TO THE DEPARTMENT OF ELECTRICAL/ELECTRONICS ENGINEERING, SCHOOL, INSTITUTE OF MANAGEMENT AND TECHNOLOGY (I.M.T) ENUGU
ABSTRACT
As the name of the project implies “Electronic dot
matrix display board”, is an electronics system that is used to display
specific information to the public. It displays only alpha-numeric characters
in a constantly moving format.
This project presents the design and
construction of a microprocessor based electronic dot matrix display. This is
achieved with the use of an active component known as ATMEL 8952, where all the
coded digits and letters in hyxadecimal (BCD codes) are programmed for display.
The light emitting diodes (LEDs) are
used extensively for the actual display of characters by their on and off
states that are controlled by switching transistors.
The power supply unit consists of a
step down transformer, rectifying diodes and backup power supply units.
The project also consists of a display
module where the information from the micro controller finally displays itself
for view. The display module is made up of II characters per page, each
containing a 10 x 14 dot matrix array. This array is achieved with a red light
emitting diodes already made ones.
TABLE OF CONTENTS
COVER PAGE PAGES
TITLE PAGE i
APPROVAL PAGE ii
DEDICATION iii
ACKNOWLEDGMENT iv
ABSTRACT vi
TABLE OF CONTENTS vii
CHAPTER ONE 1
1.0
Introduction 1
1.1
Aim 2
1.2
Limitation 3
CHAPTER TWO 4
2.0
Literature review 4
2.1
Review 4
2.2
Important concept 6
2.3
Component used
discuss 7
CHAPTER THREE 28
3.0
System operation 28
3.1
Block
diagram/system operation 28
3.2
CCT diagram and
CCT operation 35
CHAPTER FOUR 36
4.0
System
construction and system packaging 36
4.1
Component
sourcing 36
4.2
CCT
layout/prototyping 39
4.3
Arrangement 40
4.4
Packaging 40
CHAPTER FIVE 42
5.0
System testing
& result 42
5.1
Continuity
testing 42
5.2
Voltage testing 42
5.3
Result 43
CHAPTER
SIX 44
6.0
Conclusion &
recommendation 44
6.1
Conclusion 44
6.2
Recommendation 45
References to source to work. 46
CHAPTER ONE
1.0
INTRODUCTION
In
today’s world where technology has Come of a certain age, it will be oddly Out
of place to see that information that are meant for public consumption, are
Presented or displayed in a manner that is Rather obsolete and unsatisfactory,
hence the need for a better and a more attractive System for displaying information
to the public.
The self programmable dot matrix moving display is an
electronic system that displays alpha-numeric characters in a moving manner on
a flat plane screen with the use of LEDs that are arranged in a fixed dot
matrix format. The on and off states of the LEDs are controlled by a
microprocessor and some other ICs in combination with a transistor as s switch
device. In the
sense
that the message being displayed can be changed by erasing and reprogramming in
the new massage from the computer.
The project can be classified into hardware and
software units. The hardware comprises of:
(i) The power supply unit.
(ii) The screen unit.
(iii) The microprocessor unit.
(iv) Demultiplexer.
1.1
AIMS AND OBJECTIVES
From the preliminary investigation prior To designing
this moving massage self programmable electronic display board, we discovered
the importance and need for a system such as this in the society.We also found
out that a very large number of establishments do not have its kind due to the
high cost and complevity associated with the digital display board,as earlier
highlighted.
The
major aims of this project are thus:
1. To
implement a circuit whose component are readily available in the local market.
2. To
design a cost effective electronic moving massage that would be affordable to
the users.
3. To make usage and operation of an
electronic
Displayer less difficult, by the use of a Micro
controller universal boner and computer
4. To
implement an open module architecture that can be easily upgraded to suit the
Specification of producers and manufacturers. We hope
that after going through this work, one should have a better understanding or
the basic principles of the self Programmable electronic display board.
1.2
LIMITATIONS
This
project is not a new technology or invention of design, but rather it is more
of a prototype of an already existing design
It
would display alpha-numeric characters only. It does not have the capacity to
display graphic pictures, animation of any kind or motion pictures (video).It
does not also have the capacity for sound production.
CHAPTER TWO
2.0
LITERATURE REVIEW
2.1
REVIEW
The invention of semi-conductor devices such as
diodes, transistors and integrated circuits was the key invention that
established electronics as a field and also revolutionalized the world of
information processing and control. A three man team at bell laboratories
invented the transistor in the form of semi-conductor devices. This particular
invention heads to the invention or other device including the integrated
circuits (ICs).
It is the technology of semi-conductor transistor
control integrated circuit and J Newman computer theory that gave rise to set
of microprocessor came in the form of a 4-bit microprocessor until 1986, when
the 8-bit microprocessor took the lead. However the bit count has risen to 32
bit.
A
microprocessor is a computer personal on
a microchip. It is sometimes called logic chip. A microprocessor is the
chief component of all personal computers
and most work stations, it controls the logic of almost all the digital
devices, there are three basic characteristics a microprocessor has as to
compare with other chips.
The
characteristics are thus
i.
Instruction set
the set of instruction that the microprocessor can execute.
ii.
Bandwidth: The number of bits processes in single
instruction
iii.
Clock speed: Given in mega hetz (MH). The clock speed
determines how many instruction that would be executed per second.
In all cases, the higher the value, the more powerful
the CPU. For example a 32-bit micro-processor that runs at 50mhz is more
powerful than a 16-bit microprocessor that runs at 25mhz.
This design of a self programmable electronic digital
display band is duplicate of the technology of the ATMEL 8051 micro-processor.
The ATMEL 8051 micro-processor can not work or function alone without an
interface from an external demultiplexer 74154 – PNP transistor in some
applications. Hence the 8051 card, this interface can not be achieved without
involving three ports of the 8051 (i.e. Port 0, 1 and 2) so that the
transistors which control the switching of the light emitting diodes (LEDs).
ATMEL
8952 microprocessor with inbuilt ROM (through an EEPROM) switch made it
possible for us to make use of the 3 port of the micro processor 8952 as thus.
1.
Port 0 for the strobe
inputs of demultiplexer
2.
Port 1 for the
switching transistors
3.
Port 2 for the
select input of the demultiplexer.
2.2
IMPORTANT CONCEPT
2.2.1
FEATURES AND ECONOMIC IMPORTANCE
In this project there are a lot of features and
characters that makes it to be a unique one. One of those features is its
flexibility in terms of its operation and application also, the system is a 20
bust one, in terms of its message, capacity and expandability.
The display screen is composed of a
linear array of light emitting diodes (LEDs) that are arranged in 10 x 14 dot
matrix format as each memory location is addressed, the LEDs under the message.
Messages are programmed (code) in C level language.
The importance of the self programmable electronic
display board lies in its various applications. It can be applied in many ways
of which the ultimate goal is to pass information and communicate to the
general public and get them informed although the project might cost some money
to acquire but it is our innermost hope that as people begin to appreciate this
system, the market prospect will become encouraging and the price be further
reduced, as it is always with new technology.
2.3
COMPONENT USED DISCUSS
2.4
THE ATMEL 8952 MICROCONTROLLER
The AT89S52 is a low-power, high performance Cmos
8-bit device is manufactured using ATMEL’s high-density non-volatile memory
technology and is compatible with the industry standard 8051 and 8052
instruction set and pin out the on-chip flash allows the program memory to be
reprogrammed in-system or by a conventional non-volatile memory programmed by
combining a versatile 8-bit CPU with flash on monolithic chip, the ATMEL
AT89S52 is a powerful micro computer that provides a highly flexible and cost –
effective solution to many embedded control applications.
The word micro suggests that the
device is very small and controller suggests that the device can be used to
control objects, processes and events you can find micro controller in all
kinds of gadgets today. Any device that measures, controls, stores, calculates or
displays information is a candidate of micro controller. The 89S52 provides
belong to the family of chip available in NMOS and CMOS versions.
The
AT89S52 provides the following standard features 8k bytes of flash, 256bytes of
RAM, 32 I/O lines. Three 16-bit timer/counter, a six vector two-level interrupt
architecture, a full duplex serial port on – chip oscillator and circuiting. In
addition the 8952 are designed with static logic for operation down to zero
frequency and supports two software selectable power saving modes. The idle
mode stops CPU while allowing the RAM, timer/counters, serial ports and
interrupt system to continue functioning the power – down modes saves the RAM
contents but freezes the next hardware reset. [II].
Fig. 2.1 pin out of Atmel
8952 micro controller
2.3.1.1
ELEMENTS OF THE ATMEL 8952 MICRO CONTROLLER
The CPU (central processing unit). Executes program
instructions types of instructions include arithmetic, logic, and data transfer
electera. An external crystal provides a timing reference for clocking the CPU.
Rom (read only memory). This is the read only memory
that is programmed into the chip during the manufacturing process. It holds the
main program in its different locations.
RAM (random access memory). This is where the device
stores information for temporary use. The CPU can write to RAM as well as read
from it. Any information stored in the ROM is lost when power is removed from
the chip.
The 8952 have 128 bytes of RAM. I/O (input/output)
ports. This part enable the 8952 to read and write external memory and other
components, the 8952 have four 8-bit I/O ports (port 3), which are effectively
used. It does not have any external memory to write or read from since pin 31
is connected high.
Fig. 2.2 Block diagram of 8952
2.3.1.2
PRINCIPLES OF 8952 MICROPROCESSOR
8952 is a single – chip computer, it has internal 8k
bytes ROM and 128 bytes RAM in-built to hold codes at unique location hence its
ROM is used for permanent storage of programs, while the RAM is a volatile
storage device which losses information. It is holding once power is removed
from the system. For system for the 8952 to access internal memory pin 31
connected high. The 8952 access code memory when it executes an C language,
pure hex file program or subroutine code memory is intended for programs that
have been previously programmed into ROM hence code and date memory can be
combined in a single area, making WR control (write operation) and PSEN and RD
(read operation) are logically ANDED to create a signal that is active when the
program execution from the beginning i.e. at ooooh in code memory finally the
chip has two pins for connecting to a + 5 volts power supply (VCC) and ground
(VSS).
2.3.2
THE 4 – TO – 16 LINE DECODER (74LS154)
The 74ls154 can also be regarded as demultiplexer. It
has four inputs A, B, C and D, which generate sixteen active – low output Y0 –
to Y15. There are two additional inputs STROBE A and STROBE B through which
data goes into the decoder they are both active low.
Fig. 2.3 pin out for 4-16 line decoder/multiplexer
A decoder is a logic circuit that
accepts a set of inputs that represent binary number and activates only the
output that corresponds to that input number. In other words, a decoder
circuits looks at its inputs determine which binary number is present there and
activate while all other outputs remains inactive.
A demultiplexer takes single input
and distribute it over several outputs.
Fig. 2.4 diagram of a general demultiplexer
The large arrows for input and
output can represent one or more lines. The select input code determines to
which output the DATA input will be transmitted. In other words, the
demultiplexer takes one input data and selectively distribute it to 1 of N
output channel just like a multi-position switch.
Select
code output
S1 S2 S3 S4 015
014 013 012
011 010 09 08 07 06 05 04 03 02 01
00
0 0
0 0 1
1 1 1
1 1 1 1 1
1 1 1
1 1 1 0
0 0
0 1 1
1 1 1
1 1 1 1 1
1 1 1
1 1 0 1
0 0 1 0
1 1 1
1 1 1
1 1 1
1 1 1
1 0 1 1
0 0 1 1
1 1 1
1 1 1
1 1 1
1 1 1 0 1 1 1
0 1
0 0 1
1 1 1
1 1 1 1 1 1
1 0 1
1 1 1
0 1
0 1 1
1 1 1
1 1 1 1 1
1 0 1
1 1 1 1
0 1
1 0 1
1 1 1
1 1 1 1 1
0 1 1
1 1 1 1
0 1
1 1 1
1 1 1
1 1 1 1 0 1
1 1 1
1 1 1
1 0
0 0 1
1 1 1
1 1 1 0 1
1 1 1
1 1 1 1
1 0
0 1 1
1 1 1
1 1 0 1 1
1 1 1
1 1 1 1
1 0
1 0 1
1 1 1
1 0 1 1 1 1 1
1 1 1
1 1
1 0
1 1 1
1 1 1
0 1 1 1 1
1 1 1
1 1 1 1
1 1
0 0 1
1 1 0
1 1 1 1 1
1 1 1
1 1 1 1
1 1
0 1 1
1 0 1
1 1 1 1 1 1 1
1 1 1
1 1
1 1
1 0 1
0 1 1
1 1 1 1 1
1 1 1
1 1 1 1
1 1
1 1 0
1 1 1
1 1 1 1 1
1 1 1
1 1 1 1
2.3.3. REGULATOR
This
is a device that holds the load voltage constant, even when there is a
variation in the input voltage source. The regulator 7805 is a three terminal
voltage regulator. For most non-critical application, the choice for regulator
is the simple three terminal types. It has only three connections (input, GND
and output) and it is factory trimmed to provide a fixed output. The typical of
this type is the series 78xx regulator that provides fixed regulated voltage
from 05 to 24v. the best two digits
represented
here by xx specify the output voltage example if this series is 7805, 7806,
7812 etc. and available in an IC chip.
Fig.
2.5 pin out of 87805IC Regulator
The
unrelegulated voltage should be several voltages higher than the desired output
voltage which is 5 voltages for this project. Also it has a maximum load
current if IA.
2.3.4 TRANSISTORS
These are electronics components
made of semi conductor materials and used to amplify a signal. They can be used
as a switch, an inverter and amplifier in the circuit they are fixed. A
transistor is made up of the base, emitter and collector. This material is
manufacturer as PNP or NPN. Which determines the way current flows in it. There
are two main families of transistor, bipolar and field effect transistors.
Switching transistors are designed to be operated fully ON or OFF. These are
called small signal and switching transistors. The three layers of a bipolar
transistor are the emitter base and collector. The base is very thin and fewer
doping atoms than the emitter and collector therefore, a very small emitter –
base current will cause a much larger emitter – collector current to flow.
Fig. 2.6 NPN AND PROP TRANSISTORS
E(emitter)
– it is more heavily doped than any of the other regions because its main
function is to supply majority charge carrier (i.e. electrons or holes) to the
base.
B
(base) – it forms the middle section of the transistor. It is very thin as
compared to either the emitter or collector and is lightly doped.
C
(collector) – it is main function is to collect majority charge carrier coming
from the emitter and passing through the base in most transistor, collector
region is made physically larger than the emitter region because it has to
dissipate much greater power.
How
bipolar transistor are used for switching when the base of NPN transistor is
grounded (0 volts), no current flows from the emitter to the collector (the
transistor is “off”), if the base is forward-based by at least 0 6volts, a
current will flow from the emitter to the collector (the transistor is “ON”)
when operated in only these modes, the transistor function as a switch.
2.3.5
DIODES
Diodes in its simplest from are a
two terminal active, and non-linear device used in controlling voltage and
current in a circuit. In most cases, diodes allows current to flow in one
direction but not the reverse such device include values that contain two
electrodes (anode and cathode). A diode is simple a P-N junction current flows
across the junction when it is forward biased.
Fig. 2.7 A diode symbol
2.3.6
LIGHT EMITTING DIODE (LED)
The
increasing used of digital display in watches, electronics billboards,
calculators and forms of instrumentation has contributed to the current
extensive interest in structures that will emit light – when properly used
properly used the two types in common use today to perform this function are
the light emitting diode (LED) and liquid crystal display (LCD).
As
the name implies the light emitting diode (LED) is a diode that will give off
visible light when it is energized. In any forward – biased P-N junction, there
is within the structure and very close to the junction a recombination of holes
and electrons.
Fig.
2.8 A symbol of light emitting diode
The processor of giving off light by
applying an electrical source of energy is called electro luminescence LED
display are available today in many different sizes and shapes numbers and
alphabets (letters) can be created by segment LEDs are presently available in
red, green, yellow, orange and white. In general LCDs operates at voltage
levels from 1.7 to 3.3v, which makes them completely compatible with solid –
state circuit.
2.3.7
CRYSTAL OSCILLATORS
This uses a piece of quartz that is cut and polished
to vibrated at a certain frequency, crystal oscillator is a piezoeletronic (a
strain generates a voltage and vice versa). The 8952 micro controller has an on
– chip oscillator, which must be run by an external clock signal. A quartz
crystal is configured into an oscillator with capacitors to provide the clock
signal. A quartz crystal emits pulse at a fixed frequency when energy is
applied to it.
Fig. 2.9 A symbol of crystal oscillator
The 8952 use the clock signal provide by the crystal to
synchronize its operations. The 8952 operate using what are called “machine
cycles”. A single machine cycle is the minimum amount of time in which a single
8952 instruction can be executed. A machine cycle is 12 pulses of the crystal.
A 6mhz crystal was used in this work. The number of instructions per second the
8952 will perform is then
16000000
=
12
The quartz crystal is connected cmos input XTAL (pin 19)
of the 8952 micro controller. Two capacitors. 30pf each are connected to the
crystal to make it impossible for frequencies other than that generated by the
crystal to penetrate the 8952
Fig.
2.10 An equivalent CCT of crystal oscillator
2.3.8
RESISTORS
Resistor
is a passive component. It is essential to the function of almost every
electrical circuit. It provides a means of controlling the current and for a
voltage presents in the circuit it is fixed. Resistor is a component that
opposes or restricts the flow of electrons (electricity) through it or
otherwise shows electrical resistance. An ideal resistor obey ohm’s law V= IR
that is the voltage across a resistance
is directly proportional to the current through it. Resistance being constant
of proportionality. Where I is in Amperes. (A), V is in volts (v) and R in ohms
(Ω). there are mainly two of resistors (a) fixed value resistors (a) variable
type resistor.
Fig. 2.11
Diagram and symbol of resistor
2.3.9
CAPACITOR
Capacitor
of various types are used in electronic circuit for storing charges as element
of frequency selective circuit and filter, for compling A.C signals from one
circuit to another and for shunting unwanted signal to ground capacitors can be
divided broadly into two types: those that have a solid electric of ceramics or
polymer and those that have a thin metal oxide film as dielectric. They are
called non- electrolytic capacitors respectively.
Non-electrolytic
capacitors – non electrolytic capacitors used in electronic engineering
projects fall into many groups such as Mica, ceramic, and polymer film etc.
Electrolytic
capacitors – they are used in circuit operation requiring a large value of
capacitance, such as power supply circuit where they find use as reserviour
capacitor, low frequency filter, and timing circuits with long time constant.
In
this project work, the capacitors find their way in filter resonant, timing and
storing charges. Both electrolytic and non-electrolytic capacitors were used in
this project design.
Fig. 2.12
2.3.10
TRANSFORMER
Transformer
are widely available in an electrical configurations are designed for operation
at a specify frequency. It is a device by means of which electric power in one
circuit is transformed into electric. It can raise or lower the voltage in a
circuit but a corresponding decrease or increase in current. A transformer
consists of two closely coupled coils. An A.C voltage applied to the primary
appears across the secondary, with the voltage multiplication proportional to
the firm ratio of the transformer and a current inversely proportional to turn
ratio.
Transformers are of many of types that include:
the automatic transformer or autotransformer, the double wound transformer, the
variable transformer e.t.c.
Given
by E1 = N1
E2
N2
Transformer current equation
is given
By E1 = I2
E2 = I1
Transformer is also a major
class of coil having two or more windings usually wrapped around a common core
made from terminated.
Soft iron sheets, which help
in the reduction of eddy current.
Fig. 2.13 A simple voltage transformer
CHAPTER THREE
3.0
SYSTEM OPERATION
3.1
BLOCK DIAGRAM/SYSTEM OPERATION
Fig. 3.1 Block diagram of the
self – programmable electronics advertisement board.
This
is the basic voltage input source of the design. It consists of the
transformer, the rectifier, the smoothing capacitor and the voltage regulator.
A step down transformer was used to step down the 220v supply by power holdings
to lower voltage of about 12 volts.
3.1.1.1
A BRIDGE RECTIFIER CIRCUIT
A
device is required to change 12 volts A.C to a publishing D.C to achieve this,
a highly bridge network is ideal for this purpose. The rectifier circuit is
made up of four diodes connected in the bridge configuration and is labeled D1,
D2, D3 and D4. The four diodes are used to achieve a full wake rectification.
In the circuit during positive half cycle D1 AND D3 conducts while during
negative half cycle D2 and D4 conducts thereby producing a full wave rectified
voltage.
Fig.
A bridge rectifier circuit with a filter capacitor
3.1.1.2
FILTER CAPACITOR
A
voltage regulator is needed to regulate the 12 volts D.C to a constant or fixed
voltage at the output according to the voltage required by the load for proper
functioning. The voltage regulator used is the three terminal voltage regulators
7805 belonging to the fixed regulated voltage of 5 volts at the output and
which is supplied to all the VCC in the circuit.
Fig.3.3 A diagram of regulated power supply
3.1.1.3
BACK-UP POWER
SUPPLY
The
back-up power supply is just a sub-circuit that is connected to the
micro-controller so that whenever there is a power failure, the in-built RAM
(random access memory) will retain its information. This circuit comprises of a
9volts battery, 7805 voltage regulator and an LED (light emitting diode) and a
battery clip. The battery clip is used to connect the 9volts battery to the
7805 at the output, which is connected to the VCC 9pin 40) of the
micro-controller. This regulated voltage is capable of keeping the
micro-controller in the “ON” state that its RAM will not lose its information
when there is power failure.
Fig. 3.4 A diagram of a
back-up power supply
3.1.2
DEMULTIPLEXER
The
display circuit has about 110 columns of lines that needed to be activated one
after the other, but the total output terminal from the micro-controller is 32
in number, and 8 out of it will be used to supply the information on remaining
24 which will not be enough to activate the lines, there this called for a need
to add demultiplexer a type that uses 4 lines to produce 16 lines.
3.1.3
8952 MICRO-CONTROLLER CARD
The
8952 card is the major circuit of the design. It is made up of ROM, RAM and CPU
etc. it has register memory locations where the software that run the system is
contained. It has four standard ports (port 0-3) and all the ports can be used
unlike the INTEL 8051 micro-controller which only two of its ports can be used
to interface the processor to an external memory device usually EPROM through a
latch (74LS374). This makes it easier such a complex design where by port 2
&3 are connected to the demultiplexers respectively and port 0 is connected
to the transistors to the display board. The serial number of the demultiplexer
used is 74LS154.
Fig. 3.5 The arrangement of
LEDs in 10 x 14 Dot matrix
This is the final module where the information from the
micro-controller finally displays itself for view. The display module is made
up of eleven character is containing 10 x 14 dot matrix array. This array is
achieved with a red light emitting diodes (LEDs). In each column the positive
pins are connected together through out the while in each row are connected to
the demultiplexer 74LS154.
Note that in the demultiplex emitting diodes (LEDs). In
each column the positive pins are connected together through out the while in
each row are connected to the demultiplexer 74LS154.
Note that in the switching, each of the demultiplexer is
responsible for switching, each of the demultiplexer is responsible for the
information that is displayed on a given 10 x 14 dot matrix screen while each
of transistor is responsible for switching all the corresponding columns of the
screen. All these sections/modules work as a group through individual to
enhance the overall design.
The maximum current needed by the
LEDs = 25MA (for data sheet). The voltage entering the LEDs from the
transistors is 5v. The transistor that may in turn damage it, a resistor of the
value 1000Ω is used as a biasing resistor.
The LED current can be calculated by
the formular
V =
IR (ohm’s law).
Where
R = 220Ω V = 5
So that
I = V 5 =
R 1000
This
current still enough to make the LED show even brighter and last longer.
3.2
CIRCUIT DIAGRAM AND CIRCUIT OPERATION
CHAPTER FOUR
4.0
System construction and system packaging
The design construction of the self-programmable
electronics advertisement board is more or less a very complex design. It
involves the inter connection of some integrated circuits both digital analogue
series of LEDs. Connection in a unique pattern. This inter connection is done
stage by stage owing to the fact that information from the ROM if the processor
which is the drain store house of the program or software is successively
transferred to demultiplexer (74LS154) through port 1 and port 2 of the
processor which relays the information now to the dot matrix light emitting
diodes (LEDs) screen. While port 0 is connection goes to the dot matrix made of
(LEDs).
4.1
COMPONENT SOURCING
Sourcing of component is one the things that can back
when embarked on a project because source of the component that may be easy to
get, it may lead to consulting of data sheet may be in order to get the
equivalent component again it may lead to ordering for the component either
from lagos, Onitsha or even out side the country. Some of the component we used in this project we got from
main market at fine brothers shop ogbete Enugu. While some of the components we
ordered for it from Onitsha some equipment like LM35, LEDs Demultiplexers
(74LS154) etc. some of this component that we ordered is not just because they
are not there in the near by market but because since we needed it in big
quantity in order to reduce the cost we decided to order for it from Onitsha.
So this is how source our components etc.
4.2.1
COST OF COMPONENT LIST
|
S/N
|
COMPONENT
|
DESCRIPTION
|
QUANTITY
|
UNIT PRICE(
|
AMOUNT
|
|
1
|
Micro controller
|
8952
|
1
|
1,400
|
1,400
|
|
2
|
Crystal oscilator
|
12mhz
|
1
|
50
|
50
|
|
3
|
Demultiplexer.
|
74LS154
|
7
|
150
|
1050
|
|
4
|
transistor
|
A1015
|
7
|
20
|
140
|
|
5
|
resistor
|
IK?, 82 ?
|
14
|
10
|
20
|
|
6
|
Capacitor
|
30pf
|
2
|
30
|
30
|
|
7
|
capacitor
|
100mf/16v
|
1
|
5
|
30
|
|
8
|
Rectifier diode
|
IN4007
|
2
|
5
|
10
|
|
9
|
Regulator
|
7805
|
1
|
50
|
50
|
|
10
|
Diode
|
LED
|
1540
|
5
|
7700
|
|
11
|
connecting wire
|
strand
|
10yrds
|
250
|
2500
|
|
12
|
Casing
|
Alumaco
|
-
|
-
|
3500
|
|
13
|
Verod-board
|
strip
|
1
|
150
|
150
|
|
14
|
Soldering lead
|
Aloy lead
|
One role
|
650
|
650
|
|
15
|
Ics sucket
|
Plastic
|
8
|
70
|
|
|
16
|
Transformer
|
12v 500MA
|
1
|
400
|
400
|
|
17
|
Mains lead
|
Two pin
|
1
|
180
|
180
|
Total
N18,460
4.2 CIRCUIT LAYOUT/PROTYPING
4.3
ARRANGMENT
In
this project, interfacing arranged the various section carefully with jumper
connecting wire) to make up the complete section. The following tools helped in
the arrangement of the components. They include soldering iron, soldering,
sucker, brush and pliers, screw driver, saw etc. the soldering iron was used
for precision measurement. Saw was used for cutting while logical probe was
used for logic level. All ICs have their suckets. The sockets as well as the
descrete components were soldered to the vero board. The LEDs on the display
unit were also properly soldered. The transformer was package different for
portability. Hence there is provision for interconnection of the transformer to
the other section of the power supply that was soldered to the vero board.
4.4
PACKAGING
In
the packaging of the project, after the completion of the work, it was then
enclosed in a case to avoid damage. The casing used in packaging the was
composed of different Parts of materials like metal for the flame plastic for
the back and glass for the front some other materials like screw.
CHAPTER FIVE
5.0
SYSTEM TESTING AND RESULT
In
this project various test were carried out on the device to confirm the level
of its performance and efficiency. The test that was carried out was voltage
testing and continuity testing.
5.1
CONTINUITY TESTING
The
10 x 14 dot matrix screen module’s rows and columns were tested with
multiplexer to check for continuity. Also the connection from 8952 to the
demultiplexer and connection from 8952 to transistor and from transistor to the
dot matrix were also tested to check for the continuity.
5.2
VOLTAGE TESTING
The power unit was tested with digital
multiplexer to determine its output voltage. The unit gave a 5 volts output D.C
that the project needed for its function.
5.3
RESULT
After testing for the system
continuity we found out that the whole connection was through and also after
testing for their required D.C voltage for normal operation of the system.
We found out that it was
accurate.
CHAPTER SIX
6.0
CONCLUSION AND RECOMMENDATION
6.1
CONCLUSION
The
construction of an electric advertisement board for organizations and
individuals has been completed and tested okay. This system has made it easier
for more complex and complicated duties to be achieved within some seconds or
there about. Therefore more research work should be done in this type of
display devices, as it would enhance a rapid development in nations industries
to convey the information about their products to the information about their
products to the public. It is very wonderful putting all these electronics
components together to achieve a project like this (self programmable
electronics advertisement board). You can comfortably type in whatever
information you want to display through the computer which over writes the
existing information (previous message).
6.2
RECOMMENDATION
Our recommendation are as
follows:
1.
Everybody should
embark on using self programmable electronics advertisement board than the
conventional way of advertisement because it does not need much space for its
installation.
2.
The department
should get the lecturer that will taking students on micro-processor and
computer electronics related courses, should also make it to be compulsory and
more practical because almost all design now are made mini digitalized and mind
blowing as the software takes care of so many things that would have led to
bulky system.
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