Introduction: Home Made Line Tracer Robot

About: Electronics is my passion...!!!

In this instructables I will show you how to make a line tracer robot without using any kind of microcontroller.
It is basically works on the property of reflection of light is greater from whiter surface than black surface. Hence when the robot sensors on the black path it receives less light than desired quantity of light and hence the motor stops rotating.

Step 1: COMPONENTS

STEP 2 components
To make this robot you will need the following components:
1.LM358 op-amp chip
2. 220 ohm resistors  x  4
3. 1k resistor    x  2
4. BC547B transistor (NPN)  x  2
5. white LED    x  2 
6. red LED   x  2 
7. 3 or 6V DC geared motors  x  2 
8. copper clad circuit board or protoboard
9. 100k pot   x  2 
10.5k pot   x  2 
11. photo-diode   x  2 
& now you are ready to make ur project…  

Step 2: Circuit Diagram

Place the components in circuit as shown in diagram
(NOTE: HERE PHOTO TRANSISTOR ARE USED IN DIAGRAM BECAUSE PHOTODIODE IS NOT AVAILABLE IN SOFTWEAR. BUT U SHOULD HAVE TO CONNECT ANODE OF PHOTODIODE TO GND OF BATTERY AND CATHODE TO +VE OF BATTERY  i.e diode is in reversed bias.
I suggest you 1st test the circuit on breadboard. Try to solve all problems about connection and then finally place it on PCB or solder…….

watch following link for clear and enlarged circuit diagram:
https://www.instructables.com/files/orig/FKQ/FET5/GXSSLLIM/FKQFET5GXSSLLIM.png

Step 3: Making the PCB

Making the pcb as I shown in fig.
U can also use your own design or u can directly use the protoboard.

for more details and READY MADE PCB DESIGN CLICK: https://www.instructables.com/files/orig/FTJ/QTLQ/GZXW8JKS/FTJQTLQGZXW8JKS.png

Step 4: Drilling the PCB

I drilled this PCB with my friend Ajinkya Dixit’s home made drill machine.

Step 5: SENSORS: the Eyes..

sensors are most important part of LINE TRACER..
here i used IR LED as transmitter and PHOTODIODE as receiver. u can also use bright red or white led but IR led increases the accuracy of sensor unit..

for details and READY MADE SENSOR BOARD DESIGN CLICK:https://www.instructables.com/files/orig/FIM/ZXX5/GZYCFV1I/FIMZXX5GZYCFV1I.png

Step 6: Making the Track

U can use any black strip for making the  track for your robot. But remember that there should some free white space near your track . if there is no white space then your robot will not work…
Also don’t turn your track in acute angle because response output timing of LM358 is good but as the sensor sense due to the turn the RPM and speed of motor the robot leave  the line..

Step 7: Testing

U can use any black strip for making the  track for your robot. But remember that there should some free white space near your track . if there is no white space then your robot will not work…
Also don’t turn your track in acute angle because response output timing of LM358 is good but as the sensor sense due to the turn the RPM and speed of motor the robot leave  the line..

Step 8: Some More Snaps...!!

Step 9: Updates..!!

you can also make the white line follower from the same given circuit.. :) :)
just u need to change inputs between
1) pin2 and pin 3
2) pin5 and pin 6
and u r done..

there is also change in body of robot. so watch its new cooool look..!! ;)

Step 10: Video..!!

watch the following video for better understanding of line follower robot technology.. :) :) here you go. and all the best for your BoT.. :)

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Toy Challenge 2

Participated in the
Toy Challenge 2