ABSTRACT
Electronic Digital Message Display Board is an electronic gadget that is capable of displaying length of alphanumeric characters, symbols and any form of representation on a matrix of light emitting diodes (LED) scrolling the characters across the screen for reading the emerging information. This project set out to solve the problem of inadequate clarity, objectiveness and degree of comprehension inherent in paper bill boards. Also, response to the information is further enhanced when the medium employed is attractive and highly inviting, as the case for a moving display. The design and construction of the electronic digital display board consist of some units that make up the whole hardware. Among the units are: Input unit, Controller unit, Display unit and power supply unit as well as the decoder unit. There are some basic electronic components that were being used during the construction, these involve the following: PIC16F877A microcontroller, resistors, capacitors, voltage regulator, crystal oscillator, LEDs, transformer, relays, bridge rectifier, and transistors which had been discussed in chapter two. The drivers unit consists of NPN transistors and 1k resistors thereby, serves as drivers that drive the data which has been transformed to different patterns of display from the data bus of the Chips to the display unit (LED). The project here was tested at various stages to ascertain its workability. Lastly, LED matrix information display is all about the distribution of information in LED 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 LED matrix information display. The advents of microcontroller LED matrix information display have made it easier for us to display information in this format in a unique way.
CHAPTER ONE
INTRODUCTION
1.1 PREAMBLE
The role of information dissemination in the society indeed remains one which cannot be overemphasized. In addition to its vital functions of enlightening, educating, entertaining, and facilitation of commercial activities through advertisement and marketing of goods and services, its use in surveillance and monitoring (security, traffic control etc) and description of places also remains indispensable.
Various means of information dissemination which include broadcasting (radio and television), the internet, newspaper, bill boards, sign posts and neon displays, are employed, the choice of which depends on factors such as the targeted audience, the environment concerned, the purpose, available technology and economy.
However, regardless of the medium employed, of utmost importance is the fulfillment of the purpose for the information dissemination. The information should also be relevant in terms of reaching the intended range of audience with clarity, objectiveness and a good degree of comprehension. Also, response to the information is further enhanced when the medium employed is attractive and highly inviting, as the case for a moving display.
This project work involves the design and construction of scrolling (moving) advert display. A moving message display which could also be referred to as an electronic notice board is an electronic gadget that is capable of displaying lengths of alphanumeric characters, symbols and any form of representation on a matrix (array) of light emitting diodes (LEDs) scrolling the characters across the screen for reading the emerging information. It has an unparallel advantage in drawing people’s attention by prompting them to reflect many times on the scrolling lights automatically displaying either messages of advertisement, place description or greetings at any time of the day. It can be used for both indoor and outdoor purposes. In fact it is the most alluring, unique captivating and attractive means of information dissemination.
The moving message display can be realized in different ways with operational possibilities achievable varying accordingly with the design. This design features a USB keyboard user interface with which the user can input or edit data to be displayed.
1.2 AIM AND OBJECTIVES
Aim
The aim of this project is to design and construct a microcontroller based moving message display.
Objectives
§ To identify the basic components and materials used for the design and construction of a moving message display board.
§ To identify and examine the various models and ways of constructing moving message displays boards.
§ To design and construct a moving message display with the use of a microcontroller with the sole aim of using reduced number of components.
§ Write a program for the operation of the whole unit which will handle the operation of message scrolling and the interrupt handling for the USB keyboard input.
§ To design a power supply unit that will last for 96hours before it is totally discharged and a minimum of 18hours to be fully charged.
§ To test the constructed display unit ensuring that desired features are obtained and that electrical design measures and standards are not compromised.
1.3 SIGNIFICANCE OF STUDY
This project will serve as a means of digging into the technology involved in the use of micro controller and some other basic electronic components such as transistors, resistor, voltage regulator, etc, this will be used in the design and implementation of an electronic digital message display board.
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 manual/analog way of displaying information to the people only attracts few audiences. 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 STUDY
The digital scrolling light advert display would be implemented using light emitting diodes (LED) matrix array. The LED matrix array would be driven by a microcontroller programmed to handle the character/ message display. The choice of the LED matrix array and the use of a microcontroller is made with the aim to ensure that the display unit does not consume much power. Keyboard user interface with which the user can input or edit data to be displayed would be implemented.
1.5 Methodology
To effectively achieve the objective of this project, the following are the methods and procedures that would be adopted:
1. Visit the library and consult the internet on previous works done on digital display of this kind.
2. Design an electronic display system that would:
a. accept, externally via USB port, message to be displayed on the led matrix display
b. include scrolling /moving effects to the advert display,
c. write a firmware (program) for the design, and;
d. Include an interrupt routine based code for message change on user input.
3. Construct an electronic system that would feature the above- listed designs.
4. Test the constructed electronic system to ensure that the above listed objectives are duly met and that the electrical and electronic engineering standards for appliances design are not compromised.
