# Persistance of Vision

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## Introduction: Persistance of Vision

The original idea for this project came from the brilliant mind of David Bjanes who has many projects in his project queue. The inspiration came when David saw a video of a similar POV display on Youtube.com. We approached Bruce Land, our professor, to discuss whether or not this would actually be a viable project idea. Next, we started brainstorming about the orientation of our POV display. Some ideas we had seen oriented the display on a propeller or circular clock, while others spun the display around a cylinder. We chose to build column style POV display in order to reduce the complexity of mapping a Cartesian coordinate system (found in most rectangular displays) to a polar coordinate system.

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## Step 1: Making Pov

The purpose of this project is to design and to create a persistence of vision (POV) display. This display will allow users to upload an image to be displayed through wireless communication. A persistence of vision (POV) refers to the phenomenon of the human eye in which an afterimage exists for a brief time (10 ms). A POV display exploits this phenomena by spinning a one dimensional row of LED's through a two dimensional space at such a high frequency that a two dimensional display is visible. In our case, we created a cylindrical display by spinning a column of LED's around a central motor shaft (Figure 1). The rotational speed of the LED's is fast enough such that the human eye perceives a two dimensional image.
Figure 1. Hardware setup of POV display. The overall design of this project can be grouped in the following three categories: electrical design, mechanical design, and software design. The most labor intensive portion of this project was the mechanical design. While the electrical schematics and software design appear trivial, integrating the hardware with an adept firmware proved to the biggest challenge of all. Mounting the electrical components onto the mechanical structure - i.e. the spinning arm - was also quite a challenge. As one can foresee, the nature of our mechanical design introduced various safety issues that we also had to take into consideration.

## Step 2: Programing Pov

The original idea for this project came from the brilliant mind of David Bjanes who has many projects in his project queue. The inspiration came when David saw a video of a similar POV display on Youtube.com. We approached Bruce Land, our professor, to discuss whether or not this would actually be a viable project idea. Next, we started brainstorming about the orientation of our POV display. Some ideas we had seen oriented the display on a propeller or circular clock, while others spun the display around a cylinder. We chose to build column style POV display in order to reduce the complexity of mapping a Cartesian coordinate system (found in most rectangular displays) to a polar coordinate system.

Participated in the
Manly Crafts Contest

Participated in the
Supercharged Contest

Participated in the
Workshop Contest

Participated in the
Make It Glow Contest

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