I'm creating a full documentation about it. So anyone will be able to read and follow it.
These tutorials will be followed by some Brazilian schools, helping students to create a similar project.
This is a simple project that we created in the last year to teach teens about Android, Arduino and robotics.
Interesting project. Also saw your code on Github but since it was in Portuguese I could not understand what was happening . It would be great if you could post it in English also so that I could comprehend it.