[Alan Anderson]

Direct mapping of joystick to motor is the easiest and most intuitive way to use two joysticks to control two motors. This year's TechnoKat robot does it the long way around, though, taking the average of the two sticks to control an internal "velocity" value, with the sticks' difference becoming a "turn" value. It essentially computes the equivalent of a single joystick. The output code remixes the velocity and turn values into two motor control numbers.

This complexity has its rewards. It makes navigating under autonomous control a wee bit simpler to implement, and it provides a straightforward way to implement speed-sensitive steering if desired. There are deadbands applied to the computed values, so it also theoretically makes driving straight at high speed slightly easier.