Servo Magazine (February 2009)
A Practical Quadrature Encoder
Building projects involving electronics and robotics is much easier today than in the past because many of the commonly needed subsystems are available as ready-to-use modules (we will call them HMs [helper modules]). For example, there are HMs for controlling nearly any type of motor (DC, stepper, servo) and HMs to collect environmental data (humidity, temperature, distance to objects). You can find switching power supplies, battery chargers, Bluetooth modems, and dozens more just by looking...