Design and Implementation of Electronic Billboard

Design and Implementation of Electronic Billboard

Chapter One

OBJECTIVE OF THE STUDY.

The primary objective of this project is to design and implement an electronic billboard that will ensure:

Edit of information that has been designed and displayed.
Elimination or reprinting of work to effect correction on errors found.
Giving of room for update if any new information is needed.
Elimination of cost as a result of reprinting document for update or correction of error.
Visibility of information displayed on the billboard in the day and night.

CHAPTER TWO

LITERATURE REVIEW

Introduction

During the Stone Age, the early man had developed means of communicating with his fellow man by talking, but to reach a wider audience, he uses smoke, gongs, gunshots etc, but later used writing through drawings to make his thoughts conveyed to the recipient.

This was later replaced by the use of words and symbols, alphabetically in writing which is handed from person to person or by mounting such writings on sign posts.

Previously, it was written with pen on a pieces of paper and pasted or with chalk on a board especially in cafes, supermarkets etc.

In some establishments like the fast food joints they use a big rectangular board which is designed by an artist to display the prices of commodities. All these methods have been used in displaying even till today. Hence, the sign as a means of advertising has metamorphosed into the modern Electronic Billboard(EBB).

Light Emitting Diode (LED)

Light Emitting Diode is a two-lead semiconductor light source. It is a p–n junction diode that emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the colour of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor. LEDs are typically small (less than 1 mm²) and integrated optical components may be used to shape the radiation pattern.

Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light. Infrared LEDs are still frequently used as transmitting elements in remote-control circuits, such as those in remote controls for a wide variety of consumer electronics. The first visible-light LEDs were also of low intensity and limited to red. Modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.

Early LEDs were often used as indicator lamps for electronic devices, replacing small incandescent bulbs. They were soon packaged into numeric readouts in the form of seven-segment displays and were commonly seen in digital clocks. Recent developments have produced LEDs suitable for environmental and task lighting. LEDs have led to new displays and sensors, while their high switching rates are useful in advanced communications technology.

LEDs have many advantages over incandescent light sources, including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. Light-emitting diodes are used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, camera flashes, and lighted wallpaper. As of 2017^[update], LED lights used for homes, rooms lighting are as cheap or cheaper than compact fluorescent lamp sources of comparable output. They are also significantly more energy efficient and, arguably, have fewer environmental concerns linked to their disposal.

PRINCIPLE OF OPERATION.

J.B Gupta (2010) states A P-N junction can convert absorbed light energy into a proportional electric current. The same process is reversed here (i.e. the P-N junction emits light when electrical energy is applied to it). This phenomenon is generally called electroluminescence, which can be defined as the emission of light from a semiconductor under the influence of an electric field. The charge carriers recombine in a forward-biased P-N junction as the electrons cross from the N-region and recombine with the holes existing in the P-region. Free electrons are in the conduction band of energy levels, while holes are in the valence energy band. Thus the energy level of the holes is less than the energy levels of the electrons. Some portion of the energy must be dissipated to recombine the electrons and the holes. This energy is emitted in the form of heat and light.

The electrons dissipate energy in the form of heat for silicon and germanium diodes but in gallium arsenide phosphide (GaAsP) and gallium phosphide (GaP) semiconductors, the electrons dissipate energy by emitting photons. If the semiconductor is translucent, the junction becomes the source of light as it is emitted, thus becoming a light-emitting diode. However, when the junction is reverse biased, the LED produces no light and, the device is damaged if the potential is great enough.

Fig.1 Diagram of Light Emitting Diode

Advantages of LED

Efficiency:LEDs emit more lumens per watt than incandescent light bulbs. The efficiency of LED lighting fixtures is not affected by shape and size, unlike fluorescent light bulbs or tubes.
Colour:LEDs can emit light of an intended colour without using any colour filters as traditional lighting methods need. This is more efficient and can lower initial costs.
Size:LEDs can be very small (smaller than 2 mm²) and are easily attached to printed circuit boards.
Warmup time:LEDs light up very quickly. A typical red indicator LED achieves full brightness in under a microsecond. LEDs used in communications devices can have even faster response times.
Cycling:LEDs are ideal for uses subject to frequent on-off cycling, unlike incandescent and fluorescent lamps that fail faster when cycled often, or high-intensity discharge lamps (HID lamps) that require a long time before restarting.
Dimming:LEDs can very easily be dimmed either by pulse-width modulation or lowering the forward current. This pulse-width modulation is why LED lights, particularly headlights on cars, when viewed on camera or by some people, appear to be flashing or flickering. This is a type of stroboscopic effect.
Cool light:In contrast to most light sources, LEDs radiate very little heat in the form of IR that can cause damage to sensitive objects or fabrics. Wasted energy is dispersed as heat through the base of the LED.
Slow failure:LEDs mostly fail by dimming over time, rather than the abrupt failure of incandescent bulbs.
Lifetime:LEDs can have a relatively long useful life. One report estimates 35,000 to 50,000 hours of useful life, though time to complete failure may be longer. Fluorescent tubes typically are rated at about 10,000 to 15,000 hours, depending partly on the conditions of use, and incandescent light bulbs at 1,000 to 2,000 hours.
Shock resistance:LEDs, being solid-state components, are difficult to damage with external shock, unlike fluorescent and incandescent bulbs, which are fragile.
Focus:The solid package of the LED can be designed to focus its light. Incandescent and fluorescent sources often require an external reflector to collect light and direct it in a usable manner. For larger LED packages total internal reflection (TIR) lenses are often used to the same effect. However, when large quantities of light are needed many light sources are usually deployed, which are difficult to focus or collimate towards the same target.

Disadvantages of LED

Initial price:LEDs are currently slightly more expensive (price per lumen) on an initial capital cost basis, than other lighting technologies. As of March 2014^[update], at least one manufacturer claims to have reached $1 per kilolumen. The additional expense partially stems from the relatively low lumen output and the drive circuitry and power supplies needed.
Temperature dependence:LED performance largely depends on the ambient temperature of the operating environment – or thermal management properties. Overdriving an LED in high ambient temperatures may result in overheating the LED package, eventually leading to device failure. An adequate heat sink is needed to maintain long life. This is especially important in automotive, medical, and military uses where devices must operate over a wide range of temperatures, which require low failure rates. Toshiba has produced LEDs with an operating temperature range of −40 to 100 °C, which suits the LEDs for both indoor and outdoor use in applications such as lamps, ceiling lighting, street lights, and floodlights.
Voltage sensitivity:LEDs must be supplied with a voltage above their threshold voltage and a current below their rating. Current and lifetime change greatly with a small change in applied voltage. They thus require a current-regulated supply (usually just a series resistor for indicator LEDs).
Colour rendition:Most cool-white LEDs have spectra that differ significantly from a black body radiator like the sun or an incandescent light. The spike at 460 nm and dip at 500 nm can cause the colour of objects to be perceived differently under cool-white LED illumination than sunlight or incandescent sources, due to metamerism, red surfaces being rendered particularly poorly by typical phosphor-based cool-white LEDs.
Area light source:Single LEDs do not approximate a point source of light giving a spherical light distribution, but rather a lambertian So LEDs are difficult to apply to uses needing a spherical light field; however, different fields of light can be manipulated by the application of different optics or “lenses”. LEDs cannot provide divergence below a few degrees. In contrast, lasers can emit beams with divergences of 0.2 degrees or less.
Electrical polarity: Unlike incandescent light bulbs, which illuminate regardless of the electrical polarity, LEDs only light with correct electrical polarity. To automatically match source polarity to LED devices, rectifiers can be used.
Light pollution: Because white LEDs, especially those with high colour temperature, emit much more short wavelength light than conventional outdoor light sources such as high-pressure sodium vapour lamps, the increased blue and green sensitivity of scotopic vision means that white LEDs used in outdoor lighting cause substantially more sky glow. The American Medical Association warned on the use of high blue content white LEDs in street lighting, due to their higher impact on human health and environment, compared to low blue content light sources (e.g. High-Pressure Sodium, PC amber LEDs, and low CCT LEDs).
Efficiency drop:The efficiency of LEDs decreases as the electric current Heating also increases with higher currents, which compromises LED lifetime. These effects put practical limits on the current through an LED in high power applications.
Impact on insects:LEDs are much more attractive to insects than sodium-vapour lights, so much so that there has been speculative concern about the possibility of disruption to food webs.
Use in winter conditions:Since they do not give off much heat in comparison to incandescent lights, LED lights used for traffic control can have snow obscuring them, leading to accidents.

Applications of LED

LED uses fall into four major categories:

Visual signals where light goes more or less directly from the source to the human eye, to convey a message or meaning
Illumination where light is reflected from objects to give visual response of these objects
Measuring and interacting with processes involving no human vision.
Narrow band light sensors where LEDs operate in a reverse-bias mode and respond to incident light, instead of emitting light.

CHAPTER THREE

SYSTEM ANALYSIS AND METHODOLOGY

Introduction

This chapter will discuss the driving principle behind the led display board and basic principle of signal multiplexing. Before this design was achieved, a lot of time was devoted to research on the possible ways of making led display. We shall also discuss these methods, basic principle of operation and their loop holes. We shall also discuss the software and programming language to be used as well as the microcontroller features.

Direct Dot matrix led method

Basically, An LED dot matrix display consists of a matrix of LED’s arranged in a rectangular configuration. The desired character or graphics can be displayed by switching ON /OFF a desired configuration of LED’s. Common display configurations available are 7×5, 8×8, 7×15, etc. LED dot matrix can be used in simple display applications where the resolution is not a big concern. The figure below shows the arrangement of LEDs in a typical 7×5 dot matrix display.

CHAPTER FOUR

Design and Implementation

This chapter presents the schematic diagram and construction procedures applied in order to achieve the complete working project. This will be divided into two major parts, software and hardware. Hardware basically describes how the circuit was connected from the power supply circuit down to each component included in the project while the software entails the embedded commands and protocol involved in making all the hardware operate optimally.

Hardware Design

From the block diagram below, each component of the entire project will be explained in terms of circuit design with tangible reason for each component.

CHAPTER FIVE

TESTING, RECOMMENDATION AND CONCLUSION

TESTING

Testing involves the use of Multimeter to measure DC current, voltage and resistance in the circuit. Multimeter can be used as an ammeter, a voltmeter, an ohmmeter; by operating a multi-position knob on the meter. They can measure DC as well as AC. There are also special functions in a multimeter like ‘Detecting a Short Circuit’, testing transistors and some have additional features for measuring capacitance & frequency.

Measuring resistance with a DIGITAL Multimeter

Set the meter to a resistance range greater than you expect the resistance to be. Notice that the meter display shows “off the scale”
Touch the meter probes together and check that the meter reads zero. If it doesn’t read zero, turn the switch to ‘Set Zero’ if your meter has this and try again.
Put the probes across the component. Avoid touching more than one contact at a time or your resistance will upset the reading.

If the meter reads 1, this means that the resistance is more than the maximum, which can be measured on this range and you may need to switch to a new position, 2000 k or so, to take the reading.

Measuring Voltage using a voltmeter

Voltmeters are always connected in parallel with the component or components under test, any current through the voltmeter will contribute to the overall current in the tested circuit, potentially affecting the voltage being measured. Voltmeter has infinite resistance, so that it draws no current from the circuit under test.

The diagram below shows how to measure the voltage applied across the circuit. The input voltage is AC signal 220v – 240v which was converted to a dc voltage of 19v by an adapter. The output (dc voltage) is read from the display of the voltmeter.

CONCLUSION

The researcher has tried as much as possible to design and analyze the features involved in designing an electronic billboard (EBB) in full operations and comparing its performance with the design objectives, it may be concluded broadly that the system conformed to, and worked in accordance with the design requirement.

Electronic billboard is broadly used in bank to display exchange rate, it has also found its use in stadium, supermarket, bar and for weather forecast.

Getting a system to satisfy there objectives as afore stated in the chapter one was quite a tedious task but the end results justify the effort into ensuring its proper operations.

We therefore conclude that the design was really successful.

RECOMMENDATION

For further improvement in the design and construction of the electronic bill board (EBB) system or any other kind of display system, the following recommendations are useful;

In order to get a full multi-coloured electronic bill board or display capability, electrochemical displays (ECDs) should be incorporated in the design.
Always incorporate a diode and transistor to ensure that the LED (light emitting diodes) stays on after each play.
The design of the base could be changed so that the whole bill board is mounted on a swiveling base to allow view from different angles.
Multi-colour displaying should be considered more than one colour.
Further research should be carried out on this project to find out the possibility of making the work visible in ambient light.
Finally, the application of the EBB is recommended for all supermarkets, fast foods outlets and hotels etc.

REFERENCES

Farago, PS (1961), An Introduction to Linear Network Analysis, The English Universities Press Ltd. pg. 18–21
B Gupta (2010), Basic Electrical and Electronics Engineering.S.K. Kataria andsons publishers. Pg 545 – 547.
K. Mehta, Rohit Mehta (2005), Principles of Electronics. S. Chand & Company Ltd. pg.203
Wu, Fa Yueh; Yang, Chen Ning (2009). Exactly Solved Models: A Journey in Statistical Mechanics : Selected Papers with Commentaries (1963–2008). World Scientific. pp. 489
“Wi-Fi Alliance: White Papers”. www.wi-fi.org. Retrieved 2009-10-22.
“Wi-Fi Alliance: Programs”. www.wi-fi.org. Retrieved 2009-10-22.
“Wi-Fi Alliance”. TechTarget. Retrieved 8 April2016.
“Wi-Fi Alliance® statement regarding “Super Wi-Fi””. Wi-Fi Alliance. Retrieved April2016.
“London-wide wi-fi by 2012 pledge”. BBC News. 2010-05-19. Retrieved 2010-05-19.

Related Topics:

Other Topics