Now prototyping in earnest. I realized that older computer mice knew whether they were moving backwards or forwards. Perhaps I could use an optical encoder wheel. Time was running out, so I started working with IR LEDs and photo-detectors. I’m not sure if I have photo-diodes or photo-transistors. The parts I have are from high school — and completely unlabeled. In order to figure out the polarity of the devices, I examine the lens of the LEDs using the digital camera, which allows me to “see” infrared light.
