The project describes a simple, low power, low cost shaft encoder built around a small stepper motor and an ATtiny13 microcontroller. It can be implemented as Jog Dials on portable devices (such as portable mp3 player) and low cost PDAs ; wherein the dial can be used to quickly type in a short message by rotating and choosing appropriate characters. The spindle that needs to be rotated can be mounted on the shaft of the miniature stepper motor. A serial output interface indicates the direction and magnitude of the rotations.
Shaft Encoder Project
Project Firmware, Schematic and Documentation