This document describes the design and implementation of an obstacle avoiding robot. It includes sections on the required components of the robot such as a microcontroller, Bluetooth module, motor driver, sensors, wheels, and power supply. The microcontroller is programmed to receive Bluetooth commands from a smartphone and control the motor driver and wheels to navigate around obstacles. Circuit diagrams and screenshots of an Android application for controlling the robot are provided. The robot was designed and built by three electrical engineering students for their undergraduate project.

1. DESIGN AND IMPLEMENTATION OF
AN OBSTACLE AVOIDING ROBOT
A project report submitted for the partial fulfillment of the requirement for
the degree of Bachelor of Science (B.Sc.) in Electrical & Electronic
Engineering by:
MD. JOBAER ID: EEEE 120200203
MD. MURSHIDUZZAMAN ID: EEEE 120200183
SAJIB SARKER ID: EEEE 120200181
Under the supervision of
ASM Shamsul Arefin
Assistant Professor
June 2015
Department of Electrical & Electronic Engineering
Faculty of Science and Engineering
Northern University Bangladesh
i

2. DECLARATION
We, hereby, declare that the work presented in this project is the
outcome of the research work performed by us under the supervision of
ASM Shamsul Arefin, Assistant Professor of the Department of Electrical
And Electronic Engineering Northern University Bangladesh. We also
declare that no part of this project report has been submitted elsewhere for
the award of any degree.
Signature
…………………………..
Md. Jobaer
ID: EEEE 120200203
Dept. of EEE
…………………………..
Md. Murshiduzzaman
ID: EEEE 120200183
Dept. of EEE
…………………………..
Sajib Sarker
ID: EEEE 120200181
Dept. of EEE
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3. iii
APPROVAL
This project report “Design and implementation of an obstacle
avoiding robot” completed by Md. Jobaer, ID: EEEE 120200203, Md.
Murshiduzzaman, ID: EEEE 120200183, Sajib Sarker, ID: EEEE
120200181, Department of Electrical And Electronic Engineering, Northern
University Bangladesh has been accepted as satisfactory for the partial
fulfillment of the requirements of the degree of Bachelor of Science (B.Sc)
in Electrical And Electronic Engineering of the year of 2015 and approved
as to its style and contents. The presentation was held on May 31, 2015.
Board of Examiners
………………………
(Supervisor)
ASM Shamsul Arefin
Assistant Professor
Dept. of EEE
…………………
Ashraful Arefin
Assistant Professor
Dept. of EEE
…………………
Saber Nazim
Lecturer
Dept. of EEE
………………………………………..
Engr. Md. Badiuzzaman
Associate Professor & Head
Dept. of EEE

4. iv
ABSTRACT
The objective of this project is to control a robot by using smart phone
& microcontroller to avoid the obstacle. A microcontroller would take input
from the smart phone via Bluetooth and then compare the input to the
L293D motor driver, which would in turn direct the motors to control the
movement of the robot.

5. v
ACKNOWLEDGEMENT
All Praise to Almighty Allah, Who has given us strength and
opportunity to complete the project. We would like to thank our Supervisor
ASM Shamsul Arefin for giving us time and his proper guidance and
valuable advice. He was always with us whenever we faced difficulties. His
comment and guidance helped us a lot to prepare our project report.
After that we are really thankful to all of our teachers for their
help to make this project successfully.
We are also thankful to our classmates and friends who supplied
a lot of information to make this accomplished.
Finally, we are grateful to our family, who are always with us in
every steps of our life.

6. vi
ACRONYMS AND ABBREVIATIONS
µC/MCU MicroprocessorControlUnit
AC/DC Alternating Current/Direct Current
APH Adaptive Frequency Hopping Feature
AVR Automatic Voltage Regulator
CMOS Complementary Metal Oxide Semiconductor
DC Direct Current
EDR Enhanced Data Rate
EEPROM Electrically Erasable Programmable Read
Only Memory
GND Ground
GPIOR General PurposeI/O Registers
IC Integrated Circuit
IRED Infrared-Emitting Diode
LED Light Emitting Diode
Mbps Megabyte Per Second
MHz Mega Hertz
MIPS Million Instructions Per Second
PCB Printed Board Circuit
PIO Parallel Input Output
PWM Pulse Width Modulation
RC Resistor Capacitor

7. vii
RF Radio Frequency
RX > IR Emit Infrared
SPP Serial Port Protocol
SRAM Static Random Access Memory
TX/Rx Transmitter/ Receiver
UART Universal Asynchronous Receiver
Transmitter
USART Universal Synchronous Asynchronous
Receiver Transmitter
VDD Drain Voltage
VSS Source Voltage

8. viii
TABLE OF CONTENTS
Declaration ii
Approval iii
Abstract iv
Acknowledgement v
Acronyms and Abbreviations vi
Table of Contents viii
List of Figures xii
CHAPTER – 1
INTRODUCTION
1.1 Introduction to Robotics 2
1.2 Problem Statement 2
1.3 Objective of this project 2
1.4 Report Outline 2
CHAPTER – 2
DESIGN OF THE ROBOT
2.1 Introduction 4
2.2 Block Diagram of the Project 4
2.3 Required Components 4
2.4 7805Volage Regulator IC 5
2.5 HC-05 Bluetooth 6
2.5.1 Overview 7

9. ix
2.5.2 Specifications 7
2.5.3 Pin out configuration of Bluetooth and microcontroller 8
2.5.4 Bluetooth Wireless Navigation 8
2.6 L293D Motor Driver IC 9
2.6.1 Pin Diagram of L293D motor driver IC 9
2.6.2 Working of L293D 10
2.6.3 L293D Logic Table 10
2.6.4 Circuit Diagram of L293D motor driver IC controller 10
2.6.5 Voltage Specification 11
2.7 Capacitor 11
2.7.1 Types of Capacitor 12
2.7.2 Capacitor Voltage Reference 13
2.7.3 104j Capacitor 13
2.7.4 Specification of 104j Capacitor 13
2.8 Crystal oscillator 14
2.9 Heat sink 14
2.10 Resistor 15
2.11 Mini DC Gear Motor and wheel 15
2.11.1 Specification of Dc Motor 16
2.12 LED 17
2.13 Diode 18
2.13.1Characteristic of Diode 18
2.14 Battery 19
2.14.1Application 20

10. x
2.15 Summary 20
CHAPTER – 3
DESIGN AND IMPLEMENTATION
3.1 Introduction 22
3.2 Microcontroller 22
3.2.1 The pin diagram of Atmega8 microcontroller 22
3.2.2 ATmega8 Microcontroller IC 22
3.2.3 Features 23
3.3 Microcontroller Program 24
3.4 PCB Layout 30
3.5 Circuit Module 31
3.6 Circuit Construction 31
3.7 Android application Development 32
3.7.1 What is MIT App inventor? 32
3.7.2 Android application view 32
3.7.3 Screenshot of the Development of Android application 33
3.8 Working procedure 35
3.9 Software’s Used 35
3.9.1Proteus 8 35
3.9.2 Codevision AVR 35
3.10 Summary 36

11. xi
CHAPTER-4
PROJECT OUTLOOK, APPLICATION AND
LIMITATIONS
4.1 Introduction 38
4.2 Project Outlook 38
4.3 Application of this project 38
4.4 Limitation 39
4.5 Summary 39
CHAPTER-5
PRICE COMPARISON AND DISCUSSION
5.1 Introduction 41
5.2 Price 41
5.3 Discussion 41
5.4 Advantages 41
5.5 Disadvantages 41
5.6 Summary 42
CHAPTER-6
FUTURE EXTENSIONS AND CONCLUSION
6.1 Future Extensions 44
6.2 Conclusion 44
References 45

12. xii
LIST OF FIGURES
Figure 2.1: Block Diagram of the project…………….….......................4
Figure 2.2:Typical Voltage Regulator IC …………………..................5
Figure 2.3:Circuitry of Voltage Regulator IC …………………….…...6
Figure 2.4:HC-05 Bluetooth …………………………………….…….6
Figure 2.5:pin out configuration microcontroller and Bluetooth ...…...8
Figure 2.6:16 Pin Diagram of L293D …………………………...........9
Figure 2.7:Circuit Diagram of L293D………......................................10
Figure 2.8:Physical View of Capacitor ………………………………11
Figure 2.9:104j Capacitor ………….……………………………….. 13
Figure 2.10:Crystal oscillator ………………………………………..14
Figure 2.11:Heat sink ..........................................................................15
Figure 2.12:Physical view of Resistor ………….……………………15
Figure 2.13:Mini Dc motor and wheel, stearing wheel ……………...16
Figure 2.14:LED ……………………………………………………….……..18
Figure 2.15: Diode.................................................................................18
Figure 2.16: Characteristics of Diode....................................................19
Figure 2.17:Battery …………………………………………………..19
Figure 3.1:Pin diagram of ATmega8…..…..………………………....22
Figure 3.2:PCB Diagram of this project ………….….……………... 30
Figure 3.3:Circuit module….................................................................31

13. xiii
Figure 3.4: Android application view…………………………….…...32
Figure 3.5.1 Screenshotofthe Development of Android application…33
Figure 3.5.2:Screenshotof the Development of Android application...34
Figure 4.1: Outer look of the robot…………………………………….38