Hey everyone, I am one of the three students that worked on the PS2 adapter.
We used a 16f688 PIC chip and two dual pot digital potentiometers from Maxim. The device currently breaks the rules of official competition because it uses an external power source (9 volt battery). We are working on drawing power from the OI using the LED driver pins, since the circuit only draws around 6 miliamps of current. Since we got the beta working this weekend, we are now taking steps to finalize the design. We are working on soldering it together more permanently, so that you won't have to worry about wires, etc. coming loose on our messy breadboard. Once it's put together, we will be adding just a few more things, such as the drawing OI power thing. Once that's done, we will be posting up our PIC source code and schematics so other teams can build this device for themselves. It uses a conventional PS2 controller, any analog one will do, and it fully controls all the functions of our robot. (We used to use 3 joysticks for this.) It actually drives better this way because you can coordinate your actions more precisely without a second driver. (Sorry copilots
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The outputs are the 4 analog ones directly to the OI. Analog input 1/2 are the tank drive for the main robot. While 3/4 each send 4 digital inputs. This was done because we didn't have enough pins to use, so we had send multiple digital signals over analog.
Even if we won't get to use it in competition, it was still a fun project to work on, and we all learned a lot about PIC programming (we built our own programmer since we were on a budget) and electronics in general (Our software team did most of the electronics o_O).
BTW: The PS2 controller in the picture is not modified in any way, the wires are sticking out because it's a used controller. (Which is also why the trim is messed up and the robot tends to go backwards when not touching the sticks at times)