CHAPTER ONE 

INTRODUCTION 

  The purpose of this project is to produce a narrative description of the design and construction of a microcontroller based dot matrix 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. 1.1       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 CAFETERIA”           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. 1.2    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 CAFETERIA’ 1.3       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. 1.4     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. 1.5    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.                1.6     BLOCK DIAGRAM OVERVIEW The entire project given as an overview is shown in diagrammatically in Fig 1. Below            
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Fig 1.0: Block Diagram Overview of the project   As the name implies, this project is micro-controller based, hence a micro-controller called AT89c51 is employed to serve the purpose with RAM and some other discrete components that are to be discussed later.  In other to reduce the risk and complications involved in using only discrete components the project is made up some integrated circuits.           Meanwhile, this project, microcontroller based dot matrix advert display system has sub units such as: ·         The mains unit. ·        The power supply unit ·        The switching and timing unit ·        The address generators unit ·        The memory unit/ Micro-controller ·        The drivers unit                                       

    
Fig 1.1 the block diagram of project 1.7       PROJECT REPORT ORGANIZATION          Six chapters were covered in the course of design and development of this project. The chapters and their contents are as follows: Chapter one is the introductory chapter that gives the aim, scope and justification for the project. This part shows the significant and the justification of this project that is the literature review of microcontroller dot matrix advert display system and its components reviewed, also the history of the project and its uses were discussed. Chapter Two is literature review. It deliberates on different related works done by several authors with dates. It also discusses on the limitations of some of these works. In chapter three, I discussed the practical system analysis based on what a microcontroller based dot matrix advert display system will do when fully constructed and installed. Also discussed is the requirement analysis, which is all the information, gathered form a wide research on microcontroller based dot matrix advert display board, data analysis, system design approaches, top-down, bottom-up, choice of design approaches, data flow arrangement and the system flow chart are also discussed. Chapter four deals with the design/preliminary design of how the system will achieve its function, all these are illustrated here in form of circuit diagram to show how the main system is linked to the sub system or the modules. Also discussed here is the user interface design that comprises the input design and the output design. The software design and implementation is also discussed in this chapter. The choices of programming language, soft-hard, and sub-system implementation is also discussed here. In chapter five I discussed the system testing and the appropriate software testing strategy to achieve the expected result and the actual. The performance evolution is also analyzed here. Also discussed is the system testing and integration, how the components were tested. The reference evaluation and cost analysis is also discussed here. Finally the summary of this project is discussed in detail in chapter six. The contributions of the project, achievements, and problems for further enhancement, development and advanced discussions on this topic