CONSTRUCTION OF MICROCONTROLLER DOT MATRIX DISPLAY SYSTEM

ABSTRACT
This project is about a microcontroller dot matrix system. This information display system is made in such a way that it can attract attention at any time of the day or night because they system flashes out each of the alphabet or words from left to the right end of the display system. Dot matrix information display is all about the distribution of information and entertainment in dot matrix format, usually including software that allows viewers to interact with text, symbols and images. Most forms of information can be published electronically by way of dot matrix information display, The advent of microcontroller have made it easier for us to display information in this format in a unique way.This system now represents a kind of information board that is now seen along most industrial and commercial parts of the country. Big establishment like banks, oil companies, big hotels etc now used electronic board to pass information to the public. For this reason I embarked on this information display project. The design work consist of mostly LIGHT EMITTING DIODES that display the letters;  TRANSISTORS; RESISTORS; MICRO CONTROLLER; TRANSFORMERS, etc.
 
LIST OF TABLES
List                 Name                        Page
3.0        3-t0-8 decoder/demultiplexer truth table          18
4.0        Mnemonics                              44
4.1        Table of Technical Data for LEDs              53
 

 
LIST OF FIGURES
Fig.                Names                            Page
1.0        Block Diagram overview of the Project                  6
1.1        The Block Diagram of Project                     7
2.0        A Dot Matrix Display                         13
3.0        Block Diagram of Power Supply Unit                 15
3.1        Transformer and its output                     16
3.2        Circuit diagram of a full wave rectifier             16
3.3        Circuit diagram of a power supply + filter             17
3.4        Symbol of 7805 Regulator                     18
3.5        Voltage Regulator and Output wave form of regulated
Voltage                                 18
3.6        Symbol of npn and pnp transistors                 21
3.7        Microcontroller Pin Configuration                 30
3.8        System Reset Circuit                         34
3.9        Microcontroller with Crystal Oscillator             36
3.10        Circuit Diagram (1) of Microcontroller based Dot Matrix
        Information Display Board                     49
4.0        Internal Block diagram of Microcontroller AT89C51    52
4.1        System Flow Chart                        60


 
TABLE OF CONTENTS
Title page                                         i
Certification                                     ii
Approval page                                     iii
Dedication                                         iv
Acknowledgements                                 v
Abstract                                         vi
List of Tables                                     vii
Figure of Figures                                    viii
Table of Contents                                     ix
CHAPTER ONE: INTRODUCTION
1.1    Background                                     1
1.2    Objective of the Project Design                     2
1.3    Preamble                                     2
1.4    Justification of the Project                         4
1.5    Scope of the Project                             5
1.6    Constraints                                     5
1.7    Block Diagram Overview                         6
1.8    Project Report Organization                         7
CHAPTER TWO: LITERATURE REVIEW
2.1    Origin/History of the Project                         9
2.2    Technology of Dot Matrix Display                    10
2.2.1 Optics and Lighting                             10
2.3    Uses of the Project                             12
2.4    Advantages of the Design                         12
2.5    Types of Dot Matrix Display                         13
CHAPTER THREE: DESIGN PROCESS AND IMPLEMENTATION
3.1    The Main Unit                                 14
3.2    The Power Supply Unit                             14
3.2.1 Transformer                                     15
3.2.2 Rectifiers                                     16
3.2.3 Filters                                         16
3.2.4  Regulator                                     17
3.3 The address generator’s Unit                             18
3.4 The Memory Unit/Microcontroller                         19
3.4.1 Description                                     20
3.5    The Drivers Unit                                 20
3.5.1 Transistor                                    21
3.5.2 Light Emitting Diodes (LEDs)                        21
3.5.3 Sizes, Shapes and Viewing Angles of LEDs                22
3.6    Design Process                                 23
3.7    Preliminaries of the Design                         25
3.7.1 Making a LED Blink with AT89C51 Microcontroller             25
3.8    Detail of Design                                 27
3.8.1 Microcontroller Pin Descriptions                         28
3.8.2 System Reset                                     34
3.8.3 Oscillator Characteristics                             35
3.9    Software Design                                 36
3.9.1 Software Development                             37
3.10 Development Process                                 39
3.11    Program Entry and Editing                             39
3.12 Assembling and Linking                             39
3.13    System Control Program Steps                         40
3.14    Software for the Programmer                         41
3.15    Soft to hard Design                                45
3.16    Flash or Eprom Programmer                        46
3.17 Using a Personal Computer to Program the AT89C51            47
CHAPTER FOUR: METHODOLOGY
4.1    Information Gathering                             51
4.2    Data Analysis                                 52
4.2.1 Reading a Table of Technical Data for LEDs                53
4.2.2 Calculating the LED Resistor  Value                     54
4.2.3 Calculating the Load Current of the Rectifier                 55
4.3     System Design Approaches                             57
4.3.1 To-Down                                    57
4.3.2 Bottom-Up                                    57
4.4  Choice of Design Approaches                         58
4.5  Data Flow Arrangement                             59
4.6   System Flowchart                                 60
CHAPTER FIVE: SUMMARY AND CONCLUSION
5.1    Summary of Achievement                             61
5.2    Problems Encountered and Solution                     61
5.3    Suggestions for Further Improvement                     63
5.4    Conclusion                                     63
    References                                     64
    Appendix 1: Acronyms and Their meanings                 65
CHAPTER ONE
INTRODUCTION
1.1    Background
  The purpose of this project is to produce a narrative description of the design and construction of a microcontroller based on voltage display dot matrix and advert display. Firstly computer aided design is the modeling of physical system on Computers allowing both interactive and automatic analysis of design variant and the expression of design in a form suitable for manufacturing. This follows by explaining the microcontroller based dot matrix advert display as a device which is fast gaining wide acceptance and application in the present days due to its ability to provide a very high precision timing. The dot matrix advert display can be describe as an electro-mechanical  system for processing information in which the information is represented by physical quantities, which are so constrained to take only discrete values that can be referred to as binary signals.
In this design we have implored the use of both hardware and software to bring about the entire project. The hardware components are solely coordinated by the AT89S51 micro controller chip while the C- programming language is used to program the chip.


1.2    Objective of the Project Design
Depending on ones intention, microcontroller based dot matrix advert display system have many aims and objectives.
For instance, this one in particular aims at displaying a moveable coded letters that says ‘UNIVERSITY ESUT”
    Also microcontroller based dot matrix advert display system can be used to control the traffic misunderstanding among motorists especially in junctions. This is achieved by displaying stop, get ready, or move. Some traffic control electronic system displays symbols or color that represents the stated commands above
Moreover, microcontroller based dot matrix advert display system is used in electronic scoreboard during football matches to display when a goal is scored, also to display the name of that player who scored the goal. Above all, this system has contributed a lot in boosting advertisement.
1.3    Preamble
Micro controller programmable Dot matrix information display system, is a system electronically designed and constructed, that is used to display different information to the view of the masses. The information to be displayed could be diagrams, symbols, letters, colors, numbers, codes, etc depending on what is needed at a particular place and time. This without doubt, has made life easier for the people in different ways; however micro-controller, which is the heart of this system, can be described thus: A micro controller is a computer. All computers, whether we are talking about a personal desktop computer you are using is a general – purpose computer that can run any of thousands of programs. Micron-controllers are special purpose computers. Micro controllers do one thing well. There are a number of other common characteristics that define micro controllers. If a computer matches a majority of these characteristics, then you can call it a micro controller,
1)    Micro controllers are embedded inside some other device (often a consumer product) so that they can control the features or actions of the product. Another name for a micro controller, therefore, is embedded controller    
2)    Micro controllers are dedicated to one task and run one specific program. The program is stored in ROM (read – only memory) and generally does not change. Micro controllers are often low power devices. A desktop computer is almost always plugged into a wall socket and mighty consumes 50 watts of electricity. A battery-operated micro controller might consume 50 milliwatts.
3)    A micro controller has a dedicated input device and often (but not always) has a small LED or LCD display for output. A micro controller also takes input from the device it is controlling and controls the device. Meanwhile the use of a micro-controller to implement an electronic display system design made up of LEDs connected in common cathode matrix form is referred to as micro-controller based programmable dot matrix information display system. This project design is a welcome compliment that displays ‘UNIVERSITY ESUT’
1.4    Justification of the Project
    Due to the various problems encountered in the manual/analog design and construction of signposts for advertisement, there is every need for an automated electronic display system that will solve this problem. This will ensure that viewers get the adequate information that is displayed in good and attractive colors. The though the manual/analog way of displaying information to the view of the people is still targeted viewer are attracted. The height in which advertisement in Nigeria have attained will be maintained if some of its design/construction operation is computerized (Micro controller based information display) especially the one’s that has to do with bigger companies. This will also maintain the good relationship between the company and its numerous customers.
1.5     Scope of the Project
This project can serve in any aspect of life this project (microcontroller based dot matrix advert display) is based on a computer aided design. .
 In the implementation of this project, the scopes that I shall concentrate more on are:  the architecture of the microcontroller port interface, multiplexing the data port control sequence and algorithm of the traffic light. The features of the
AT89S51 were exploited to achieve the desired sequence of operation of this project.
1.6    Constraints
One of the obvious constraints I had in the course of this project was the scarcity of sometimes outright unavailability of some of the required components in the markets. Since scarcity is followed by a hike in price, when such components were even found, they were out rightly expensive. Another major constraint I had was time constraints. I had a relatively short time to source out materials from net, libraries, etc, fully understand the underlying principles and come up with a design that would work. As a result, I had to forgo pleasure and even leisure in order to achieve this.

1.7     Block Diagram Overview
The entire project given as an overview is shown in diagrammatically in Fig 1. Below