In my first post about my final project I provided photos of a stepper motor, stepper driver, and FPGA development kit.

I will use none of those for my final project. Why? It turns out that getting high resolution rotary encoders for free is very difficult. Instead I shall be using the following parts:

Simple Knob Rotary Encoder

This is a simple rotary encoder which has 24 counts per revolution and reports angular change via quadrature encoding. Quadrature encoding is a very cool method of transmitting the angular change as you can both artificially increase the resolution 4x but also tell the direction of rotation. See this article for details. Specifically read the “Further Description, Including Encoder Waveform” section.

Breadboard and Jumpers

Just a standard breadboard with jumpers.

Arduino Leonardo

The Arduino Leonardo is an updated version of the Arduino Uno. It is less expensive to manufacture and has an updated ATMega microprocessor. I choose this part mainly because it has 4 available external interrupts while the Uno only has 2.

Project Goals
My goal with this project is to produce a virtual etch-a-sketch. I will further extend the etch-a-sketch concept by including velocity data into the drawn lines in some form or another. I could modulate the stroke width, the color, or both.