Lejos NXJ extension for BlueJ

Legal notice : use at your own risk


UPDATE (13th September 2012)

With the latest version of LeJOS, there is a requirement for windows NT and above. Unfortunately the last version of the plugin did not pass the OS to the LeJOS system and LeJOS decided it could not complete any task until it knew the correct version. The short term bodge is for the plugin to check if the OS is 'Wind*' and if so, make LeJOS think it is Windows_NT.
I am not as yet certain what will happen when this is run on Windows XP with the latest version of LeJOS....you have been warned!

Installing the extension

The extension is very simple and allows Java applications to be developed in BlueJ which can then be uploaded and run.


Pre-requisite: you have installed and have working the Lejos software http://lejos.sourceforge.net/ (version 0.9.1)


Step 1: Download the file LeJOSNXTExtension.jar

Step 2: Save the file in the <somewhere>/BlueJ/lib/extensions folder (ref BlueJ extensions directories)

Step 3: Start BlueJ

Step 4: Click on the 'Tools' menu and then choose Preferences

Step 5: Click on the Libraries tab and then Add

Step 6: Find the file classes.jar in the <NXJ_HOME>/lib/nxt folder

Step 7: Click OK

Step 8: In Tools->Preferences->Extensions(tab) enter the location of the lejos_nxj directory e.g. c:/lejos_nxj or /home/me/lejos_nxj. (optionally enter the bluetooth address of your Lego robot in the address box.)

Step 9: RESTART BlueJ


Running programs

In the Class diagram window, right click on the main class, select NXT option and then one of the six NXT specific options (some refer to usb (e.g. NXJ_UPLOADUSB) and others bluetooth (e.g. NXJ-RUNBT)).


A window appears showing progress etc



Have fun. :-)


David Bowes: University of Hertfordshire


If you want to e-mail me about the plugins, please use the link below and DON'T change the subject