This document describes an obstacle avoidance robot designed and built by Elijah Barner. The robot uses an Arduino Uno microcontroller along with an ultrasonic sensor and motor shield to drive two DC motors. The ultrasonic sensor transmits and receives radio frequency signals to determine the distance to obstacles in front of the robot. The Arduino code translates the sensor signals and controls the motors to maneuver around obstacles by moving forward, backward, or changing directions. Diagrams show the hardware components and signal flow. The appendices provide additional illustrations and definitions of the inputs, outputs, software, and references used.

1. OBSTACLE
AVOIDANCE
ROBOT
12/1/2016
ABSTRACT
Self-designed obstacle avoidance robot.
Elijah Barner
ECET 402 Mechatronics W/ Lab

2. Table of Contents
Table of Illustration………………………………………………………. Pg. 2 and 4
Description of Operation…………………………………………………Pg. 6
Hardware Block Diagrams………………………………………………Pg. 7 and 8
Input/output Definitions………………………………………………….Pg. 9, 10, and 12
Theory of Operations…………………………………………………….Pg. 12
Software and Hardware Operations…………………………………..Pg. 13
Hardware, Implementations, and Findings……………………………..Pg.14
Appendances……………………………………………………………….Pg. 15
References…………………………………………………………………..Pg. 16

3. Table of Illustrations
A basic illustration of the hardware that was used:
Appendix A:

4. Appendix B:

5. Appendix C:

6. Description of Operations
This robot was designed and program to work autonomously to avoid and obstacle. For an
example if a wall or table is in front of it the ultrasonic sensor broadcast a signal using
transmitter radio frequency and wait for the signal to bounce to its receiver. Then the code in C
language translate the analog signal from the sensor to the microcontroller. Afterwards the DC
motor rotate clockwise or counter clockwise to go forward, backward, and changes directions.

7. Hardware Block Diagram I.
ARDUINO UNO
ADAFRUIT MOTOR SHEILD
Motor A Motor
B
[Ultrasonic Sensor/
Transmitter and
Receiver

8. Hardware Block Diagram II.

9. Input / Output Definition
A basic diagram for obstacle avoiding robots showing various input/outputs.
Appendix D
Power supply: 5 to 12 VDC

10. Arduino Uno:
Input voltage 5 to 12 VDC
Output voltage 3.3 to 5 VDC
Processor: AT-Mega 328
14 Inputs/Outputs pins
6 PWM and 6 analog inputs
16 MHz crystal oscillator
Supports both SPI and SCI
USB to serial bus connection

11. DC Motors:
2 to 10 VDC
Adafruit Motor Shield:
Four bidirectional support for DC motors.
Four H-bridge (L2930 chips support 0.6A of current.).
Supply voltage 4 to 12 VDC.

12. Theory of Operations
The theoretical aspects of operations depends on several major things how the ultrasonic sensor
interact with the real world. Also that interaction of real-world send an analog signal threw the
sensor to the microcontroller threw a feedback system the robot makes a decision on wither or
not to react to an obstacle in front of it and avoiding.

13. Software and Hardware Operations
Arduino interface using C programming:
Appendix E
Transmission and receiving of the analog signal (RF signal) the robot has to make the decision
to avoid the wall/ obstacle in front of it. Black arrow transmission and Yellow indication of
receiving.

14. Hardware, Implementation, and Findings
The Arduino UNOmicrocontroller was used as the main control module. The Parallax ultrasonic sensor
that is the transmitter and receiver for analog signal via radio frequency. Purchased both a plastic
hardware enclosure to hold all of the hardware and to also work as the chassis. The blue bracket also
purchase fromRadioShack are also for the DC motors mount. Servo motor used was to give the robot the
ability to scan the surrounding area at angle of 180 degrees in of it also to judge the distancesbased on
location of the obstacle.

15. Appendices
Appendix A, B, C ………………………… Table of Illustration
Appendix D……………………………….. Input / Output Definition
Appendix E ……………………………….. Software and Hardware Operations

16. References:
http://www.robotshop.com/en/parallax-ping-ultrasonic-
sensor.html?gclid=Cj0KEQiAsf_BBRDMpoOHw4aSq4QBEiQAPm7DLzlSWpTaBs8U9ZzwghEt
EsEttbbjLXmA9ANDTybU7agaArQS8P8HAQ
http://playground.arduino.cc/Main/UltrasonicSensor
https://www.arduino.cc/en/Main/ArduinoBoardUno
http://playground.arduino.cc/Main/AdafruitMotorShield