In order to program LEGO Mindstorms with Java, we need to do several steps. One of them is create a bootable SD Card. Why do we need a bootable SD Card? We need it because the robot will start through the SD Card. The SD card will contain Java SE Embedded Virtual Machine (JVM) and the leJOS classes.
The first requirement is: Linux Operational System, more specifically Ubuntu(12.10 is more recommended) . You can use Ubuntu in a Virtual Machine, for example using Virtual Box. I'm using Ubuntu as my second Operational System. I chose it because I'm going to deal with hardware interaction such as SD Card, wireless. For these reasons I chose to run Linux beside Windows.
After that, you have to download leJOS for Mindstorms EV3. The followed link will show some folder with different versions:
http://sourceforge.net/projects/lejos/files/lejos-EV3/
I chose the newest one: http://sourceforge.net/projects/lejos/files/lejos-EV3/0.4.0-alpha/
Download the file lejosimage.bz2 to your Ubuntu. Unpack the file. It will create a folder called lejosimage.
Next, download Java SE Embedded JVM on http://www.oracle.com/technetwork/java/embedded/downloads/javase/javaseemeddedev3-1982511.html and copy the downloaded tar file to lejosimage directory.
Next, execute the file format_sdcard.sh into the terminal. You only have to follow the instructions given on terminal.
It will ask to make sure the card is not inserted. Then, it will ask the insert the card. Later, it will ask to type the system's password, and then will ask to type something like "sdb" or maybe "sda". It asked me "sdb". Finally, it will ask to remove the card. These steps are simple. Just read the instructions given carefully.
The next step is run the file update_sdcard.sh on terminal. It will ask the password, and then it will get your card ready.
