solar tracker report final

7/28/2019 Solar Tracker Report Final

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ABSTRACT

The following document details the research and development of an

Automatic Solarradiation tracker. Fossil fuels are a relatively short-term energy

source; consequently,the uses of alternative sources such as solar energy are

becoming more wide spread.To make solar energy more viable, the efficiency of

solar array systems must be maximized. A feasible approach to maximizing the

efficiency of solar array systemsis sun tracking. Proposed in this report is a system

that controls the movement of a solar array so that it is constantly aligned towards

the direction of the sun.Solar modules are devices that cleanly convert sunlight into

electricity and offer a practical solution to the problem of power generation in

remote areas. The solartracker designed and constructed in this project offers a

reliable and affordable method of aligning a solar module with the sun in order to

maximize its energy output.

Automatic Sun Tracking System is a hybrid hardware/software prototype,

which automatically provides best alignment of solar panel with the sun, to get

maximum output (electricity).


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1. INTRODUCTION

Renewable energy solutions are becoming increasingly popular.

Photovoltaic (solar)systems are but one example. Maximizing power output from a

solar system is desirable to increase efficiency. In order to maximize power output

from the solar panels, one needs to keep the panels aligned with the sun. As such, a

means of tracking the sun is required. This is a far more cost effective solution than

purchasing additional solar panels. It has been estimated that the yield from solar

panels can be increased by 30 to 60 percent by utilizing a tracking system instead of

a stationary array [1]. This project develops an automatic tracking system which

will keep the solar panels aligned with the sun in order to maximize efficiency.

This paper begins with presenting background theory in light sensors and

stepper motorsas they apply to the project. The paper continues with specific

design methodologiespertaining to photocells, stepper motors and drivers,

microcontroller selection, voltage regulation, physical construction, and a

software/system operation explanation. The paper concludes with a discussion of

design results and future work.


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2. Background Information

This section presents background information on the main subsystems of the

project. Specifically, this section discusses photocell and stepper motor theory in

order to provide a better understanding as to how they relate to the solar tracker.


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PhotoconductorTime

ConstantSpectral Band

Cadmium Sulphide CdS 100 milli sec 0.47 to 0.72 um

Cadmium Selenide

CdSe10 milli sec 0.6 to 0.77 um

Lead Sulphide PbS 410 micro sec 1 to 3.2 um

Lead Selenide PbSe10.2 micro

sec1.52 to 4.2 um

Now when the device is dark, its resistance is called as dark resistance. This

resistance is typically of the order of 1013 ohms. When light falls on it, its resistance

decreases up to several kilo ohms or even hundreds of ohms, depending on the

intensity of light, falling on it.

The spectral response characteristics of two commercial cells were compared

in our laboratory. And we found that there is almost no response to the radiation of

a wavelength which was shorter than 300nm. It was very interesting to note that the


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Cadmium Sulphide cell has a peak response nearer or within the green color of the

spectrum within a range of 520nm. Thus it can be used nearer to the infra-red

region up to 750nm. It was found that the maximum response ofCadmium

Sulphoselenide is in the yellow-orange range at 615nm and also it can be used in

the infra-red region up to about 970nm.

2.1 INTRODUCTION TO STEPPER MOTOR

The stepper motor is an electromagnetic device that converts digital pulses

into mechanical shaft rotation. The shaft or spindle of a stepper motor rotates in

discrete step increments when electrical command pulses are applied to it in the

proper sequence. The sequence of the applied pulses is directly related to the

direction of motor shafts rotation. The speed of the motor shafts rotation is directly

related to the frequency of the input pulses and the length of rotation is directly

related to the number of input pulses applied. Many advantages are achieved using

this kind of motors, such as higher simplicity, since no brushes or contacts are

present, low cost, high reliability, high torque at low speeds, and high accuracy of

motion. Many systems with stepper motors need to control the acceleration/

deceleration when changing the speed.


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Bipolar v/s. Unipolar Stepper Motors

The two common types of stepper motors are the bipolar motor and the

unipolar motor. The bipolar and unipolar motors are similar, except that the

unipolar has a center tap on each winding. The bipolar motor needs current to be

driven in both directions through the windings, and a full bridge driver is needed

.The center tap on the unipolar motor allows a simpler driving circuit, limiting the

current flow to one direction. The main drawback with the unipolar motor is the

limited capability to energize all windings at any time, resulting in a lower torque

compared to the bipolar2.2 Bipolar v/s. Unipolar Stepper Motors

The two common types of stepper motors are the bipolar motor and the

unipolar motor. The bipolar and unipolar motors are similar, except that the


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unipolar has a center tap on each winding. The bipolar motor needs current to be

driven in both directions through the windings, and a full bridge driver is needed

.The center tap on the unipolar motor allows a simpler driving circuit, limiting the

current flow to one direction. The main drawback with the unipolar motor is the

limited capability to energize all windings at any time, resulting in a lower torque

compared to the bipola


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STEPPER MOTOR CONNECTION DIAGRAM

The wires from the Logic PCB connector to the stepper motor are as follows


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STEPPER MOTOR DRIVER

The ULN2003 / MC1413 is a 7-bit 50V 500mA TTL-input NPN darlington

driver.This is more than adequate to control a four phase unipolar stepper motor

such as the KP4M4-001.

It is recommended to connect a 12v zener diode between the power supply and

VDD(Pin 9) on the chip, to absorb reverse (or "back") EMF from the magnetic field

collapsing when motor coils are switched off.


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It has been seen that out of the five wires two are grouped as common. The other

four are the windings that have to give supply to. Major crux here is to identify the

common line. Just take the multimeter and check the resistance between the

wires.Hold one wire a common and it must bear a resistance of 75 ohms with all the

other wires then that is the common wire. 2.5 Connection of the Circuit:


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Use Microcontroller PIC16F877A to give +5v supply to pins a,b,c,d one by one

thats:

a=5v,b=0,c=0,d=0

a=0,b=5v,c=0,d=0

a=0,b=0,c=5v,d=0

a=0,b=0,c=0,d=5v

Then the motor will run.

2.6 Unipolar Stepper Motor:

In the construction of unipolar stepper motor there are four coils. One end of

each coil is tide together and it gives common terminal which is always connected

with positive terminal of supply. The other ends of each coil are given for interface.

Specific colour code may also be given. Like in this motor orange is first coil (L1),

brown is second (L2), yellow is third (L3), black is fourth (L4) and red for common

terminal. By means of controlling a stepper motor operation we can

Increase or decrease the RPM (speed) of it

Increase or decrease number of revolutions of it


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Change its direction means rotate it clockwise or anticlockwise

To vary the RPM of motor we have to vary the PRF (Pulse Repetition

Frequency).Number of applied pulses will vary number of rotations and last to

change direction we have to change pulse sequence.

So, all these three things just depend on applied pulses. Now there are three

different modes to rotate this motor

1. Single coil excitation

2. Double coil excitation

3. Half step excitation


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In half step excitation mode motor will rotate at half the specified given step

resolution. Means if step resolution is 1.8 degree then in this mode it will be 0.9

degree. Step resolution means on receiving on 1 pulse motor will rotate that

muchdegree. If step resolution is 1.8 degree then it will take 200 pulses for motor to

compete 1 revolution (360 degree).

SPECIFICATION OF THE STEPPER MOTOR:

Max rated current per coil: 0.75 Ampere, unipolar, 6 wires The motors rotation has

several direct relationships to these applied input pulses. The sequence of the

applied pulses is directly related to the direction of motor shafts rotation. The speed

of the motor shafts rotation is directly related to the frequency of the input pulses

and the length of rotation is directly related to the number of input pulses applied.

2.7 STEPPER MOTOR ADVANTAGES AND DISADVANTAGES

Advantages:

1. The rotation angle of the motor is proportional to the input pulse.

2. The motor has full torque at standstill (if the windings are energized)

3. Precise positioning and repeatability of movement since good stepper motors

have an accuracy of 35% of a step and this error is non cumulative from one step

to the next.


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4. Excellent response to starting/ stopping/reversing.

5. Very reliable since there are no contact brushes in the motor. Therefore, the life

of the motor is simply dependant on the life of the bearing.

6. The motors response to digital input pulses provides open-loop control, making

the motor simpler and less costly to control.

7. It is possible to achieve very low speed synchronous rotation with a load that is

directly coupled to the shaft.

8. A wide range of rotational speeds can be realized as the speed is proportional to

the frequency of the input pulses.

Disadvantages:

1. Resonances can occur if not properly controlled.

2. Not easy to operate at extremely high speeds.

2.8 Open Loop Operation

One of the most significant advantages of a stepper motor is its ability to be

accurately controlled in an open loop system. Open loop control means no feedback

information about position is needed. This type of control eliminates the need for


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expensive sensing and feedback devices such as optical encoders. Position of

stepper motor is known simply by keeping track of the input step pulses.

2.9 Stepper Motor Types

There are three basic stepper motor types. They are:

Variable-reluctance

Permanent-magnet

Hybrid

2.9.1 Variable-reluctance (VR)

This type of stepper motor has been around for a long time. It is probably the easiest

to understand from a structural point of view. This type of motor consists of a soft

iron multi-toothed rotor and a wound stator. When the stator windings are energized

with DC current the poles become magnetized. Rotation occurs when the rotor teeth


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are attracted to the energized stator poles.

2.9.2 Permanent Magnet (PM)

Often referred to as a tin can or canstock motor the permanent magnet step

motor is a low cost and low resolution type motor with typical step angles of 7.5 to

15. (48 24 steps/revolution) PM motors as the motor name implies have

permanent magnets added to the motor structure. The rotor no longer has teeth as

with the VR motor. Instead the rotor is magnetized with alternating north and south

poles situated in a

straight line parallel to the rotor shaft. These magnetized rotor poles provide an

increased magnetic flux intensity and because of this the PM motor exhibits

improved torque characteristics when compared with the VR type.


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2.9.3

Hybrid (HB)

The hybrid stepper motor is more expensive than the PM stepper motor but

provides better performance with respect to step resolution, torque and speed.

Typical step angles for the hybrid stepper motor, range from 3.6 to 0.9 (100400

steps per revolution). The hybrid stepper motor combines the best features of both

the PM and VR type stepper motors. The rotor is multi-toothed like the VR motor

and contains an


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axially magnetized concentric magnet around its shaft. The teeth on the rotor

provide an even better path which helps guide the magnetic flux to preferred

locations in the airgap. This further increases the detent, holding and dynamic

torque characteristics of the motor when compared with both the VR and PM types.

2.10

Applications of Stepper Motor

A stepper motor can be a good choice whenever controlled movement is required.

They can be used to advantage in applications where you need to control rotation

angle, speed, position and synchronism. Because of the inherent advantages listed

previously, stepper motors have found their place in many different applications.


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Some of these include printers, plotters, high end office equipment, hard disk

drives, medical equipment, fax machines, automotive and many more.

2.11 The Rotating Magnetic Field

When a phase winding of a stepper motor is energized with current a magnetic flux

is developed in the stator. The direction of this flux is determined by the Right

Hand Rule which states:

If the coil is grasped in the right hand with the fingers pointing in the direction of

the current in the winding (the thumb is extended at a 90 angle to the fingers), then

the thumb will point in the direction of the magnet ic field. The rotor then aligns


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itself so that the flux opposition is minimized. In this case the motor would rotate

clockwise so that its south pole aligns with the north pole of the stator and its north

pole aligns withthe south pole of stator. To get the motor to rotate we must provide

a sequence of energizing the stator windings in such a fashion that provides a

rotating magnetic flux field which the rotor follows due to magnetic attraction.

2.12 Torque Generation

The torque produced by a stepper motor depends on several factors:

The step rate

The drive current in the windings

The drive design or type

In a stepper motor a torque is developed when the magnetic fluxes of the rotor and

stator are displaced from each other. The stator is made up of a high permeability

magnetic material. The presence of this high permeability material causes the

magnetic flux to be confined for the most part to the paths defined by the stator

structure in the same fashion that currents are confined to the conductors of an

electronic circuit. This serves to concentrate the flux at the stator poles. The torque


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output produced by the motor is proportional to the intensity of the magnetic flux

generated when the winding is energized.

The basic relationship which defines the intensity of the magnetic flux is defined

by:

H = (N * i) / l

Where:

N = Number of winding turns

i = Current

H = Magnetic field intensity

l = Magnetic flux path length

This relationship shows that the magnetic flux intensity and consequently the torque

is proportional to the number of winding turns and the current and inversely

proportional to the length of the magnetic flux path. It has been seen that the same

frame size stepper motor could have very different torque output capabilities simply

by changing the winding parameters.


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2.13 Phases, Poles and Stepping Angles

Usually stepper motors have two phases, but three- and five-phase motors also

exist. A bipolar motor with two phases has one winding/phase and a unipolar motor

has one winding, with a center tap per phase. Sometimes the unipolar stepper motor

is referred to as a four phase motor, even though it has only two phases. Motors

that have two separate windings per phase also existthese can be driven in either

bipolar or unipolar mode. A pole can be defined as one of the regions in a

magnetized body where the magnetic flux density is concentrated. Both the rotor

and the stator of a step motor have poles.

In reality several more poles are added to both the rotor and stator structure in order

to increase the number of steps per revolution of the motor, or in other words to

provide a smaller basic (full step) stepping angle. The permanent magnet stepper

motor contains an equal number of rotor and stator pole pairs. Typically the PM

motor has 12 pole pairs. The stator has 12 pole pairs per phase. The hybrid type

stepper motor has a rotor with teeth. The rotor is split into two parts, separated by a

permanent magnet making half of the teeth south poles and half north poles. The

number of pole pairs is equal to the number of teeth on one of the rotor halves. The

stator of a hybrid


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CHAPTER 2

AT89C51

Description

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with

4Kbytes of Flash programmable and erasable read only memory (PEROM). The

deviceis manufactured using Atmels high-density nonvolatile memory technology

and is compatible with the industry-standard MCS-51 instruction set and pinout.

The on-chipFlash allows the program memory to be reprogrammed in-system or by

a conven-tional nonvolatile memory programmer. By combining a versatile 8-bit

CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful

microcomputer which provides a highly-flexible and cost-effective solution to many

embedded control applications.


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Pin Configurations


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Block Diagram


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AT89C51 Application circuits


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The AT89C51 provides the following standard features: 4Kbytes of Flash, 128

bytes of RAM, 32 I/O lines, two 16-bittimer/counters, a five vector two-level

interrupt architecture,a full duplex serial port, on-chip oscillator and clock cir-

cuitry. In addition, the AT89C51 is designed with static logicfor operation down to

zero frequency and supports twosoftware selectable power saving modes. The Idle

Modestops the CPU while allowing the RAM, timer/counters,serial port and

interrupt system to continue functioning. ThePower-down Mode saves the RAM

contents but freezesthe oscillator disabling all other chip functions until the

nexthardware reset.


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Pin Description

VCC

Supply voltage.

GND

Ground.

Port 0

Port 0 is an 8-bit open-drain bi-directional I/O port. As anoutput port, each pin can

sink eight TTL inputs. When 1 sare written to port 0 pins, the pins can be used as

high-impedance inputs.Port 0 may also be configured to be the multiplexed low-

order address/data bus during accesses to external pro-gram and data memory. In

this mode P0 has internal pullups.Port 0 also receives the code bytes during Flash

program-ming, and outputs the code bytes during program verification. External

pullups are required during program verification.

Port 1

Port 1 is an 8-bit bi-directional I/O port with internal pullups.The Port 1 output

buffers can sink/source four TTL inputs.When 1s are written to Port 1 pins they are

pulled high by the internal pullups and can be used as inputs. As inputs,Port 1 pins

that are externally being pulled low will source current (IIL) because of the internal


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pullups. Port 1 also receives the low-order address bytes during Flash programming

and verification.

Port 2

Port 2 is an 8-bit bi-directional I/O port with internal pullups.The Port 2 output

buffers can sink/source four TTL inputs.When 1s are written to Port 2 pins they are

pulled high by the internal pullups and can be used as inputs. As inputs, pulse is

skipped during each access to external Data Memory. If desired, ALE operation can

be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active

only during a MOVX or MOVC instruction. Otherwise, the pin isweakly pulled

high. Setting the ALE-disable bit has noeffect if the microcontroller is in external

execution mode.

PSEN

Program Store Enable is the read strobe to external pro-gram memory. When the

AT89C51 is executing code from external pro-gram memory, PSEN is activated

twice each machine cycle, except that two PSEN activations are skipped during

each access to external data memory.


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EA/VPP

External Access Enable. EA must be strapped to GND inorder to enable the device

to fetch code from external pro-gram memory locations starting at 0000H up to

FFFFH.Note, however, that if lock bit 1 is programmed, EA will beinternally

latched on reset. EA should be strapped to VCC for internal program

executions.This pin also receives the 12-volt programming enable volt-age (VPP)

during Flash programming, for parts that require 12-volt VPP.

PSEN

Program Store Enable is the read strobe to external pro-

gram memory. When the AT89C51 is executing code from external pro-gram

memory, PSEN is activated twice each machine cycle, except that two PSEN

activations are skipped during each access to external data memory.

EA/VPP

External Access Enable. EA must be strapped to GND inorder to enable the device

to fetch code from external pro-gram memory locations starting at 0000H up to

FFFFH.Note, however, that if lock bit 1 is programmed, EA will beinternally

latched on reset. EA should be strapped to VCC for internal


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programexecutions.This pin also receives the 12-volt programming enable volt-age

(VPP) during Flash programming, for parts that require

12-volt VPP.


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Flash Programming and Verification Characteristics

T = 0C to 70C, V = 5.0 10%


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A D C

3.6 Introduction to ADC

The analog-to-digital (A/D) converter module can have up to eight analog inputs for

adevice. The analog input charges a sample and hold capacitor. The output of the

sample and hold capacitor is the input into the converter. The converter then

generates a digital result of this analog level via successive approximat ion. This

A/Dconversion, of the analog input signal, results in a corresponding 10-bit digital

number. The analog reference voltages (positive and negative supply) are software

selectable to either the devices supply voltages (AVDD, AVss) or the voltage level

on the AN3/VREF+ and AN2/VREFpins. The A/D converter has a unique feature

of being able to operate while the device is in SLEEP mode.

DESCRIPTION

The ADC0808, ADC0809 data acquisition component is a monolithic CMOS

device with an 8-bit analog-to-digitalconverter, 8-channel multiplexer and

microprocessor compatible control logic. The 8-bit A/D converter uses successive

approximation as the conversion technique. The converter features a high

impedance chopper stabilized comparator, a 256R voltage divider with analog

switch tree and a successive approximation register.The 8-channel multiplexer can

directly access any of 8-single-ended analog signals.The device eliminates the need


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for external zero and full-scale adjustments. Easy interfacing to microprocessors is

provided by the latched and decoded multiplexer address inputs and latched TTL

TRI-STATE outputs.The design of the ADC0808, ADC0809 has been optimized by

incorporating the most desirable aspects of several A/D conversion techniques. The

ADC0808, ADC0809 offers high speed, high accuracy, minimal temperature

dependence, excellent long-term accuracy and repeatability, and consumes minimal

power.

These features make this device ideally suited to applications from process and

machine control to consumer andautomotive applications. For 16-channel

multiplexer with common output (sample/hold port) see ADC0816 datasheet.

(SeeAN-247formore information.

)


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BLOCK DIAGRAM


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The successive approximation register (SAR) performs 8 iterations to approximate

the input voltage. For anySAR type converter, n-iterations are required for an n-bit

converter. Figure 4 shows a typical example of a 3-bit converter. In the ADC0808,

ADC0809, the approximation technique is extended to 8 bits using the

256Rnetwork.

The A/D converter's successive approximation register (SAR) is reset on the

positive edge of the start conversion start pulse. The conversion is begun on the

falling edge of the start conversion pulse. A conversion in process will be

interrupted by receipt of a new start conversion pulse. Continuous conversion may

be accomplished by tying the end-of-conversion (EOC) output to the SC input. If

used in this mode, an external start conversion pulse should be applied after power

up. End-of-conversion will go low between 0 and 8 clock pulses after the rising

edge of start conversion.

The most important section of the A/D converter is the comparator. It is this section

which is responsible for the ultimate accuracy of the entire converter. It is also the

comparator drift which has the greatest influence on the repeatability of the device.

A chopper-stabilized comparator provides the most effective method of satisfying

all the converter requirements.


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The chopper-stabilized comparator converts the DC input signal into an AC signal.

This signal is then fed through a high gain AC amplifier and has the DC level

restored. This technique limits the drift component of the amplifier since the drift is

a DC component which is not passed by the AC amplifier. This makes the entire

A/D converter extremely insensitive to temperature, long term drift and input offset

errors.


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TIMING DIAGRAM


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OPERATION

RATIOMETRIC CONVERSION

The ADC0808, ADC0809 is designed as a complete Data Acquisition System

(DAS) for ratiometric conversionsystems. In ratiometric systems, the physical

variable being measured is expressed as a percentage of full-scalewhich is not

necessarily related to an absolute standard. The voltage input to the ADC0808 is

expressed by the

equation

VIN= Input voltage into the ADC0808

Vfs= Full-scale voltage

VZ= Zero voltage

DX= Data point being measured

DMAX= Maximum data limit

DMIN= Minimum data limit (1)

A good example of a ratiometric transducer is a potentiometer used as a position

sensor. The position of the wiper is directly proportional to the output voltage

which is a ratio of the full-scale voltage across it. Since the data is represented as a


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proportion of full-scale, reference requirements are greatly reduced, eliminating a

large source of error and cost for many applications. A major advantage of the ADC

0808, ADC0809 is that the input voltage range is equal to the supply range so the

transducers can be connected directly across the supply and their outputs connected

directly into the multiplexer inputs, (Figure 11).Ratiometric transducers such as

potentiometers, strain gauges, thermistor bridges, pressure transducers, etc.,are

suitable for measuring proportional relation ships; however, many types of

measurements must be referred to an absolute standard such as voltage or current.

This means a system reference must be used which relates the full-scale voltage to

the standard volt. For example, if VCC=VREF=5.12V, then the full-scale range is

divided into 256 standard steps. The smallest standard step is 1 LSB which is then

20 mV.

RESISTOR LADDER LIMITATIONS

The voltages from the resistor ladder are compared to the selected into 8 times in a

conversion. These voltages are coupled to the comparator via an analog switch tree

which is referenced to the supply. The voltages at the top, center and bottom of the

ladder must be controlled to maintain proper operation.The top of the ladder,

Ref(+), should not be more positive than the supply, and the bottom of the ladder,

Ref(), should not be more negative than ground. The center of the ladder voltage

must also be near the center of the supply because the analog switch tree changes


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from N-channel switches to P-channel switches. These limitations are automatically

satisfied in ratiometric systems and can be easily met in ground referenced

systems.Figure 12 shows a ground referenced system with a separate supply and

reference. In this system, the supply must be trimmed to match the reference

voltage. For instance, if a 5.12V is used, the supply should be adjusted to the same

voltage within 0.1V.

The ADC0808 needs less than a milliamp of supply current so developing the

supply from the reference is readily accomplished. In Figure 13 a ground referenced

system is shown which generates the supply from the reference. The buffer shown

can be an op amp of sufficient drive to supply the milliamp of supply current and

the desired bus drive, or if a capacitive bus is driven by the outputs a large capacitor

will supply the transient supply current as seen in Figure 14. The LM301 is over

compensated to insure stability when loaded by the 10 F output capacitor.The top

and bottom ladder voltages cannot exceed VCC and ground, respectively, but they

can be symmetrically less than VCC and greater than ground. The center of the


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ladder voltage should always be near the center of the supply. The sensitivity of the

converter can be increased, (i.e., size of the LSB steps decreased) by using a

symmetrical reference system. In Figure 15, a 2.5V reference is symmetrically

centered about VCC/2 since the same current flows in identical resistors. This

system with a 2.5V reference allows the LSB bit to be half the size of a 5V

reference system.


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CONVERTER EQUATIONS

The transition between adjacent codes N and N+1 is given by:

The center of an output code N is given by:

The output code N for an arbitrary input are the integers within the range:

Where:

VIN=Voltage at comparator input

VREF(+)=Voltage at Ref(+)

VREF()=Voltage at Ref()

VTUE=Total unadjusted error voltage (typically

VREF(+)512)

LCD

4.6 LCD

LCD is used in our proposed scheme to display the values of in-circuit current.

Forsimulation purpose, we can use LCD in a 4-bit Mode. For that, we require only

fourd ata lines to be connected to the four port pins of PIC and three control signals

to control the data flow and display.


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LCD Pin Diagram:

BCM LCD Module

Precautions in use of LCD Modules

2.1. Avoid applying excessive shocks to the module or making any alterations or

modifications to it.

2.2. Dont make extra holes on the printed circuit board, modify its shape or change

the

components of LCD module.

2.3. Dont disassemble the LCD module.

2.4. Dont operate it above the absolute maximum rating.


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2.5. Dont drop, bend or twist LCD.

2.6. Soldering: only to the I/O terminals.

2.7. Please storage in anti-static electricity container and clean environment.


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3. General Specification

4. Absolute Maximum Rating


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4. Electrical Characteristics


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7. Interface Pin Function


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8. Contour Drawing and Block Diagram


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11. Instruction Table

12. Timing Characteristic


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2.1 Write Mode Timing Diagram

12.2 Read Mode Timing Diagram


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CIRCUIT DIAGRAM


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WORKING

The above fighure shows that they are 2 Light Depending Resistance (LDR)

are place in the solar panal with diagonal shape. The LDR is produced the intensity

is goes to infinity then the intensity is move to ADC. The ADC is converted to the

intensity and give them 89C51MCIC . The out put of the intensity to be display

with the help of 16/2 LCD display.At the same time Micro contol to get the

intensity to transffered stepper motor that intensity is used to the base of stepper

motor is rotate it is helped to equal intensity comes on the LDR.

LDR

LDR

A

D

C

89C51

MC

DISPLAY

M

OTOR(Drine)

Stepper Motor


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PROGRAM

RS EQU P0.5

EN EQU P0.4

START1 EQU P1.2

EOC EQU P1.3

ADD_A EQU P1.4

ADD_B EQU P1.5

ADD_C EQU P1.6

ALE EQU P1.7

BUZZER EQU P2.4

INCREMENT EQU P2.5

DECREMENT EQU P2.6

MENU_BUTTON EQU P2.7

TRESOLD EQU 20H

SENSE1 EQU 21H


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SENSE2 EQU 22H

DIFFERENCE EQU 23H

STEPPER_DIRECTION EQU 24H

;--------------------------------------------------------------------------

ORG 00H

sJMP MAIN

ORG 30H

;----------------------------------------------------------------------------

MAIN: CLR BUZZER

MOV A,#0H

ANL A,#0FH

ANL P2,#0F0H


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ORL P2,A

ACALL LCD_INIT

;INITIALIZE LCD

MOV SP,#10H

MOV TRESOLD,#5H

MOV DIFFERENCE,#0H

CLR STEPPER_DIRECTION

MOV SENSE1,#0H

MOV SENSE2,#0H

ACALL INIT_MSG ;DISPLAY

PROJECT DETAILS

mov r0,#3h

acall buz

MOV A,#01H

ACALL CMD

ACALL THRESOLD_SET


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;{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{{

{{{{{{{{{{{{{{{{

RUNNING: ACALL ADC_READ

ACALL DISP_SENSOR

ACALL COMPARISON

ACALL DISP_DIFFERENCE

ACALL TRESOLD_CHK

JB MENU_BUTTON,KJ

mov r0,#2h

acall buz

ACALL THRESOLD_SET

KJ: JB INCREMENT,JK

GH: LCALL RIGHT

JNB INCREMENT,GH


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JK: JB DECREMENT,RUNNING

HG: LCALL LEFT

JNB DECREMENT,HG

SJMP RUNNING

;-------------------------------------------------------------------------------

INIT_MSG: ACALL LCD_INIT

MOV DPTR,#MESSAGE1

ACALL DATA_DISPLAY

MOV A,#0C0H

ACALL CMD

MOV DPTR,#MESSAGE2

ACALL DATA_DISPLAY

ACALL DELAY1


64/90


65/90

C1: CLR A

MOVC A,@A+DPTR

JZ DATA_DISPLAY

ACALL CMD

INC DPTR

SJMP C1

;"""""""""""""""""""""""""""""""""""""""""""""""""""""""""

DATA_DISPLAY: PUSH ACC

D1: CLR A

MOVC A,@A+DPTR

JZ EXIT

ACALL DAT

INC DPTR

SJMP D1

;>


66/90

CMD:

CLR RS

ACALL LO

RET

;>< ;8-BIT CODE

IS SPLIT INTO TWO 4-BIT NIBBLES.

MOV R7,A

ANL A,#0F0H

SWAP A

ANL P0,#0F0H

ORL P0,A

CALL ENABLE

MOV A,R7

ANL A,#0FH

ANL P0,#0F0H

ORL P0,A


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CALL ENABLE

RET

ENABLE: ;>< ;GIVE

HIGH-TO-LOW PULSE AT ENABLE PIN

SETB EN

CALL DELAY

CLR EN

RET

;>


72/90

CHK3: JB DECREMENT,CHK4

setb buzzer

DEC A

CJNE A,#0,OK4

MOV A,#250

;>

solar tracker report final

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