Optical Encoder from scratch

Overview

This Project is a subset of my Braille Board startup. Part of the startup requires numerous dc motors, so the need for cheap feedback that fits my specific use case is necessary: Low Notch counts per rotation, very cheap, and simple

How it works

To encode position, a beam of IR Light is interrupted. to detect the light, a phototransistor is used. A photo transistor amplifies the change to a measurable voltage, but has very slow rise time. So, the signal is sped up using a comparator circuit.

Results

In the time I've worked on it, I was able to consistently count interrupts at low speeds, improvements are necessary to make the design more robust.