How to start with lego nxt?

This tutorial is for Windows, if you want a Mac tutorial please contact us :P


So, you want to use your Lego Mindstorm NXT!!

That’s Great, be part of the Robotic Team Re-bot :D

Here are the instructions before you plug-in your NXT, for simple reference we are going to call it Minion.

Now, let’s start!

The package of the LegoKit that it’s mentioned in the tutorial, you can find it at the end of this tutorial.

First of all check out which operating system type you have whether the 64-bits or the 32-btis. To do this, you go to Windows (Start) -> Computer (Right Click) -> Properties, then a window will appear where you can find a summary of your computer technical information.

Look up for “System Type” and it will look something like this if your have a 64-bit:

“System Type: 64-bit Operating System” Or “System Type: 32-bit Operating System”

1.If your computer is x64, if not go to step 2.
Inside the folder LegoKit there is a zip called “PhantomDriver_Download1", be sure that it is the
latest version.
Then you found it, decompress and run the “setup.exe” and follow the instructions that will guide you easily. (You just have to press next and Finalize).

You have to download the Phantom Driver and install it in your computer, you can do this entering to the official site of LEGO and search Phantom Driver, it is important to download the latest version. Here is the web site:

Did you success? How do you know this? Well check out in your Control Panel->Programs-> Programs and Features or Uninstall a Program where you have to be able to see a program call “LEGO MINDSTORM NXT Driver for x64"

Everything ok? Excellent!! Great Work!!.

2. Do you have Java installed in your computer? (Yes, go to step 3).
How to know if you have java?, well go to Control Panel -> Programs -> Programs and Features or Uninstall a Program, and look up for Java.

Obviously if you don’t have any program call Java you don’t have install it, if you found one it have to look like this:

“Java 7 Update 25" without the 64-bit.
For our minion we need to install a 32-bit version of Java, which you can found in the folder LegoKit->Instaladores and .exe call “jdk-7u25-windows-i586". You just have to run it and follow the

You can download it from the official oracle web-site, REMEMBER YOU HAVE TO DOWNLOAD THE 32-BIT VERSION OF JDK!!!!. IF YOU DON’T, THIS WON’T WORK. Here is the web site:

It’s the one of Java SE Development Kit/Windows x86!! and accept the license agreement.

To check out that you installed correctly you can got to step 3.
If you are sure, go to step 4. You have it!!!?? Wonderful!! :P Let’s continue
3. Is your java the one of 32 bits? (Yes, step 4).
How to know which version of java you have?, well go to Control Panel -> Programs -> Programs and Features or Uninstall a Program and look up for Java, if you have the of 64 bits, it will look like this:

“Java 7 Update 25 (64-bit)”

So, we’re looking something like this:

“Java 7 Update 25"

If you don’t have it take a look in the step number 2.

4. You have to install the leJOS software which is going to help you to connect and use your LEGO. Inside the folder LegoKit->Instaladores there is “leJOS_NXJ_0.9.1beta-3_win32_setup.exe”.

After you found it, run the .exe and again follow the instructions, notice that there is a step where you have to link your software leJOS_NXJ to a Java installation (jdk). Be sure that you are linking the software to the java (jdk) of 32 bits, (If you don’t have a 32 bits installation go to step 3).

Download it from this site:

5. Awesome! you have installed almost everything. Now we have to set the environmental variables to work with it.

We are going to navigate to Windows (Start) -> Computer (Right Click) -> Properties. There, on the left panel you click on the Advanced system settings, a window will appear.

Then look up for the button that says “Environment Variables” and click on it, which will open an other window. Now, when we installed leJOS, it automatically create us a variable, which you will be able to find it in the “User variables for USER” segment (the first table). It should be something like this:

“NXJ_HOME C:\Program Files (x86)\leJOS NXJ” If not, you did something wrong, return to step 4.

Ready? Well now take a look in the next table which is under the label of “System variables”, and find in the Variable column “Path”, click on it and press the “Edit”, the button is below. And guess what? Yes an other little window is open. There is a label “Variable value” click on the text box in the right side. DON’T ERASE ANYTHING!!!! and go to the end of all the text, write a semicolon and the path where your Java 32 bit installation is, something like:

“C:\Program Files (x86)\Java\jdk1.7.0_25\bin”

Finally, in the package of you can find an installer for NetBeans, but you can use any IDE (java) of your preference, and run the project LegoFrame which can be found inside the zip or in github in the next link:

*The package of all the functions of Lego nxj, are included in classes.jar which is inside the project.

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