CHAPTER ONE
1.0 INTRODUCTION
Current trends in electric energy generation are moving towards the utilization of the environment friendly sources of energy, represented by the wind and solar energy ones as a supplementary energy resource.
The solar based one is the more attractive because it is characterized by being free, incur no fuel cost, abundant, limits less, distributed all over the world, pollution free, and require little maintenance. Maximizing power output from a solar system is desirable to increase efficiency and in order to maximize power output from the solar panels, one need to keep the panels aligned with the sun. As such, a means of tracking the sun is required. Efficient collection of maximum solar irradiance (MSI) on a flat plate type photovoltaic solar panels or a cylindrical parabolic solar reflector requires adjustments of two parameters of the energy collecting surface namely the angle of Azimuth, and the angle of tilt, of the surface to be illuminated.
As the elevation angle of the sun remains almost invariant in a month and varies little (latitude + 100) in a year, there is no need for automatic adjustment of the tilt angle. Everyday, the sun rises in the east, moves across the sky and sets in the west. If one could get a solar panel to turn and look at the sun all day hours, then it could receive the maximum amount of sunlight possible and convert it into the more useful energy (electricity).
The current of the solar module is very sensitive to the Isolation of the sun. Small tilt in the solar module makes the current drop rapidly. It has been estimated that the yield from solar panels can be increases by 30 to 60 percent by utilizing a single axes tracking system instead of a stationary array. This is a far more cost effective solution than purchasing additional solar panels. This project develops an automatic system which will keep the solar panels aligned with the sun in order to maximize efficiency.
1.1 BACKGROUND INFORMATION OF THE PROJECT
This section presents the background information on the main subsystems of the project. Specifically, this section discusses on Light sensor, micro-controller and stepper motor theory in order to provide a better understanding as to how they relate to the solar tracker.
Hence, the discussion of the light sensor will include the following;
(i) Illumination
(ii) How to measure illumination
(iii) The instrument used in measuring illumination
(iv) How the instrument works
(v) How a light sensitive element works
Also the discussion of the micro-controller will include the following;
(i) Basic principles and knowledge on how to program a micro-processor.
(ii) How to program a micro processor in order to give an output.
(iii) How to use the output of the micro-processor to control the behaviour of motor driven circuits.
1.1.1 LIGHT SENSOR
Light sensor’s are among the common sensor’s type. The simplest optical sensor is the photo resistor which may be a cadmium sulphide (Cds) type or a Gallium Arsenide (GaAs) type. The next step in complexity is the photodiode followed by the phototransistor. The sun tracker uses cadmium sulphide (Cds) photocell for sensing the illumination intensity of the sun. This is the least complex type of light sensor. Below are basic explanation about SUN ILLUMINATION and How it is measured, before the sensing of it with a light sensitive element.
1.1.2 SUN ILLUMINATION AND ITS MEASUREMENT
Illumination is the act of production of radiant energy. It is the deliberate application of light to achieve some practical effect. Lighting includes the use of both artificial light sources such as lamps and light fixtures as well as natural illumination by capturing daylight (sun).
Sunlight in the broad sense is the total frequency spectrum of electromagnetic radiation given off by the sun, particularly infrared, visible, ultra violet light. A PYRANOMETER is a type of actinometer used to measure a broadband solar irradiance on a planer surface and is a sensor that is designed to measure the solar flux density (in watts per meter square) from a yield of 180 degrees.
1.1.3 HOW A PYRANOMETER WORK When sunlight falls on a pyranometer, the thermopile sensor produces a proportional response typically in 30 seconds or less. The more sunlight, the hotter the sensor gets and the greater the electric current it generates. The thermopile is designed to be precisely linear (so a doubling of solar radiation produces twice as much current) and also has a directional response. It produces maximum output when the sun is directly overhead (at midday) and zero output when the sun is on the horizon (at dawn or dusk). This is called cosine response (or cosine correction), because the electrical signal from the pyranometer varies with the cosine of the angle between the sun rays and the vertical.
1.1.4 HOW A LIGHT SENSITIVE ELEMENT WORKS The light sensitive element that is used in this work is called LIGHT DEPENDENT RESISTOR (LDR). The LDR is a resistor whose resistance decreases with increasing light intensity. It can also be referenced to as a photo conductor. A photo resistor is made of high resistance of semi conductor. If light falling on the device is of high enough frequency, photons absorbed by the semi conductor give bound electrons enough energy to jump to the conduction band. The resulting free electrons and its holes partner conduct electricity, thereby lowering resistance. The reverse is the case when darkness falls on the LDR for this will increase its resistance. This characteristic of the LDR is used to vary the input voltage into the comparator as the sun moves over it.
1.1.5 MICROCONTROLLER A microcontroller (sometimes abbreviated MCU) is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications. Microcontrollers are used in automatically controlled products and devices, such as automobile engine control system, implementable medical devices, remote controls, office machines, appliances, power tools, toys and other embedded systems. By reducing the size and cost compared to a design that uses a separate microprocessor, memory, and input/output devices, microcontrollers make it economical to digitally control even more devices and processes. To program a microcontroller, first one need an assembler, compiler and a device programmer, then you have to learn about ASM, Pic Basic or Pic C. finally one need to know the device itself, like all the registers and the pins functions.
1.1.6 SUPER JACK DC MOTORIZED ATUATOR THEORY
A super jack is a low noise, high performance actuator used in control applications and it has a different stroke length of 6,8,10 and 12 inch. A super jack can otherwise be called a dc motorized actuator which it workability primarily depends on the dc motor component in it.
A dc motor component converts electrical energy (voltage or power source) to mechanical energy (produce a rotational motion) and it run on direct current. The dc motor works on the principle of Lorenz force which states that when a wire carrying current is placed in a region having magnetic field, then the wire experience a force. This Lorenz force provides a torque to the coil to rotate.
1.2 OBJECTIVE OF THE STUDY
The aims and objective of this study is to design and construct a microcontroller based SUN automatic tracking system with a working software which will always keep the sun panel align with the sun in order to receive maximum sunlight energy radiated and also maximize efficiency.

1.3 SIGNIFICANCE OF THE STUDY
Although, other process of generating electrics power exist such as DIESEL Power PLANT, NUCLEAR POWER PLANT, HYDRO ELECTRICITY and GAS TURBINE PLANTS, They create or produce DANGEROUS POLLUTANTS such as GREEN HOUSE GASSES which causes lots of harm to human life and the Ecosystem (MAN’S HABITAT). The maximum ENERGY FROM the SUN (SOLAR IRRADIANCE) can be track and harnessed efficiently in order to generate electricity for human use. The sun tracking system is more attractive because it is characterized by being free, incur no fuel cost, it is abundant, limited less, distributed all over the world, pollution free and require little maintenance.

1.4 SCOPE OF THE STUDY The method of tracking the sun energy in order to obtain the maximum intensity which is capable of converting the SUN ENERGY to electric power. This type of ENERGY can be applied in several ways. Solar power produces massive amount of electricity for domestic and commercial area. Solar energy application are available in sectors like residential, commercial, industrial and agriculture. The solar system do comes with battery which stores the excess amount of energy. This energy can be used when the solar is no more producing electricity like in the night, during rain or when the cloud covers the Sun.

1.5 LIMITATION OF THE DESIGN
Though the main aim of the sun tracker is to track the sun energy radiated at an appropriate angle and convert the maximum intensity of the energy track to electricity. But instead of using a photo voltaic panel which convert the sun energy to electrical energy, a pyranometer is used which is placed at the centre of the rectangular panel to measure the intensity of the sun. This proves that the angle in which the sun panel is situated is directed to where the sun intensity is high, in which if a photovoltaic panel is used it will receive maximum intensity at that position, to convert the power to electrical energy.

1.6 THESIS LAYOUT CHAPTER ONE begins with the introduction of the study, it follows by presenting a background information on the main subsystem which are the light sensors, microcontroller and the super jack dc motorized actuator as they are applied to the study. It further discussed on the objective of the study, significance of the study, scope of the design and limitation of the design.
CHAPTER TWO deals with the literature review which gives a full detail of the past design of the sun tracker and also, it explains the inventors and the different design devices of sun tracker till date.
CHAPTER THREE emphasizes on materials and methods adopted based on the historical background of the sun tracker.
CHAPTER FOUR brings to the light the design, physical construction analysis and a software system operation explanation, also with the need for the efficiency of the study.
CHAPTER FIVE give a detail explanation of statistical data showing the world power demand and efficiency of power generation. It also give a discussion of design result and future work.
FINALY, CHAPTER SIX discuss on the conclusion, recommendation and reference.

CHAPTER TWO
2.0 LITERATURE REVIEW There are a number of works proposed by many researchers to track the sun. kalogiron and Alata etal suggested a tracking system which can be used with single axis solar concentrating systems, Roth etal and Bakos constructed and tested two axis tracking system. Different types of one axis tracking systems have been applied in the literature. Tomson described mainly the performance of photovoltaic voltage (PV) modules with daily two position in the morning and the afternoon. Results indicated that the seasonal energy yield was increased by 10 -20 percent over the yield from a fixed south facing collector tilted at an optimal angle. Huang and sun has designed the solar tracking system called “one axis three position sun tracking pv module” with low concentration ratio reflector. The one-axis tracking mechanism adjusted the pv position only at three fixed angles. These are the morning, the noon and the afternoon. An experiment performed in the present study indicated that economic analysis showed that the price reduction was between 20% and 30% for the various market prices of flat pv modules.
Abu-Khadera etal investigated the effects of multi axes sun tracking systems on the electrical generation of a flat photo-voltaic system (FPVS) which was carried out to evaluate its performance under jordarian climate. Multi axes (N-S, E-W, vertical) electromechanical sun-tracking system was designed and constructed. The measured variables were compared with that at fixed axis. It was found that there was an overall increase of about 30-45% in the output power for the North-South axes (N-S) tracking system compared to the fixed PV system.
Also, it was found that the North-South axes sun tracking was the optimum.
Bakos (S) performed to investigate the effect of using a continous operation two-axes tracking on the solar energy collected. The collected energy was measured and compared with that on a fixed surface tilted at 41 toward the south. The result showed that the measured collected energy on the moving surface was considerably larger (up to 46.46%) compared with the fixed surface. Abdallah implemented four electromechanical sun tracking systems, two axes, one axis vertical, one axis east-west and one axis north-south, were designed and constructed for the purpose of investigating the effect of tracking on the current, the voltage and the power, according to the different loads. The results indicated the increase of electrical power gain up to 43.87% for the two axes. 37.53% for the east west, 34.43% for the vertical and 15.69% for the north-south tracking, as compared with the fixed surface inclined 32 to the south in Amman. There are also many different controllers such as Pc, PLC, PLA controller and electro-optically to implement the control techniques . In addition to this Georgiev et al expressed that modern measuring and registering system for actual data more easily than conventional system. When the literatures are analyzed, the parameters such as the installation, the mechanism, the cost, the efficiency, the design and the maintenance have been given as important features depend on tracking methods as given in table 1 below.
Table 1; COMPARISON OF SOLAR SYSTEMS
PARAMETERS FIXED ONE-AXIS TWO AXES DEVELOPMENT
Installation
Mechanism
Cost
Efficiency
Design
Maintenance Easy
No mechanism
Cheap

Reference Efficiency
Simple
Less Easy simple moderate
10-35% fixed system moderate moderate Difficult
Complicated
Expensive
25-45% fixed system complicated more Easy
Simple
Moderate
10-45% fixed system simple less The design presented is splendid for outpost systems that hardly require any monitoring and needs moderate maintenance to improve their efficiency.

CHAPTER THREE
3.0 MATERIALS AND METHODS
3.1 INTRODUCTION In the actualization of this project, some certain electronic components, device and method were employed, these include the followings
1. Relay (Polarize relay)
2. Decoder (7447)
3. Light Dependent resistor,
4. Crystal Oscillator
5. A stripe Vero-board
6. A super jack (Dc motorized Actuator)
7. An AT89C51RD2 microcontroller
8. An AT89C2051 microcontroller
9. Switches
10. Seven segment display (Countdown timer)
11. Diodes
12. Transistors
13. Resistors
14. Connectors
15. A regulator (7805)

EXPLANATIONS;
1. RELAY: A relay is an electrically operated switch. Many relays use an electromagnetic to operate a switching mechanism mechanically, but other operating principles are also used.
Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several circuits must be controlled by one signal. A type of relay that can handle the high power required to directly control an electric motor or other loads is called a contactor. Solid state relays control power circuits with no moving parts instead using a semiconductor device to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuit from overload or faults. A simple electromagnetic relay consists of a coil of wire wrapped around a soft iron core, an iron yoke which provides a low reluctance path for magnetic flux, a movable iron armature, and one or more sets of contacts. The armature is linked to the yoke and mechanically linked to one or more set of moving contacts. It is held in place by a spring so that when the relay is de-energized there is an air gap in the magnetic circuit. Some relays types have fewer sets of contacts depending on their function. When an electric current is passed through the coils, it generates a magnetic field that activates the armature and the consequent movement of the movable contacts either makes or breaks (depending upon construction) a connection with a fixed contact. They are so many types of relays, but in this project work, the following two types were used.
1) Polarized relay
2) Contactor (used for switching electric motor)/
In this project work, the above two types of relay were used to change the polarity of the electric motor in order to initiate the Bi-directional movement of the motor and as well as a switch (contactor).
Fig 3.00 circuit symbol of a relay

NB: SPDT - Single pole double Terminal DPDT- Double pole double terminal

2. DECODER: A decoder is a device which does the reverse operation of an encoder, undoing the encoding so that the original information can be retrieved. The same method used to encode is usually just reversed in order to decode. It is a combinational circuit that converts binary information from n input lines to a maximum of 2n unique output lines. In digital electronics, a decoder can take the form of multiple-input logic circuits that converts coded input into coded outputs, where the input and output codes are different. In this project work, a decoder was used to convert a Binary coded decimal (BCD) of the AT89C51RD2 microcontroller to a seven segment display form which can be visualized and as well readable. These decoders were three in number and of the same values (7447 Decoder). A diagram of a 2-to-4 line single bit decoder can be shown as below

Fig 3.10 Example of 2-to-4 line single bit decoder
3. LIGHT DEPENDENT RESISTOR (LDR) An LDR is an Acronym for light dependent resistors, it is a device whose resistance false (decreases) with an increase in the intensity of light that falls on it, and in the other hand increase with a decrease of the light intensity.
LDRs are very useful especially in light/dark sensor circuits. Normally, the resistance of an LDR is very high, sometimes as high as 1000,000 ohms, but when they are illuminated with light, resistance drops drastically. The symbol of an LDR as well as its circuit diagram can be shown in the figure below.

Fig 3.12 Light sensor circuit The above circuit of fig 3.14 is an example of light sensor circuit. When the light intensity is low, the resistance of the LDR is high. This prevents current from flowing to the base of the transistors. Consequently the LED does not light. However, when light shines onto the LDR, its resistance falls and current flows into the base of the first transistor and then the second transistor which will cause the LED to light. The preset resistance can be turned up or down to increase or decrease resistance, in this way it can make the circuit more or less sensitive. In this project, “Micro controller based sun tracker” the LDR is used as a sensor circuit which senses the direction where the suns illumination (intensity) is high in order to send signal through necessary components of the circuit and as a result move the plate towards that direction with the help of the D.C motor (i.e. motorized actuator) in order to trap the available suns illumination.
4. CRYSTAL OSCILLATOR Crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric materials to create an electrical signal with a very precise frequency. This frequency is commonly used to keep track of time (as in quartz wristwatches) to provide a stable clock signal for digital integrated circuits, and a stabilize frequencies for radio transmitters and receivers. The most common type of piezoelectric resonator used is the quartz crystal, so oscillator circuits designed around then became known as crystal oscillator. In this project work, crystal oscillator is used to match the fast moving frequency of the microcontrollers (i.e. AT89C51RD2) and (AT89C2051) which is in so many mega Hertz, i.e. at about 12MHz. this means that the crystal oscillator is used to generate a clock pulse at which the micro controller operate upon (i.e. 12 MHz). Fig. 3.13 The circuit diagram of a crystal oscillator can be shown in the figure below.

Electronic symbol for piezoelectric crystal resonator(Crystal oscillator).

Fig 3.14 an equivalent circuit of a crystal Oscillator.
Crystal freq. = 12MHz
C1 = C2 = 33PF From the equivalent circuit of a crystal oscillator in fig 3.14, the two capacitors, C1 and C2 connected across the oscillator cause the parallel resonance to shift downwards. This can be used to adjust the frequency at which the crystal oscillates. With regards to this project work, the two capacitors C1 and C2 which are 33 Pf each function as to filter out the sine-wave component of the signal that enters the microcontroller.
5. VERO-BOARD: Vero-board is a circuit prototype board somewhere between solder less breadboards and the printed circuit boards, PCBs. It allows for making of a more permanent circuit, which has more reliable connections than with bread board but without the expense of etching or ordering PCBs.
It consists of trips of metals on a side of a board and grid of holes spaces of about 0.1 (i.e. 2.54mm) apart. This board was used in this project to connect the components with the directives of the circuit diagram in order to confirm the workability of the circuit, or else the circuit will be rearranged by redrawing it or adding more needful components.

Fig 3.15 A diagram of Vero board
6. Super jack (dc motorized actuator).
A super jack or D.C motorized actuate is a linear actuator which creates motion in a straight line, as contrasted with circuit motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machineries. The diagram of super jack can be shown as below;

Fig 3.17 Bottom view (DC motor not included)
The shaded nut interlocks with the outer sliding cylinder to prevent the nut/un shaded cycle assembly from rotating with respect to the sliding outer cycle. From the diagram of fig. 3.16, the DC motor is a rotary electric motor with a rotor and stator circular magnetic field components peeled off and lay in a straight line. The rotary motor would spin around and re-use the same magnetic pole faces again. When the rotary motor rotates in a clockwise direction, it makes the lead screw to rotate also in a clockwise direction causing the inner cylinder to move inward. On the other hand, when the rotary motor rotate in an anticlockwise direction, it also make the lead screw to rotate in an anticlockwise direction, thereby causing the inner cylinder to move outward. The clockwise and anti-clockwise movement of the rotary motor depends on the relay and polarity connection to the motor. In this project, the super jack (motorize actuator is used to control the movement of the solar plate (Panel) in both eastward and westward direction.

Fig. 3.18 Front view of super jack for the control of the solar tracker MICRO-CONTROLLER (AT89C51RD2): An AT89C51RD2 micro controller is a high performance CMOS flash version of the 80C51 CMOS single chip 8-bit micro controller. It contains a 64-kbyte flash memory block for code and for data. The 64-kbytes flash memory can be programmed either in parallel mode or in serial mode with the ISP capability or with software. The programming voltage is internally generated from the standard Vcc pin. The AT89C51RD2 provides 2048bytes of EEPROM for nonvolatile data storage. In addition the AT89C51RD2 has a programmable counter array, an XRAM of 1792 bytes, a hardware watchdog timer, SP1 interface, keyboard, a more versatile serial channel that facilitates multi-processor communication (EUART) and a speed improvement mechanism (X2 mode). In this project, the AT89C51RD2 was used to receive signal from the sensor circuit in order to send signal or directives to the other microcontroller (AT89C2051) with the help of delay program that is being written into it, which will result to the turning of the solar plate to either direction when the need arrives.

Fig 3.19. The diagram of AT89C51RD2 can be shown below
7. AT89C2051 MICROCONTROLLER:
An AT89C2051 is a low-voltage; high performance CMOS 8-bit microcomputer with 2kbytes of flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high-density non volatile memory technology and is compatible with the industrial standard of MCS-51 instruction set. By combining a versatile 8-bit CPU with flash on a monolithic chip, the Atmel AT89C2051 is a power-full micro computer which provides a highly flexible and cost effective solution to many embedded control application. In this project work the AT89C2051 chip was used in sending signal to the relay in order to cause the D.C motor (motorized actuator) to pull outward or inward there by rotating the solar plate in either direction (Eastward or Westward). This sending of signal to the relay, can only be done by the AT89C2051 whenever the AT89C51RD2 chip wants it to do so, according to how it was being programmed.
Fig 1.20 The diagram of AT89C2051 chip can be shown below.

8. SWITCH
In electrical engineering, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another. The most familiar form of switch is manually operated electromechanical device with one or more sets of electrical contacts, which are connected to external circuits. A switch may be directly manipulated by a human as a control signal to a system, such as a computer keyboard button or to control power flow in a circuit such as a high switch. Automatically operated switches can be used to control the motions of machine. In this project, the switch used was a one way electromechanical switch, which was used in powering the whole circuit in order for current to flow through the devices.
9. LINEAR REGULATORS
In electronics, a linear regulator is system used to maintain a steady voltage. The resistance of the regulator varies in accordance with the load resulting in a constant output voltage the regulating device is made to act like a variable resistor, continuously adjusting a voltage divider network to maintain a constant output voltage and continually dissipating the differences between the input and regulated voltages as waste heat. By contrast, a switching regulator uses an active device that switches on and off to maintain average value of output. Because the regulated voltage of a linear regulator must always be linear than input voltage, efficiency is limited & the input voltage must be high enough to always allow the active device to drop some voltage. In this project a 7805 regulator was used to regulate the DC voltage to 5v which was used by the AT89C51RD2 microcontroller and other device components.
Fig 3.21 Regulator

Table 2: Pin Description
PIN NO FUNCTION NAME
1. Input voltage (54-18v) Input
2. Ground (10v) Input
3. Regulated input; 5v (4.8v-5.2v) output

10. SEVEN SEGEMENT DISPLAY This is an assembly of light emitting diode – bars (segments) each which can be powered individually. They are arranged and labeled as shown in the diagram below
Fig 3.20 Arrangement of seven segment display

The arrangement of the display is in form of ‘8’ in hexadecimal form. The display depends on the powering of the segment. For example, when all the segments are being powered on, the display will show the number ‘8’. It can display number from zero (0) to Nine (9) depending on how the segments are being powered. In this project work, seven segment displays are used to display the converted Binary Coded Decimal (BCD) signal from the AT89C51RD2 to microcontroller by the decoder (7448 decoder). The display are being arranged in common anode form in which all the anode connections of the LEDs are joined together to logic “1” and the individual segments are illuminated by connecting the individual cathode terminals to a ‘low’ logic “0” signal.
11. DIODE
A diode is a device that allows electric current to pass through it in only one direction (called the diode forward direction), while blocking current flow in the opposite direction (the reverse direction). This unidirectional behavior of a diode is called rectification and it is used to convert alternating current to direct current. In this project, the Diode used is of the value IN4005, which was being used as a rectifier to convert the amplified signal from the transistor to a pure dc signal which enters into the relay that links the AT89C51RD2 Microcontroller with the help of a Regulator (7805 regulator).
Fig 3.22 the diode symbol is as shown below
Anode Cathode
(+) ( –) 1.2 TRANSISTORS A transistor is a semiconductor device used to amplify switching and produce high and low frequency. It switch the electronics and power signal in the circuit. They are two types of transistor vise;
1) Uni-junction transistor and
2) Bi-polar junction transistor In this project work, we used an NPN type of BJT transistor which consists of a layer of P-doped semi conductor between two layers of N-doped materials. A small current entering the base is amplified to produce a large collector and emitter current (i.e when the base is high relative to the emitter). In the ON state, current flows between the collector and emitter of the transistor. In this project work, the two NPN transistors (BC337 each) used were of the same value and are used to amplify the current that is from the sensor which enters the relay.
Fig 3.23 The symbol of an NPN transistor can be shown below. C B E 1.3 RESISTOR It is a circuit element that converts energy to heat energy. Resistor may be connected in series or in parallel depending on what one want to achieve. It is an opposing force to the flow of electricity. When current flows through a resistor, energy is used and it creates heat. The resistance of a resistor is measured in Ohms. In this project a 10k ohms resistor was used to resist and measure the sun signal that is being fed in by an LDR.
Hence, if the sun signal is not up to or above the resistor value, this sun signal will not pass. This is because there are other rays like moon ray which radiate in the night which it energy ray is very low and which is not needed in this project. The resistor is also used in other sub-circuit. The resistor symbol can be shown as below. Fig 3.24 Symbol of a resistor
METHODS
The methods simply means the way these component and other materials were put together to achieve our aim. First of all, the following should come into your mind.
● What will send signal or how sill signal be sent to this circuit.
● How will this circuit receive signal
● How will this circuit put OFF or ON the expected system
Therefore, the answer to these question answers the methodology.
To assemble a microcontroller sun tracker we first placed the active components one after the other using the circuit diagram to make reference. Each one placed was neatly soldered on the board making sure that it did not apply excessive heat after soldering the active components we put the passive components one after the other and soldered them as well.
This was done after positions of the components were carefully marked out on the board. The resistor of which the voltage was impressed through was connected in series to reduce the incoming voltage to the desire of some circuit components.

CHAPTER FOUR
4.0 DESIGN ANALYSIS AND CONSTRUCTION
4.1 DESIGN ANALYSIS The building of the project started by studying the original circuit and its specification. After understanding the principles of operation of the device, we move to modify the circuit
4.2 MODIFIED BLOCK DIAGRAM The block diagrams of the sequence operation of the circuit at different stages are shown in the next page;

Fig 4.00 BLOCKS DIAGRAM OF THE MODIFIED CIRCUIT
4.1 POWER SUPPLY UNIT The Power Supply Unit (PSU) supplies a DC power voltage to the whole circuit. It is a DC power supply in which 24v is being supplied to the relay unit which also powers the motor. Also a 12v is being supplied to the sensor unit to take care of the sensor unit and other unit
4.2 SENSOR UNIT
The sensor unit is made up of light dependence resistor (LDR), NPN transistor, variable resistor and relay. The sensor unit received a sun ray which will signal the AT89C51RD2 microcontroller. It also switch ON and OFF the circuit either when there is sun ray in the day and when there is no sun ray in the nigh
4.3 AT89C51RD2 MICROCONTROLLER UNIT
This particular microcontroller is made up of the regulator and the micro controller itself. The regulator used is a 7805 regulator which regulate the 12DC to 5 volt to be used by the AT89C51RD2 microcontroller and Display unit. The microcontroller is programmed in 6hours time interval in which after 6 hours it will send a pulse signal to the AT89C2051 microcontroller to rotate the motor eastward or westward depending whether it is in the morning or afternoon.
4.4 THE AT89C2051 MICROCONTROLLER
This unit receive pulse signal from the 89C51 microcontroller to control the movement of the motor and panel. It informs the panel to move either in an eastward or westward direction for 58 seconds.
4.5 THE RELAY AND MOTOR UNIT
The relay receive pulse signal from the AT89C2051 microcontroller to turn the motor eastward or westward. That is achieved by the AT89C2051 giving signal to the relay RL1 according to the directives of the programed controller, the relay RL1 will in turn stops the AT89C51 RL7 in order for the motor to turn in clockwise direction there by marking the plate rotate towards eastward depending on how the controller was positioned. On the other hand, the Relay RL2 will receive signal from the 89c2051 controller and stop RL4 thereby making the motor to turn in anti clockwise direction as a result, pulling the panel westward after 6 hours.
4.6 THE SWITCH UNIT
When the circuit is connected to a DC source the switch will now serve as what makes current to flow into the whole circuit and when once it is being switched ON as a result utilizing the supplied dc current to do necessary operation in the circuit.
OPERATION PRINCIPLE when light falls on the sensor (LDR) in the morning at about 6.45, the resistance of the sensor will decrease dramatically thereby allowing light to flow through the base of the transistor Q4 as well, it gets into the base of the other transistor Q9, the flow of current into the base of the transistors will be controlled by the resistor R12 and R14 which are connected in series to them. The sensitivity of the sensor circuit can be controlled by the use of a variable resistor which is connected in series with it. From the transistor Q9, the current gets to the relay (RL5) which acts as an electric switch, at that same point in time, the relay control the current that will be fed to the AT89C51RD2 controller through the regulator. The crystal oscillator which is connected to the controller generates a pulse sine wave which will move in the same frequency as to match with the frequency of the AT89C51RD2 controller which is about 12 million times per seconds. The three 7447 decoders linked to the AT89C51RD2 help in converting the binary coded decimal (BCD) signal of the controller into a readable signal that can be seen through the seven segment display. The reset part of the AT89C51RD2 helps to reset the controller back to its initial memory level which is 0.00 level. While the minute and second part helps to increment or decrement the time. The LED part of the AT89C51RD2 is used to indicate when the panel is been rotated towards east or west direction of the cardinal points. The AT89C2051 microcontroller which links to AT89C51RD2 microcontroller is used to control the Bi-directional movement of the plate (either towards east or towards west) word direction. That is achieved through the help of the relays RL1, RL2, RL3 and RL4. Since sun start from the east at 6:45am and sets at exactly 12:45pm, the light controller circuit put on the whole circuit automatically making the timer to initialize its 6hrs counting sequence. Microcontroller through p3.6 in accordance to the program in its memory Activate the countdown timer in turn activates RL1 and RL4, whereby turning the motor eastward according to how the solar was positioned in order to expose the solar plate to full access to the sun illumination and stop by the eastward limiter. Immediately it is 12:45pm, microcontroller timer drop to 0:00 and activates westward countdown timer through p3.7 then the westward 555 in turn activates RL2 and RL3, whereby turning the motor westward to expose the solar plate to full access to the sun illumination and stop by the western limiter. When the motor is turning eastward, RL1 and RL4 are on at the same time, RL1 is sensor relay that ensures that RL3 is off to avoid RL3 and RL4 oning at the same time, and else there will be heat generation in the circuit which may spoil some components. On the other hand RL2 plays the same roll to switch RL4 off when RL3 is on. Based on the Bi-directional movement of the motor, positive and negative terminals are connected to the motor through RL4 dual pole and the connection are interchanged through RL3 dual pole to westward. These description above, brought about the working (Operational) principle of a microcontroller based sun trackers.

LIGHT MONITOR (SENSOR CIRCUIT)
SUB-CIRCIT 1

AT89C51RD2 MICROCONTROLLER count equ r0 sec equ r1 min equ r2 hour equ r3 var1 equ r4 delay equ r5 buz bit p3.7 org 0000h jmp main
; this timer interupt need 11 machine cycles to execuate so we load timer values according to calculation + 11
; in this way error will be minimum and time for clock will be accurate org 000BH ; timer 0 interrupt mov th0,#3ch mov tl0,#0bbh inc count reti main: clr p3.6 call delay2 setb p3.6 clr buz mov ie,#82H mov sp,#50h mov tmod,#01h ; timer 0 used as a timer in mode 1 (16-bit) mov th0,#3ch ; values for 50 ms delay mov tl0,#0bbh
; let say u r usng 12 MHz oscillator then 12 MHz/12 =1 MHz = 1us
; (65536-xx)*1 us = 50 ms
; (65536-xx) = 50000
; xx = 15536 which is 3cb0 in hex
; calaulated values + 11 for acurate timing
; 15536 + 11 = 15547 which is 3cbb in hex setb tr0 ; start timer to produce delay call load back: cjne count,#20,exit mov count,#0 inc sec jnb buz,skip clr buz skip: cjne sec,#60,exit mov sec,#0 inc min dec th1 mov a,th1 cjne a,#-1, next mov th1,#59 next: cjne min,#60,exit mov min,#0 inc hour dec tl1 mov a,tl1 cjne a,#-1, nxt mov tl1,#05 nxt: cjne hour,#6,exit ; if hour=6 mov hour,#0 ; again hour =0 exit: call display_min call display_hour call check_buz call buttons jmp back load: mov th1,#59 ; minutes mov tl1,#05 ; hour mov count,#0 mov sec,#0 mov min,#0 mov hour,#0 ret display_min: mov a,th1 mov b,#10 div ab ; a= quiotient b= remainder mov p2,a mov p1,b ret display_hour: mov a,tl1 mov b,#10 div ab ; a= quiotient b= remainder mov p0,b ret check_buz: mov a,th1 jnz rev mov a,tl1 jnz rev setb buz ; buzzer on call load rev: ret

buttons: jb int0,nnext call min_set call delay_250 nnext: jb int1,neext call hour_set call delay_250 neext: jb rxd,eexit call load call delay_250 eexit: ret

delay_250: mov delay,#250 ;delay 250ms call delayms mov delay,#250 ;delay 250ms call delayms ret min_set: dec th1 mov a,th1 cjne a,#-1,next1 mov th1,#59 next1: ret

hour_set: dec tl1 mov a,tl1 cjne a,#-1,next2 mov tl1,#05 next2: ret

delayms: mov var1,#230 d: nop nop djnz var1,d djnz delay,delayms ret delay2: ;DELAY OF ONE SECOND MOV TMOD,#01H MOV TH0,#3CH MOV TL0,#0B0H MOV R7,#00H SETB TR0 DEL:JNB TF0,DEL MOV TH0,#3CH MOV TL0,#0B0H CLR TF0 INC R7 CJNE R7,#14H,DEL RET end

:03000000020013E8
:10000B00758C3C758ABB0832C2B61200E5D2B6C2FB
:10001B00B775A882758150758901758C3C758ABB43
:10002B00D28C12006EB8142D78000930B702C2B70B
:10003B00B93C2279000A158DE58DB4FF03758D3B14
:10004B00BA3C127A000B158BE58BB4FF03758B054D
:10005B00BB06027B0012007D120089120093120076
:10006B00A080C2758D3B758B05780079007A007B7B
:10007B000022E58D75F00A84F5A085F09022E58BC2
:10008B0075F00A8485F08022E58D7008E58B70048D
:10009B00D2B7116E2220B2061200C61200BB20B3DB
:1000AB00061200D11200BB20B005116E1200BB224C
:1000BB007DFA1200DC7DFA1200DC22158DE58DB481
:1000CB00FF03758D3B22158BE58BB4FF03758B05F9
:1000DB00227CE60000DCFCDDF822758901758C3C86
:1000EB00758AB07F00D28C308DFD758C3C758AB0D3
:0700FB00C28D0FBF14F122BA
:00000001FF

AT89C2051 MICRO ASSEMBLER SOLAR2

MS-DOS MACRO ASSEMBLER A51 V4.4
OBJECT MODULE PLACED IN SOLAR2.OBJ
ASSEMBLER INVOKED BY: A51 SOLAR2.ASM

LOC OBJ LINE SOURCE

0000 1 org 00h 2
0000 3 main:
0000 75B0FF 4 mov p3,#0ffh
0003 759000 5 mov p1,#00b 6
0006 7 scan:
0006 30B317 8 jnb p3.3,west
0009 30B202 9 jnb p3.2,east
000C 80F8 10 jmp scan 11
000E 12 east:
000E C295 13 clr p1.5
0010 120032 14 call delay
0013 D293 15 setb p1.3
0015 D292 16 setb p1.2
0017 12004F 17 call delay53
001A C292 18 clr p1.2
001C C293 19 clr p1.3
001E 80E6 20 jmp scan 21 22 23
0020 24 west:
0020 C292 25 clr p1.2
0022 120032 26 call delay
0025 D296 27 setb p1.6
0027 D295 28 setb p1.5
0029 12004F 29 call delay53
002C C295 30 clr p1.5
002E C296 31 clr p1.6
0030 80D4 32 jmp scan 33 34 35 36 37
0032 38 delay: ;DELAY OF ONE SECOND
0032 758901 39 MOV TMOD,#01H
0035 758C3C 40 MOV TH0,#3CH
0038 758AB0 41 MOV TL0,#0B0H
003B 7F00 42 MOV R7,#00H
003D D28C 43 SETB TR0
003F 308DFD 44 DEL:JNB TF0,DEL
0042 758C3C 45 MOV TH0,#3CH
0045 758AB0 46 MOV TL0,#0B0H
0048 C28D 47 CLR TF0
004A 0F 48 INC R7
004B BF14F1 49 CJNE R7,#14H,DEL
004E 22 50 REt 51
004F 52 delay53:
004F 7A35 53 mov r2,#53
0051 1132 54 eee:call delay

A51 MICRO ASSEMBLER SOLAR2

LOC OBJ LINE SOURCE

0053 DAFC 55 djnz r2,eee
0055 22 56 ret 57 58 end

SYMBOL TABLE LISTING
------ ----- ------
N A M E T Y P E V A L U E ATTRIBUTES
DEL. . . . C ADDR 003FH A
DELAY. . . C ADDR 0032H A
DELAY53. . C ADDR 004FH A
EAST . . . C ADDR 000EH A
EEE. . . . C ADDR 0051H A
MAIN . . . C ADDR 0000H A
P1 . . . . D ADDR 0090H A
P3 . . . . D ADDR 00B0H A
SCAN . . . C ADDR 0006H A
TF0. . . . B ADDR 0088H.5 A
TH0. . . . D ADDR 008CH A
TL0. . . . D ADDR 008AH A
TMOD . . . D ADDR 0089H A
TR0. . . . B ADDR 0088H.4 A
WEST . . . C ADDR 0020H A

REGISTER BANK(S) USED: 0

ASSEMBLY COMPLETE, NO ERRORS FOUND

CHAPTER FIVE
5.0 RESULT ANALYSIS Hardware and Software portions of the project were separated into stages while developing the overall system. The portions consisted of light detection, motor driver, software tracker and software enhancements. Building and testing smaller sections of the system made the project more manageable and increased efficiency by decreasing debugging time. The testing of the project started with the testing of the power supply unit to ensure that it supplied the required power to the circuit. The motor controller was tested next to ensure that it would rotate in the clockwise, anticlockwise as well as stop positions.
The light dependent resistor was also tested in which its main function was to ON the circuit when it senses a sun rays in the morning and also OFF the circuit when the sun rays goes OFF in the evening/night. The microcontroller was also tested which was programed in such a way that after six hours, it will send a pulse signal to the motor to rotate in either clockwise or anticlockwise direction depending on the direction of the sun. After the whole system unit (electrical are mechanical) had been coupled, the solar elevation sun tracker was tested as a functional unit was found and found to be working.
5.1 PROBLEMS ENCOUNTERED Cost is the major factor when taking into consideration, but not only in the selection of materials employed, but also in the processing of the selected materials
This research, Design and Construction work was very interesting and has broadened our knowledge mostly in the field of another means of power generation that is human friendly.
Though this work was successful, many unexpected problems were encountered during the construction work. Some component were no more in use due to the fact that the idea that was adopted at the initial construction stage did not work. Also In the cause of the initial construction which did not work, some component were also destroyed.
Most of the components were expensive and difficult to obtain. Practical experience or background was not much before embarking on the project, but it led us to make in-depth research form interested services using so many search engines to find out to have means towards providing accurate solar control panel. We also inquire advice from experts in the field to enable us carry out the project and we also came up with same constructive ideas to make the project successful.
TABLE 3: BILL OF QUANTITY
S/NO COMPONENT NUMBER PER PRICE
N TOTAL PRICE
N
1 BC 337 Transistor 2 50 100
2 12 MH3 Crystal oscillator 2 50 100
3 33 Pf capacitor 4 20 80
4 10 UF, 50v supply 1 20 20
5 40 2 10 20
6 SEVEN SEGMENT DISPLAY 3 200 600
7 47K Resistor 1 5 5
8 7447 decoder 3 120 360
9 BC 547 2 50 100
10 12V relay 6 100 600
11 AT89C 51RD2 1 1200 1200
12 DC Motorized actuator 1 4000 4000
13 Battery 2 2300 4600
14 Fuse 1 50 50
15 Switch 1 50 50
16 Vero board 2 50 100
17 Connector Jail 2 150 300
18 Standing 1 6000 6000
19 Ply word 1 300 300
20 LDR 1 50 50
21 1K Resistor 8 5 40
22 10KVR 1 20 20
23 4.7K Resistor 1 5 5
24 AT89C2051 1 1000 1000 TOTAL 19,700
CHAPTER SIX
6.0 RECOMMENDATION AND CONCLUSION
6.1 RECOMMENDATION AND FUTURE WORK The goals of this project where purposely kept within what was believed to be attainable within the allotted timeline. As such, many improvement can be made upon this initial design. That being said, it is felt that this design represents a functioning miniature scale model which could be replicated to a much larger scale.
● The following recommendations are provided as ideas for future expansion of this project.
● Increase the sensitivity and accuracy of tracking by using a different light sensor.
● A phototransistor with an amplification circuit would provide, improve, resolution and better tracking accuracy/precision.
● Utilize a dual-axis design versus a single axis to increase tracking accuracy
6.2 CONCLUSION The project presented a means of controlling a sun tracking array with an embedded microcontroller system, a working software solution for maximizing solar cell output by positioning a solar array at the point of maximum light intensity. This project presents method of searching and tracking the sun and resetting itself for a new day. While the project has limitations, this provides an opportunity for expansion of the current project in future years.

REFERENCE
Chiwetalu B.N (2004), Electronics Concept Material And Devices; Ziks Chuks Press Enugu, Nigeria
Ihemadu O.C (2003), Digital Electronics Concept And
Application; Cheston Ltd, Enugu, Nigeria.
Joe-Air Jiang, Toong-Liang-Tung Hsiao and Chia-Hong Chen, (2005). Maximum Power Tracking for Photovoltiae
Kalogirous S. (2002). Design of a fuzzy single-axis sun tracking _ controller. Int J. Renew Energy Eng, 4(2).
Runsheng Tang Tong Wu, (2001). Optimal hit-angles for solar collectors used in China Applied Energy 79, pp. 239 power Systems, Tam Kang Journal of science and engineering, Vol. 8, No 2, pp 147-153
Runsheng Tang, Tong Wu, (2004). Optimal hit-angles for solar collectors used in china, Applied Energy 79, pp 239-249,
Sclater. N. (2007). Mechanisms and Mechanical; Devices Sources Book, _ 4th Edition, 25, McGraw-\Hill Theraja A. K and Theraja B. L (2004); Electrical Technology; S. Chand, new Delhi India http://en.wilipedia.org http://www.time.anddate.com http://solardat.uoregon.edu/sunchartprogram.htmi http://www.electronics.howstuffworks.com