light seeking robot report

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GOVERNMENT ENGINEERING COLLEGE IDUKKI

PAINAVU 685 603

LIGHT SEEKING ROBOT MINI PROJECT REPORT

Submitted by

JISMOL JOSEPH (Reg.no:12004755) KEERTHI V K (Reg. no:12004758)

TEENU JOSEPH (Reg. no:12004781) VISHNU K (Reg. no:12004789)

In partial fulfillment for the award of the degree

of

BACHELOR OF TECHNOLOGY

IN

ELECTRONICS AND COMMUNICATION ENGINEERING

MAHATMA GANDHI UNIVERSITY

MAY, 2015

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GOVERNMENT ENGINEERING COLLEGE IDUKKI

PAINAVU 685 603

DEPARTMENT OF

ELECTRONICS AND COMMUNICATION ENGINEERING

BONAFIDE CERTIFICATE

This is to certify that the project report entitled “ LIGHT SEEKING ROBOT” is a

bonafide record of the paper presented byJISMOL JOSEPH (12004755),

KEERTHI V K (12004758), TEENU JOSEPH (12004781), VISHNU

K(12004789) during their sixth semester in partial fulfillment of the requirement

for the award of B-Tech Degree in Electronics & Communication Engineering of

Mahatma Gandhi University, Kottayam, Kerala.

PROJECT GUIDES HEAD OF THE DEPARTMENT Ms. NELSA ABRAHAM Asst.Prof.ECE Mr. SUNIL RAJ Asst.Prof.ECE INTERNAL EXAMINER EXTERNAL EXAMINER

…….…………….. …………………….

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DECLARATION

I hereby declare that the project titled LIGHT SEEKING ROBOT being

submitted in partial fulfillment for the award of B.Tech degree is the original work

carried out by me. It has not formed the part of any other thesis submitted for

award of any degree or diploma, either in this or any other University.

(Signature of the Candidate)

NAME

Register No: NU

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ACKNOWLEDGEMNT We give all honor and praise to the LORD who gave us wisdom and enabled us to complete this project successfully.

We express our heartfelt thanks to Dr. J. David, Principal, Government Engineering College, and Idukkifor granting us permission to do the project.

We express our sincere thanks to our head of the department Prof.K R Ramesh Babu and project guide Ms Nelsa Abraham and Mr Sunil Raj for their valuable advice and guidance.

We also express our gratitude and thanks to all our teachers and other faculty members of the department of Electronics and Communication,Government Engineering College, Idukki for their sincere and friendly cooperation in completing this project.

We are extremely grateful to our parents for their silent prayer.

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ABSTRACT

It is a robot that senses the light and follows it. A user can shine a flash light

at its front and it will respond by following the light source. This robot uses a

micro controller for processing the sensor readings and responds by controlling the

motors and it can also be designed without using micro controller. So basically it is

a robot that responses according to light.

In this case, light source is the object and the Seeker BOT is moving towards

it by comparing the light intensity on left and right sides.

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TABLE OF CONTENTS

ACKNOWLEDGEMENTS ABSTRACT LIST OF FIGURES CHAPTER 1. INTRODUCTION …………………………………07 CHAPTER 2. SYSTEM DESIGN 2.1 BLOCK DIAGRAM ………………………………08 2.2 BLOCK DESCRIPTION …………………………..09 2.3 CIRCUIT DIAGRAM …………………………..…14

2.4 WORKING …………………………………..….…16 CHAPTER 3. PCB FABRICATION……………………………….17 3.1 COMPONENT LAYOUT ………………………...20 3.2 PCB LAYOUT …………………………….….…....21 . CHAPTER 4. CONCLUSION ……………………………….…….22

REFERENCE ……………………………………………………….23 APPENDIX……………………………………………….24

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CHAPTER 1

INTRODUCTION

The light following robot is a mobile machine which is capable of detecting

and following the light source on the traveling path. It is developed without the

help of a micro-controller for providing easier connections and understanding of

the circuit. It requires fewer numbers of electronic components and very cost-

effective as well.

The concept of this light following robot is very simple. It includes two

LDR’s, one on the right and other on the left. When the light falls on the right

LDR, the robot will move on the right side. Similarly, the robot will move on the

left side when the light falls on the left LDR.

The further information about the project is given in the following

chapters.Chapter 2 explains the block level description of the system, it includes

high pass filter, amplifier, comparator, and peak detector blocks. Chapter 3

includes the PCB design general steps, and the specification of op-amp lm324. The

4th chapter deals with the entire working of the system.

The last chapter includes the application and future aspects of our project.

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CHAPTER 2

SYSTEM DESIGN

2.1 BLOCK DIAGRAM

Figure 2.1 shows the major block diagram of light seeking robot which

includes two sensors to detect light intensity, two motors to drive the robot and a

5v battery.

PCB&BATTERY

SENSOR

SENSOR

MOTOR

MOTOR

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2.2 BLOCKDESCRIPTION

POWER SUPPLY UNIT

The power supply unit consists of voltage regulator, a 5V dc voltage

regulator using 7805 which supplies a steady state regulated and low ripple pure

5V dc for the proper functioning of the entire circuitry. The positive power supply

is passed to the IN of IC 7805(1), and sent out through the OUT(3). The negative

power supply is sent to the GND(2) connection of IC 7805. In between, two

capacitors(C1 & C2) are connected to the IN and OUT of IC 7805 respectively. As

a result of this process,5V of current is obtained.

SENSOR CIRCUIT

The sensor circuit consists of the following components

• IC LM 358

• LDR

• RESISTORS

• POTENTIO METER

• LED

• L293d

First part of the circuit is a light searching sensor wired around the popular Op-

Amp LM358N (U1), which is an 8-pin IC having two inbuilt op-amps. Here the

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two op-amps are configured in comparator mode.I.e. the reference voltage is set at

the inverting input pin (-), and then it is compared with the input at non-inverting

(+) input pin (reference voltage at inverting input pin can be set with the help of

associated pot meter). When voltage at non-inverting input pin exceeds this

reference voltage, output of the comparator goes high (H), otherwise it remains in

low (L) state. 2-channel output from U1 is fed to the inputs of the integrated motor

driver L293D (U2), which is an easy-to-use 16-pin IC capable of driving two dc

motors at a time in clockwise (CW) and counterclockwise (CCW) direction

individually.

MOTOR DRIVER

Here gear motor is used for controlling the movement of the vehicle. A motor is

a device that translates electrical signal into mechanical movement. To control the

rotation of the motor here we uses L293D.

L293D is a typical Motor driver or Motor Driver IC which allows DC motor

to drive on either direction. It is a 16-pin IC which can control a set of two DC

motors simultaneously in any direction. It means control of two DC motor with a

single L293D IC. It is a Dual H-bridge Motor Driver integrated circuit (IC).

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PIN FUNCTION NAME

1 Enable pin for Motor 1; active high Enable 1,2

2 Input 1 for Motor 1 Input 1

3 Output 1 for Motor 1 Output 1

4 Ground (0V) Ground




8 Supply voltage for Motors; 9-12V (up to

36V)

vcc 2

9 Enable pin for Motor 2; active high Enable 3,4






15 Input2 for Motor 1 Input 4

16 Supply voltage; 5V (up to 36V) Vcc 1

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� L293D is a typical Motor Driver IC which allows DC motor to drive on

either direction

� L293D is a 16-pin IC which can control a set of two DC motors

simultaneously in any direction.

� L293D IC is a dual H-bridge Motor Driver integrated circuit(IC).

� It works on the concept of H-bridge.

� H-bridge is a circuit which allows the voltage to be flown in either direction.

� As the voltage need to change its direction for being able to rotate the motor

in clockwise or anticlockwise direction, hence H-bridge IC are ideal for

driving a DC motor.

� There are two Enable pins on l293d. Pin 1 and pin 9, for being able to drive

the motor, the pin 1 and 9 need to be high

� There are two Enable pins on l293d. Pin 1 and pin 9, for being able to drive

the motor, the pin 1 and 9 need to be high.

� For driving the motor with left H-bridge you need to enable pin 1 to high.

And for right H-Bridge you need to make the pin 9 to high. If anyone of the

either pin1 or pin9 goes low then the motor in the corresponding section will

suspend working.

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WORKING OF L293D :

� There are 4 input pins for this l293d, pin 2, 7 on the left and pin 15, 10 on

the right.

� Left input pins will regulate the rotation of motor connected across left side

and

Right input for motor on the right hand side.

� The motors are rotated on the basis of the inputs provided across the input

pins

As LOGIC 0 or LOGIC 1.

� For rotating the motor in clockwise direction the input pins has to be

provided with

Logic 1 and Logic 0.

• Pin 2 = Logic 1 and Pin 7 = Logic 0 | Clockwise Direction

• Pin 2 = Logic 0 and Pin 7 = Logic 1 | Anticlockwise Direction

• Pin 2 = Logic 0 and Pin 7 = Logic 0 | Idle [No rotation] [Hi-Impedance state]

• Pin 2 = Logic 1 and Pin 7 = Logic 1 | Idle [No rotation]

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2.3 CIRCUIT DIAGRAM

• POWER SUPPLY

• MAIN CIRCUIT

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2.4 WORKING

Construction and Working Principle:

Connect a 9V batteryto the breadboard with the help of a battery holder. The

positive power supply is passed to the IN of IC 7805 (1), and sent out through the

OUT (3). The negative power supply is sent to the GND(2) connection of IC 7805.

In between, two capacitors (C1 & C2) are connected to the IN and OUT of IC 7805

respectively. As a result of this process, 5V of current is obtained.

Now, connect an IC LM358in the breadboard. As it is a voltage comparator,

it will predict the output from the photodiodes based on the input voltage. For

instance, let us consider that the voltage at 3rd pin is more than or equal to the

voltage at 2nd pin. At this time, the 1st pin of IC LM358 will be high or else it will

stay low. A 10K resistor is coupled with each photodiodes. Then, place an IC

L293Din the breadboard, and join the 2ndand 15th pin of it with 1st pin of IC

LM358. In between this connection, include a LEDwith the 10K resistor.

The four – core wire of left motor is connected to the 3rd& 6th pin of IC

L293D, while the right motor is attached with 11th& 14th pin. The two 10cm

wheels are mounted with the motors. A castor wheelis included at the front of the

robot for balanced and comfortable movements. A power supply of 5Vis applied to

the 1st, 7th, 8th, 9th, & 16th pins. The remaining 4th, 5th, 10th, 12th,& 13th pins are

connected to the ground.After finishing all the circuit connections, place the robot

in the dark room. Connect the 9V battery and power the robot. Now, show the

lightin front of the robot, and it will followthe light wherever it goes.

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CHAPTER 3

PCB FABRICATION

A printed circuit board is defined as an insulating material into

which an electronic circuit has beenprinted or etched.PCB is developed by etching

process. First of all the required circuit is designed and a layout is prepared. The

layout can either be done with hand or by using PCB designing software like

“WINBOARD” or “ORCAD”. Since layout preparation using software is much

less tedious and more flexible,the layouts for circuits was designed using

orchard.The layout of the circuit is transferred to the PCB with proper

interconnections.The layout is made on the PCB on the component side as well as

on the copper clad side.Spaces are provided for drilling holes for inserting the

respective components of the circuit. Now the instrumental interconnections are to

be done.

Printed wiring is of two types:

• Rigid type

• Flexible type

The process begins with copper foil bonded to an insulating

copper clad material.The bonding occurs through an electroplating

operation.Following suitable cleansing and other preparations, a pattern of desired

circuit configuration with interconnections are marked first with a scribbler. Then

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the stencil of the above layout is made on a plastic transparent sheet and is used as

a mask.

Different steps involved in the fabrication of a PCB are as follows:

1. Components layout designing.

2. PCB layout designing.

3. Transferring the PCB layout design onto the PC board laminate.

4. Developing the PCB.

5. Other operations like drilling, cutting, tinning etc.

1. COMPONENTS LAYOUT DESIGNING

Component layout designing is the placement of different components with

their interconnections as per the circuit diagram on PCB board. This exercise

usually begins with an estimate of size of PCB needed to accommodate various

circuit components. Interconnections can be made by drawing lines known as

tracks.

2. PCB LAYOUT DESIGN

PCB layout designing is the mirror image of components layout. The

components layout is drawn looking from the components side whereas the PCB

layout is drawn looking from the copper side. It is obtained by taking a carbon

copy of the computer layout by placing a reverse carbon underneath the paper.

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3. PCB LAYOUT ONTO PCB LAMINATE

First the PCB laminate is chosen. The copper side of the laminate is

thoroughly cleaned with petrol to make it completely free from contaminants. The

PCB layout is drawn on the copper side. Care should be taken to position of the

holes. The same is redrawn giving proper width to different tracks and leaving

proper space using permanent marker.

4. DEVELOPING THE PCB

In this process, all excess copper is removed leaving behind only the drawn

pattern. To do etching, an aqueous solution of ferric chloride is poured into a tray

with the quantity depending upon the size of the PCB to be etched. The mark is

then removed using an alcohol.

5. DRILLING AND TINNING

After etching, drilling is done. The diameter of holes varies from

components to components. It is1mm for IC pins, 1.25 for resistors and capacitors,

1.5mm for diodes and even larger for mounting presence. Tinning can prevent the

oxidation of copper portions which can be done by using a soldering.

3.1 SOLDERING

Solder is an alloy of lead and tin used to fuse metals at relatively low

temperature, about 260-315k. The joint where two metal conductors are to be fused

is heated and then solder is applied so that it can melt and cover the connection.

The reason for soldering is that it makes good bond between the joint metals,

covering the joints completely to prevent oxidation. The coating of solder provides

protection for practically long period of time. The trick in soldering is to heat the

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joints and not the solder. Either a soldering iron or soldering gun can be used, rated

at 25-100W.

In addition to the solder, flux is used to remove any oxide film on the metal

being joined. The flux enables the molten solder to wet the met.

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3.1COMPONENT LAYOUT

POWER SUPPLY

MAIN CIRCUIT

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3.2 PCB LAYOUT

POWER SUPPLY

MAIN CIRCUIT

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CHAPTER 4

CONCLUSION

Light seeking robot is a mobile machine capable of detecting and

following the light source on the travelling path. It is developed without the help of

a microcontroller. It requires fewer number of electronic components and very cost

effective as well.

ADVANCEMENTS :

� An array of LDR’s sensors can be used for improvement of light sensing

That will give a high accuracy of readings.

� We can also design it using micro controller

� If an ultrasonic sensor is added in this robot then it can avoid obstacles

Which are in its path during following light.

APPLICATIONS :

� alarm devices

� This technology can also be used to measure light intensity for

Applications that require greater precision.

� Camera can use this technology to determine the proper exposure

Time; laptops may use in a circuit that varies screen brightness

According to ambient lighting conditions.

� In solar tracking systems.

� Industrial applications

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REFERENCE

1. www.Electronicsbible.com

2. www.Wikipedia.com

3. www.alldatasheets.com

4. www.Electronicscircuits.com

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APPENDIX

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COMPONENT STUDY

MC78XX/LM78XX/MC78XXA

3-Terminal 1A Positive Voltage Regulator

Features • Output Current up to 1A

• Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V

• Thermal Overload Protection

• Short Circuit Protection

• Output Transistor Safe Operating Area Protection

Description The MC78XX/LM78XX/MC78XXA series of three

terminal positive regulators are available in the

TO-220/D-PAK package and with several fixed output

voltages, making them useful in a wide range of

applications. Each type employs internal current limiting,

thermal shut down and safe operating area protection,

making it essentially indestructible. If adequate heat sinking

is provided, they can deliver over 1A output current.

Although designed primarily as fixed voltage regulators,

these devices can be used with external components to

obtain adjustable voltages and currents.

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Absolute Maximum Ratings (Note 11)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

LM158/LM258/LM358 LM2904

LM158A/LM258A/LM358A

Supply Voltage, V+ 32V 26V

Differential Input Voltage 32V 26V

Input Voltage −0.3V to +32V −0.3V to +26V

Power Dissipation (Note 3)

Molded DIP 830 mW 830 mW

Metal Can 550 mW

Small Outline Package (M) 530 mW 530 mW

Micro SMD 435mW

Output Short-Circuit to GND

(One Amplifier) (Note 4)

V+ ≤ 15V and TA = 25°C Continuous Continuous

Input Current (VIN <−0.3V) (Note 5) 50 mA 50 mA

Operating Temperature Range

LM358 0°C to +70°C −40°C to +85°C

LM258 −25°C to +85°C

LM158 −55°C to +125°C

Storage Temperature Range −65°C to +150°C −65°C to +150°C

Lead Temperature, DIP

(Soldering, 10 seconds) 260°C 260°C

Lead Temperature, Metal Can

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(Soldering, 10 seconds) 300°C 300°C

Soldering Information

Dual-In-Line Package

Soldering (10 seconds) 260°C 260°C

Small Outline Package

Vapor Phase (60 seconds) 215°C 215°C

Infrared (15 seconds) 220°C 220°C

See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other methods of soldering surface

mount devices.

ESD Tolerance (Note 12) 250V

__ _____ ___ _____

SLRS008C − SEPTEMBER 1986 − REVISED NOVEMBER 2004

POST OFFICE BOX 655303 � DALLAS, TEXAS 75265 1

_ Featuring Unitrode L293 and L293D

Products Now From Texas Instruments

_ Wide Supply-Voltage Range: 4.5 V to 36 V

_ Separate Input-Logic Supply

_ Internal ESD Protection

_ Thermal Shutdown

_ High-Noise-Immunity Inputs

_ Functionally Similar to SGS L293 and

SGS L293D

_ Output Current 1 A per Channel

(600 mA for L293D)

_ Peak Output Current 2 A per Channel

(1.2 A for L293D)

_ Output Clamp Diodes for Inductive

Transient Suppression (L293D)

Description/ordering information

The L293 and L293D are quadruple high-current

Half-H drivers. The L293 is designed to provide

Bidirectional drive currents of up to 1 A at voltages

From 4.5 V to 36 V. The L293D is designed to

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Provide bidirectional drive currents of up to

600-mA at voltages from 4.5 V to 36 V. Both

devices are designed to drive inductive loads such

as relays, solenoids, dc and bipolar stepping

motors, as well as other high-current/high-voltage

loads in positive-supply applications.

All inputs are TTL compatible. Each output is a

complete totem-pole drive circuit, with a

Darlington transistor sink and a pseudo-

Darlington source. Drivers are enabled in pairs, with drivers 1 and 2 enabled by 1,2EN and drivers 3 and

4

enabled by 3,4EN. When an enable input is high, the associated drivers are enabled, and their outputs

are active

and in phase with their inputs. When the enable input is low, those drivers are disabled, and their outputs

are

off and in the high-impedance state. With the proper data inputs, each pair of drivers forms a full-H (or

bridge)

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reversible drive suitable for solenoid or motor applications.

light seeking robot report

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