Above is the speed sensor prototype and its schematic. The infrared LED (TSMF1020) and photo-transistor (TEMT2020) will be reading from a rotating disk colored black and white. The photo-transistor will detect the highest levels of infrared light when it sees the white part of the disk, which will lead to a higher voltage drop across the 100 ohm resistor.
The board will be tested to find the optimum system geometry and the system's sensing limitations (e.g. max velocity).
