It’s based around an Arduino and is a platform similar to the Parallax Boe-Bot. The Arduino sends PWM signals to continuos rotation servos that drive the two main wheels.

An arduino with a 2 axis joystick + 1 button, send the data via serial to the pc, and in the pc I use PPJoyCOM, so I can use it like a real joystick in any game.

The joystick x-axis is attached to Arduino pin A0 and the y-axis to Arduino A1, and these are our INPUT. The x- and y-axes are then set as variables for movement.