Persistence of Vision Wand

Introduction

Persistence of vision is the optical illusion that happens when human visual perception continues after a object ceases to appear. This project was assigned to me in ECE 341 - Junior Design. The goal was to create a persistence of vision system using a microcontroller that could display a word when swung back and forth. This project was one of two "accelerated" three week group projects which I completed during this class.

Requirements

  • The wand will display a 7+ letter word.
  • The word should be visible when swung back and forth 3 times in a moderately dark room.
  • Design

    Block Diagram>

    POV Wand Block Diagram

    Interface Definitions

    outside_system_env
  • swinging motion, back and forth
  • travels about 12” to 24" per swing
  • rate of 3-5 swings per second
  • leds_outside_usr
  • Displays character of at least 3x5 pixels per character
  • Words of at least 5 characters
  • 9 out of 10 people can read the displayed word
  • Schematic

    POV Wand Schematic

    Final Thoughts

    Considering that this was the first project that I participated in Junior Design I think that it went well and contributed to a lot of learning experiences. Technically speaking, it was not a particularly difficult project, but it was definitely a crash course in getting a project together and working in a short amount of time which is a skill in itself.