ii.List of figures 6
Chapter 1. Introduction 7
1.1 Literature survey 8
1.2 Block Diagram 9
1.3 Overview of Project 10
1.4 Overview of Block Diagram 11
Chapter 2. Hardware Design 12
2.1 Interrupter Module 13
2.2 Mechanical Assembly 15
2.3 Power Supply Module 18
Chapter 3. Software Design 19
3.1 Overview of software used 20
3.2 Algorithm 21
3.3 Flow Chart 22
3.4 Pseudo Code 23
Chapter 4. PCB Design 25
4.1 PCB designing steps 25
Chapter 5.Results and Conclusion 26
5.1 Interrupt module testing results 27
5.2 DC motor RPM measurement 28
5.3 Power Supply Testing 28
5.4 Displaying of generated patterns 29
Chapter 6. Appendix 30
6.1 User’s guide 31
6.2 Troubleshooting manual 31
6.3 Source code 32
6.4 reference 54
This project is a special kind of circular LED display. With the help some mechanical assembly, LED count, hardware requirement, and hence overall cost is cut to very affordable price. Also, maintenance and repairing of the display is so easy, that anyone having a little electronics knowledge, can take care of this. All the synchronizing can be implemented through software.
First of its kind, made using the 20-pin 8051 series microcontroller, this project use the principle of Space Multiplexing. This propeller display is mechanically scanned and displays the characters in digital format. Made from scrap it can be used anywhere and everywhere and the most amazing fact about this display is it’s crystal clear display. This display consists of just 8 bright LEDs which are rotated to show the display.
For building this project, requirement is just a small 20 pin microcontroller, a position encoder, and LEDs. This display can show the messages, which will require a whopping 525 LEDs. So hardware and cost minimization is achieved.
(ii) LIST OF FIGURES
Figure no. Name of FigurePage no.
1.BLOCK DIAGRAM 9 2.INTERRUPTER MODULE14
3.OPERATION OF INTERRUPTER15
7.INTERRUPTER MODULE TESTING27
8.VARIOUS DISPLAY PATTERNS29
1.1 Literature survey
1.2 Block Diagram
1.3 Overview of Project
1.1 LITERATURE SURVEY
This project was started with a simple principle which is frequently encountered in our everyday life, which is Persistence of Vision. This phenomenon makes one feel fast moving/changing objects to appear continuous. A television is a common example, in which image is re-scanned every 25 times, thereby appear continuous.
Further, a glowing object if rotated in a circle at fast speed, it shows a continuous circle. By modifying this basic idea, 8 LEDs can be rotated in a circle, showing 8 concentric circles. But if these LEDs are switched at precise intervals, a steady display pattern can be shown.
Existing systems do employ POV principle, but for displaying each pixel, individual LED is used. This results in a huge number of LEDs even for small sized displays. By using a propeller type display, LED count can be kept to a bare minimum. Even 8 LEDs can perform a task of over 525 LEDs.
Applications can find their way into cost effective solutions for large public displays, information systems. It can directly replace Railway station information displays, bus stands and many more places.
1.2 BLOCK DIAGRAM
Fig.1 : block diagram of Propeller LED display
1.3 OVERVIEW OF PROJECT
What is PROPELLER LED DISPLAY???...