Keiko on Mindstorms
Alternative firmware for the Mindstorms robot controller provides an implementation of the JVM, allowing Java programs to run on the controller, subject to some restrictions. Using this firmware as a guide, produce an interpreter for a suitable bytecode, perhaps some variant of Keiko, allowing Oberon or another robot language of your own design to run on the controller. Aim to support the buttons and display at first, and perhaps add control of the motors and sensors later.
Please see http://spivey.oriel.ox.ac.uk/corner/Undergraduate_and_M.Sc._projects for further details.