Line follower

Line follower


Theres nothing much to describe about this robot..The robot follows line using LDRs and LEDs.The sensor is homemade.

You can see in the video that the robot is moving little left and right.i.e. it wobbles to detect line.It is because  the distance between two LDRs is more than the width of the black line so the robot moves left and right to cover the extra distance.This can be overcomed by using PID algorithm and some better sensors.

The logic is quite simple.

1.If both the sensors(LDRs) doesn't detect a line then the robot moves forward.

2.If the left sensor(LDR) detects a line then the robot turns left

3.If the right sensor(LDR) detects a line then the robot turns right.

As LDRs are analog sensors you will have to debug the values and then set the values accordingly for black/white surface.(its such a big pain especially when using LDRs)

I am soon going to post a complete tutorial.

The robot is powered using two battery packs i.e. 9V battery for arduino and all other components and 6V battery for motors.

Chassis made of acrylic


Side view of tamiya tracks.


Arduino uno and a breadboard


Motor driver circuit


This is  the sensor which detects line.I will soon replace it with infrared transmitter and reciever for accurate line following.


Back side of the sensor(my soldering skills are not that good :))


Bottom view of the robot


Completed robot

Embedded video:
See video


Mgcini S's picture

About this Robot

Hello Sir can you please give the code for this fantastic robot ,my email is :

keejay's picture

good day Sir! can i ask for

good day Sir! can i ask for the schematic diagram of this line follower robot? im a mechatronics student and my thesis is soo much related to this one.. your help would be much appreciated.. thanks.. God bless.. :) here's my email

Martin Velickovski's picture

about this robot

Hello kawal can you give the schematic and the code for this cool robot
ps. can this robot be driven without the motor driver with the ic ?
Tnx this is my mail

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