Description
DESIGN AND CONSTRUCTION OF A DIGITAL LED DISPLAY BOARD
BY
…………………………………………………………………………..
JANUARY, 2012.
CERTIFICATION
This is to certify that this work was carried out by:
APPROVED BY:
…………………………………. ……………………
DATE
(SUPERVISOR)
……………………………………. ……………………
DATE
(HEAD OF DEPARTMENT)
…………………………………… ……………………..
(EXTERNAL EXAMINER DATE
ABSTRACT
This project describes a digital bulletin board which is a light emitting diode (LED) based
display system that is used in disseminating information to the general public. The system
comprises of a Peripheral interface controller (PIC) microcontroller chip that has an internal
memory used to store the information to be displayed and several serial to parallel shift
registers. The information on the display is transmitted from a computer system through a
serial port programming tool called the PIC programmer and then stored into the
microcontroller for display operation. The microcontroller is designed to read the stored data
in its internal EEPROM based program memory by following instructions in an assembly
language program. This program is developed on a computer system using the
microcontroller's instruction set. The content of the display can be altered at any time the
need arises simply by typing a new set of information in the assembly program using a text
editor and re-programming the microcontroller with the information that will be shown on
the LED dot matrix display board. Electronic bill board has taken a different facet. Due to
the advancement in data communication, information can now be disseminated with the use
of an electronic bill board that is controlled by a microcontroller chip.
DEDICATION
This project is dedicated to God Almighty who through his infinite mercy has led us to this
joyful end. May his name be glorified in Jesus name Amen.
ACKNOWLEDGEMENT
Our sincere thanks are hereby expressed to our supervisor,
TABLE OF CONTENTS
Title page
Certification
Dedication
Acknowledgement
Abstract
Table of Contents
CHAPTER ONE
1.1 INTRODUCTION
1.2 Aims & Objectives
1.3 Economic Importance
1.4 scope of the project
CHAPTER TWO
LITERATURE REVIEW
2.1 History of LEDs and displays
2.2 Types of displays
2.3 concepts of microcontroller
2.3.1 Structure of PIC microcontroller
2.3.2 Programmers and types of PIC programmers
2.4 Advantages & Disadvantages of computer automation
2.4.1 Computer interfacing
2.4.2 Serial port interfacing – NRZ Protocol
CHAPTER THREE
BLOCK DIAGRAM
3.1 Block diagram description
3.1.1 Hardware components and circuit blocks
3.2 The display – LED circuit wiring
3.3 serial- to – parallel converter
3.4 microcontroller circuit
3.4.1 Important features
3.4.2 Pin diagram- description table
3.5 power supply
3.6 circuit testing & soldering
3.7 Design Specification/consideration
CHAPTER FOUR
SOFTWARE DESIGN & ANALYSIS
4.1 Assembly language programming concept
4.1.1 Overview of MPLAB IDE
4.1.2 Setting up & running a program
4.2 Instruction set description of PIC MCU family
4.3 Assembly code description- flow chart
4.4 Cost analysis
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
5.1 Conclusion
5.2 Recommendation
5.3 Future advancements of the project
Appendix 1 References
2 Circuit diagram
3 Source codes for the microcontroller
1.0 INTRODUCTION
Advancement in digital electronics has drastically narrowed down the cost and has also
saved the energy required in altering the information written on a signboard. It has also
facilitated the speedy change of information from one sort to another without much stress.
This is made possible by means of microcontroller based electronic circuit. The messages are
usually displayed on a screen or an alphanumeric display unit in a dot matrix format
Electronic bulletin boards can be defined in terms of their role as electronic devices
incorporating displays that form the so-called visual man-machine interface. They are
involved in data transmission in a system which can be used in a wide variety of
applications. The display system comprises the microcontroller (PIC16F876X), shift
registers, power supply and LED display board in dot matrix.
1.1 AIMS AND OBJECTIVES
This project is aimed at designing and constructing a digital display board as a way of
disseminating information to the general public and this can be programmed and
reprogrammed up to a thousand times using a remote computer. The overall system if
completed will reduce the cost of operating an information board. The most important of
these achievements is that the display board can be at a remote centre while it is being
programmed with a computer system and this can be applied in highway systems,
advertisement conference centers, university board and any other forms of information
disseminations.
1.2 ECONOMIC IMPORTANCE
The following are the importance of the display board:
1. It gives people direction to certain location/ venues.
2. It eliminates the need of typing and printing of information on paper
3. It is used in advertising products and programmes to the general public.
4. It gives a twenty-four hour display of information as opposed to the static signboards
which are difficult to read at night.
5. It draws the attention of people to its location since it has good aesthetic appearance.
6. It makes it easier for one to send information to the display board using the program
7. It can be used to give hazard or warning signs in the industries.
1.3 SCOPE OF THE PROJECT
The scope of this project covers computer programming used to address the serial port of a
computer system so that data can be transmitted to it. The display system consists of
switching circuit, power supply module, and a dot matrix display unit, embedded with a
microcontroller which consists of stored programs with its programming and reprogramming
ROM & RAM. A microcontroller is a computer on a chip which can be programmed and re-
programmed to control devices.
Thus, this project covers the display of information to the general public using LEDs dot
matrix display board. The design has a high speed capability and attempts to offer the highest
order of flexibility (of the microcontroller) over shadowing the rigidity of the system; it is
highly modularized and thus introduces much convenience for designers.