Rotating Led Display

Rotating Light Emitting Diodes (LED) Display: Based on the principle of the

persistence of vision

Made By:

Hassan Saeed Al-Qadheeb

Under Supervision and Guidance of:

Dr. Hesham Enshasy

January 2013

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Abstract

This report introduces the reader how to build a virtual display consisting of only

seven rotating light emitting diodes (LED’s) to show any word or shape on it. It

will also give the reader enough information to start using microcontrollers and

also provide instructions to build and program the rotating display.

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Contents

1- Introduction ……………………………………………………… Page 4

2- Objectives ………………………………………………………… Page 5

3- Methodologies ……………………………………………………. Page 5

 Block Diagram ……………………………………………….. Page 5

 Hardware Description ……………………………………….. Page 6

4-Design …………………..………………………………………….. Page 7

5-Programming the Rotating Display ………………...……………. Page 9

6-Testing the Rotating Display ……………………………………… Page 13

7- References …………………………………...…………………….. Page 15

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1-Introduction

This report describes the idea of a rotating light emitting diode (LED)

display, consisting of only seven LED’s. The principle is that the LED’s are placed

on a rotating vertical arm , and are switched on and off at exactly the right times to

convince the eye that you are looking at the seven by 35 matrix of LED’s forming

a letter. The LED’s are switched on and off by the microcontroller that is rotating

along with the LED’s. A CPU used for rotating the microcontroller and the LED’s.

This project was started with a simple which is Persistence of Vision (POV).

This phenomenon makes eyes feel fast moving objects to appear continuous (as an

example see figure 1).

Figure 1: Persistence of Vision, Coins example

Also the television is a very common example; in which image is rescanned every fraction of second, thereby appear continuous. Further, a glowing

objects if rotated in a circle at fast speed, it shows a continuous circle. By...