Here are my "scales" (la-la-la-la-la-la-la-la) for Designing For Constraints, specifically week 04. Keyboard emulators are usuall used to tweak videogame interfaces. Here we are using it to tweak physical interfaces. If I press this switch, it activates the screen interface to scan.
Next, I will be connecting one of these trackballs (from SparkFun) to the screen interface.