0 00:16:53:02:31:7C

   with the unique number obtained above.

8) Set the value of your serial port in the file icommand.properties

    In  the file icommand.properties set the value of nxtcomm to the value
    of your serial port, /dev/rfcomm0  Put the file icommand.properties
    into your home directory, or your working directory. To check the location
    and contents of the file, execute the command: java -jar icommand.jar

9) Run the test program you compiled earlier with

   # java -Dgnu.io.rxtx.SerialPorts=/dev/rfcomm0 Test

   The output should be

	Experimental:  JNI_OnLoad called.
	Stable Library
	=========================================
	Native lib Version = RXTX-2.1-7
	Java lib Version   = RXTX-2.1-7
	name=/dev/rfcomm0

10) Connect a motor to port A of the NXT brick.

11) Compile the program

    import icommand.platform.nxt.*;
    import icommand.nxtcomm.*;

    public class Wheel {
      public static void main(String[] args) {
        Motor.A.forward(30);
        NXTCommand.close();
      }
    }

    with

    # javac Wheel.java

    and run it with

    # java -Dgnu.io.rxtx.SerialPorts=/dev/rfcomm0 Wheel 

    This should cause the motor to run for a short time.
 
12) If that works, you are in business!