I am Ajinkya Dixit
this is my first robotics project - " THE LINE TRACER ROBOT WITHOUT MICROCONTROLLER "
These robot contains no any kind of microcontrollers , instead it uses only integrated circuit (IC) and some other electronics parts.

There is a great problem with me about microcontroller's, because of my trade (INFORMATION TECHNOLOGY). I have no any knowledge about microcontroller's but , electronics and robotics is my hobby and strength also. So to making these line follower robot i have struggled from last two months. Finally it's made!!!! . I have made these robot without anyones help and lessions about electronics and robotics.

So r u interested in making these robot ??? then see the following steps.



For this project u will need following components :
1. IC - L2963D The motor driver IC .x 1
2. LDR'S (Light Depending Resistors) x 2
3. White LED's x 2
4. Resistors 10 k x 4
Resistors 100 Ohm x 2
5. POT'S 20k x 2
6. Generel PCB'S.
7. 7-Segment displays (i have used 5 displays. It depends on what u want to display.)
8. 9 v Battery x 2
9. 3 or 6 v DC Geared Motors x 2 .
10. Some other miscellineous parts.

Also the main circuit board is my homemade PCB made out of generel purpose pcb.
to make this u will need:
1.A small PCB(Single sided).
2.Laser printer(only laser printer is better) & OHP sheet.
3.FeCl3(Ferrus Cloride) PCB Etching Solution.
4.Cloths iron.

Gathered Parts Together?
See next step....


Picture of SCHEMATIC:

Now Look carefully following circuit Diagram & try out the circuit on bread board first.
if it is working properly go to making its PCB version. the PCB for the project is homemade PCB that is
shown here.
These Line Tracer Robot uses the main part which is the populer IC chip -IC L293D the motor driver IC / H - BRIDGE IC!!!
The schematic shows the pin - to - pin connections of L293D!!!

I have implemented these circuit on the breadboard first for confirmation and after that the final ckt is implemented on PCB.

Although these schematic shows the use of optoisolators , i have used the simple LED's (white) & LDR's as sensors.
You can use photodiodes as an alternative to LDR's but it requires change in it's sensing frequency due to difference between rate of light absorbed by it in day and night. (CNY70 IS VERY BEST OVER ALL OF THESE).

The value of POT depends on u r choice but in between range of sensors frequency.

To making LINE FOLLOWER ROBOTS i have tried lots variety of motors like toy motor, DVD player motor, tape recorder motor,
and so on. But finally i understood that these motors does not work for these robot.
Hence I have used the 12 v DC Geared motors having 150 RPM.
U can use 3 or 6 v DC Geared motors also.

NOTE: The PCB & whole description is now easily available online. Please go thru the link :

Step 3: Main Part - Making the Circuit !!!

Picture of Main Part - Making the Circuit !!!

I have implemented these circuit on the breadboard first for confirmation and after that the final ckt is implemented on PCB.
The PCB is also made by me at home. It's easy to make at home. Also it's drilled by my small but powerfull homemade drill
machine.(See photos.)

If u are beginner to pcb making then don't worry!! u can make the PCB's at home. To making PCB's see articles on (

The drill machine is made by me at home after use of lots of different types of motors.......finally i got the highest  torque motor from scrap!!!!!!

u can see the drill in photos.

Step 4: Making "The Eyes" - Sensors

Picture of Making "The Eyes" - Sensors

Although these schematic shows the use of optoisolators , i have used the simple LED's (white) & LDR's as sensors.
You can use photodiodes as an alternative to LDR's but it requires change in it's sensing frequency due to difference between rate
of light absorbed by it in day and night. ( IR Reflector- CNY70 IS VERY BEST OVER ALL OF THESE).

The very important part in case of sensors is the distance between two sensors. Refer the following photo which shows the positioning and fixing of sensors.

The value of POT depends on u r choice but in between range of sensors frequency. Generelly 20 k works better!!!

Another important thing is the gap between your track and sensors. You have to set it until the LDR senses the light and rotates
 the motor. It also depends on value of your POT used and currently setted ... % resistence of that POT.

Step 5: TRACK

Picture of TRACK

The trsck is the simple black line having turns on white surface. Remember that these robot works on the track of only black color on only white surface and one another important point is the track must have the width less than the distance between two sensors.
(See image)

I have made the track by using the black electrical tape on white paper. Because to sensing the light and therefore rotating the motor
the complete white surface is necessery. So if u have tiles of any color rather than white then u will require to make the path/track
on white surface.

Step 6: FINISHED!!!!

Picture of FINISHED!!!!

To making  LINE FOLLOWER ROBOTS i have tried lots variety of motors like toy motor, DVD player motor, tape recorder motor,
 and so on. But finally i understood that these motors does not work for these robot.
 Hence I have used the 12 v DC Geared motors having 150 RPM.(

As mentioned above that i have no any knowledge about microcontroller , also currently it is not possible for me to use LCD displays.
So instead of it i have used 7-segment display (just for fun.).

To making the body i tried first using 2 old CD's but the size of my PCB is greater than of CD's So instead i used hard sheets
of old packaging boxes.

The caster wheel at the tail of robot is just used for weight balancing.

Use of 9v PP3 batteries is better than using 6v or 4.5v AA type batteries.

My special thanx to my parents for their support for these project and Mr. T.K.Hareendran of EFY for suggestion about sensors
and thanx to my junior friend Pranjal Joshi for his co-operation and interest in learning something about these project from me.

I hope you will like my project and you will try to construct the same......if yes then ALL THE BEST !!!!

pls comment and rate these article.....!!!!!



Guys must See These videos.........

i have uploaded only one video here.(
I have one another video but i cant upload her due to some technical problem so i am giving direct link on youtube here: must see these video also.

This project is selected by popular electronics magazine "Electronics For You (EFY)" for publish in their magazine and they have published this project in their July 2012's issue. If you want to see this article then please see the PDF attached below. U will find the same project with all details and new improved PCB layout.

Thank you!!!!!!!


Tapan147 (author)2017-01-25

Hi I am a student of electronics I am doing this similar project for our 12th boards mini project would you please mail me the scamatic diagram of the circuit board
My email is

NitinS94 (author)2016-12-11

We are also making the similar project. upon connecting the battery, only one LED works. by reversing the battery polarity, the other another LED works. Can you suggest, how should i fix this issue.

ajinkyadixit (author)NitinS942016-12-13

It seems something wrong in your circuit. Which PCB are you using...??? Have you designed your PCB or soldered on perfboard...???

NishanN1 (author)2016-06-10

hi actually my sensor circuit is not working.i m using ldr and 20k preset and white led as a can i resolve this plz suggest any idea.

'manhas' (author)2015-09-18

hey .. can u help me with laser harp?

ajinkyadixit (author)'manhas'2016-04-28

Yes.... I will... Whats is the issue...??

eagleanurag (author)2015-11-09

how the seven segment is dispalying hello

ajinkyadixit (author)eagleanurag2016-04-28

I have set those segments ON which i wanted to GLOW. Remaining are set OFF.

WaqarA14 (author)2015-09-15

Great, It really help my juniors.

Srasi (author)2015-08-04

hii ajinkya.. i am working on this same type of project .... i have question about seven segment, which type of seven segment we have to use? either common anode or common cathode type ?

kv3030 (author)2015-06-12

super bayya

bkay hbo (author)2014-02-26

Hello, i am new about electronics and i have tried to make this robot..i used LED's and LDR's for the sensor.. the problem is my sensor not working very well..i'm not using the POT to the circuit because i can't see your POT in your circuit..where u connect the POT? can u send me the schematic with the POT connection in your circuit? my email:

Pranavthegreat (author)2012-07-21

hey ajinkya i m an indian too and i loved ur project
may i know from where u buy these parts and if u live in mumbai then it is very good for me

Hi Pranav,
Thanx to being my follower and interest in my this project.
I am from kolhapur, which is not so far from Mumbai. I think u know about it.
U can get all this parts from the electronics shops at Lamington road , Airoli , Mumbai. I got it from electronics hobby shops in my city. May i know your surname???
If you are on facebook then connect with me on it. Also if you are reader of EFY magazine , then see this month's (July 2012) issue. U will get my this project in it too.

my surname is jain but i not a jain an too buy parts from lamingtan road but from which shop i ll get parts for making a custom pcb and my username is Pranav r jain on fb and never heard of EFY magazine plz check my projects too

okk...... i will tell u shops. Although i am from kolhapur , i know such shops in mumbai too...!!!

GALA Electronics.
20,Kalpana Building,1st floor,357,Lamington Road,opp police station,
mumbai ,400 007. Contact: 23863549 , 23823552

NEX Robotics Pvt Ltd.
Office No. 1,
Ridhhi - Sidhhi Heights, Plot No. 59,
Near Euro School, Sector 19,
Airoli, Navi Mumbai 400 708,
Maharashtra, INDIA

nwalawalkar (author)ajinkyadixit2014-02-12

Hi Ajinkya,

Found your project very good. I am a software professional, work on .Net. I am completely new to electronics and started my hands with Arduino. Found your instructables while looking for line robot. Just to let you know, as a matter of fact, while looking for parts I have been to both the places you have mentioned above. Nex is close to my house and Gala I have just been yesterday to buy a HC-05, which I got from Mac-Net their child company ;-)

Nitin Walawalkar

Madhuriruparel (author)2013-09-02

My project is to create a mobile robot that reaches destination and if any obstacle come s in between it will avoid it,for that it compares image pixel by pixel
Does i require Micro controller for this project?
Please do reply

Your idea is really awesome. If you are going to compare image pixel by pixel, of course you will need to use image processing. So you must need a microcontroller. If you don't want image processing, then you can use the above circuit with only replacing of line sensor to obstacle sensor and few other changes.

al 01 (author)2013-07-27

at my city there is no one selling 74LS04,what should i use?

ajinkyadixit (author)al 012013-07-28

The 74LS04 is not gate and it is needed only if u want to make it capable of following white line. If u dont want white line follower, then u can omit that IC. Else no alternate to that IC.

endrytama (author)2013-05-20

can i replace the DC motor with Servo motor ?
if yes will the layout and component different from the list u mention above..

Thanks in advance

ajinkyadixit (author)2013-04-13

I have sent you the mail. Also visit my blog for other ideas.

zankar (author)2013-04-12

"be nice"
I am working on line follower but i have no detail about this project so please can you send me full circuit diagram and programming of line follower o

hmnt.sngh (author)2013-01-21


apoorveinstein (author)2012-08-21

Nice 'ible...
Tx for sharing...
Your project is printed in the July 2012 issue of EFY where you had used the TCRT5000L sensor, is it worth using it(sensor) or I can get the same results by using normal white LED and LDR????

And what 'bout the IC 7805????

Plz upload the pcb files....

@ apoorva visit my blog :


Download the the first attachment from the post.

U will get an EFY article in which my PCB layout is published.

The problem in uploading pcb files is, i am using the "circuit wizard" for making the pcb's....... so this s/w is not used everywhere........

If u have circuit wizard then i will upload ....... sure...... But before get a look on my blog an the attached EFY article.

Thank You....!!!!

Waiting for reply / queries....

Thanx apoorveinstein....... As you seen my article seen in EFY.

Actually i have used the simple LDR and LED's in my robot. But this website is standard and international website. So i just mentioned the TCRT5000L in robot.
U can use CNY70 too. I have used it also. There is no difference between TCRT and CNY70. U can also get the better result with the use of LDR and LED.

Now about 7805. It is the voltage regulator to provide only 5V by taking up to 12V as input voltage. Generally any IC needs up to 5V for operating. The L293D can work on 12V too. But it heats too much and also as the motor supply voltage is 12V,the battery gets discharged very fast. So i have used it to provide 5V for IC's.

Prefer the circuit published in EFY. That circuit is improved and is of both white and black line follower.

boomg46 (author)2012-07-01

Dear Ajinkya,
may i know the cost of this robot? it will be pleasure to know. Thank you.

ajinkyadixit (author)boomg462012-07-01

Dear Boomg,
This is my first robotic project, so i used all new parts like motors. So i spent $10 (500 INR). If u want to make it from scratch i.e. if u already have its specific parts , then u will have to spent less than $5(less than 25INR)

Thank you

boomg46 (author)ajinkyadixit2012-07-03

i really interested to making this robot because it not using the microcontroller. otherwise, the cost is so cheap. but, i want to know, how to use the optoisolator. and that device is so hard to find.

thank you

ajinkyadixit (author)boomg462012-08-22

The opto isolator is easily available. Use CNY70 which is one of the market available optoisolators. See the New schematic and PDF given here in next steps.

Thank You

altaf hussain (author)2012-08-16

i mean if we use CNY70 what will be its connections


waiting for your reply.
by the way i like your project

altaf hussain (author)2012-08-16

can you plz send me the final schematic

i mean schematic whickh uses the ldr and led or cny70 as sensors

my email is

Pranavthegreat (author)2012-07-30

thnxx for ur help if i hav any problem i send u message but my exams are going to start so i ll be busy

Pranavthegreat (author)2012-07-27

what should i call that plastic thing ??? and can i get ferric powder in gala or visha stores???

The name of that plastic sheet is acrylic sheet...... u can find it at any shops where the vehicle number plates are made. And u can get the ferric powder at gala.

Pranavthegreat (author)2012-07-26

see on ur site u demonstrate ur drill by making a hole in plastic sheet so from where can i get that sheet and how to use that ferric powder ??? because most pcb projects are using the liquid one

no matter..... u can get it any stationery too....... now about use of ferric powder, U have to add the some amount of powder into water by the 1:1 ratio...... more powder will work....... wear gloves during this(first time only..... once u imagine then gloves are not necessery)....... if u want to use solution then u can.

Pranavthegreat (author)2012-07-25

And also in ur mini drill u used a plastic sheet from where u hav bought that from

Which plastic sheet dude????

Pranavthegreat (author)2012-07-25

hey i also buy parts from the opposite shop visha electronics and from vega robotics but from where i can get the copper pcb and other parts for making the custom pcb and i prefer u should use for making pcb

U can get Copper clad board and Ferric Powder(NOT THE SOLUTION) for etching PCB's from vega robotics. And i am using the "Circuit Wizard " for making the PCB's

manishkr.iitg (author)2012-06-24

Dear Ajinkya,

You have mentioned two LDRs and two LEDs as sensors. But in ckt diagram, you have shown a photo transistor. More over you have named it as ITR20001/T, which consists of an infrared emitting diode and an NPN silicon phototransistor assembly. Could you please explain that?

yes u are right.... i know that i have shown Optoisolator here. In such application the optoisolator works best than reguler LDR or photo transistor/IR receiever. But this optoisolator is not available everywhere in India and is not so cheap. It's unavailable in my city also. So i used LDR's and after that i have replaced LDR and LED's with another optoisolator named "CNY-70" which is superb over LDR's.


Any way thanx for interest in this my robot. waiting for reply/query. U are always welcome....!!!! :) :)

ajinkyadixit (author)2012-02-23

thanx rahulbiradar............
pls tell me actually what do u want ???

i will upload the report after that........ :)

rahulbiradar (author)2012-02-22

please attach the report file an working discription of each circuit and ic .....good project.....!!!!!!!!

meshgheru (author)2012-02-11

Ok. I download the schematic but on your PCB I observe 2 trimpot which doesnt appear in schematic.

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