1. Engineering Design Project
Department of Computer Science and Engineering
University of Moratuwa
Group Name:- Phoenix
• Gunasinghe U. L. D. N 100162X
• Sashika W. A. D 100487X
• Siriwardena M.P 100512X
• Udara Y.B.N 100544V
• Wijayarathna D.G.C.D 100596F

2. A machine which is built to follow
a specific path is defined as a Line
Follower. The line may have different
appearances
 A Black line on a white surface or
vice-versa.
 An Invisible line as a magnetic
field.

3. • Basic knowledge about electronic
components.
• Basic knowledge on electronic circuit
designing and making.
• Basic knowledge on C Programing.
• Innovative brain and perseverance.

4. As we analyze the problem we
realize that we have to get seven
inputs and four outputs. So we
decided that the most suitable
microcontroller for our requirements
is the 16F877A microcontroller.
It consists of four input/output
ports and PWM module. This
persuades us to use it in our circuit.

6. We have used seven IR sensors and below
you can see the arrangement of those sensors.
1
6 4 2 3 5 7

7.  Sensors 1,2 and 3 are used to detect the
road.
 Sensors 4 and 5 are used to recognize
the mark given to indicate the side which
the robot should turn at the four-way
junction.
 Sensors 6 and 7 are used to recognize
the four-way junction.

9. The IR LED emits a beam of IR and the
surface below reflect the beam. When the
sensors senses the beam it generates a
voltage. This voltage depends on the
amount of the light sense by the sensor.
When the intensity is higher the generated
voltage is higher and when the intensity is
lower the generated voltage is lower.

10. We used three circuit panels to
complete the robot.
 Analog to Digital Converter
 PIC Simulation Circuit
 Motor Interface and Control Circuit

11. Analog output given by the sensors is converted to
digital by the above circuit .

13. This part of circuit can be considered
as the mother board of our robot.
The circuit gets all the outputs of
sensors as the inputs of the PIC. Then the
PIC gives us required outputs.
According to the design of this circuit
we can also program the PIC while it is
attached to the circuit.

14. This part of circuit controls the motors according to the outputs
given by the PIC.

15.  We used PIC C language to program
the IC. We used PIC C because it is
familiar to us and similar to C language.
 We have written the program as
getting inputs from the sensors and
rotating the motors forward and backward
according to our requirements.

16.  In this project we didn’t use PWM(Pulse With
Module) Method. Because we didn’t have
enough knowledge about using it. If we used it
we could improve the performances.
Although we use a 6V power pack with a lengthy
wire, we could make the robot more portable if
we used a rechargeable battery.

17.  Discussion with Mr. Aruna Upul (Department of
Electronics and Tele communication.)
We used following links to get an idea about the
path following robot.
• http://robotika.yweb.sk/skola/AVR/visionrobo%20com/Line%20Follower%20tutorial%20v1.1.pdf
• http://www.botskool.com/tutorials/electronics/8051/line-follower
• http://www.kmitl.ac.th/~kswichit/ROBOT/Follower.pdf
• http://www.docstoc.com/docs/64977263/Line-following-robot-tutorial
• http://www.richardvannoy.info/building-a-line-following-robot.pdf
• http://www.tombot.net/beam/linefollowingcircuit.html
• http://www.ermicro.com/blog/?p=1097
• http://docs.google.com/viewer?a=v&q=cache:WXamZCglK3UJ:vjtirobotics.files.wordpress.com/2008/0
9/linefollower_tricks.doc+build+line+follower&hl=en&gl=lk&pid=bl&srcid=ADGEEShm4TXBoqBpvNTwSc
bQKoI_Wayxn0HBz_QMKTbHpnaf8pVJAK2wPJUIjkFJdz2No0UjmtN8BWTi1BOmqTi0a-
QGbgootbW42Px3xw2nz6dY-j_oFezBrJojYMM-
QFs84oBD5kjz&sig=AHIEtbS8vwB7pLdTJEJoU0PeJOoDoLeBmA&pli=1
• http://www.youtube.com/watch?v=I_NU2ruzyc4
• http://www.youtube.com/watch?v=BLfXXRfRIzY
• http://www.youtube.com/watch?v=6QznAAwL8rI