DESIGN AND CONSTRUCTION OF MICRO PROCESSOR BASED DOT MATRIX DIGITAL DISPLAY



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(N)
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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