"DIY - THE EXCELLENT LINE TRACER ROBOT WITHOUT MICROCONTROLLER"

Hi
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.

Step 1: COMPONENTS U WILL NEED:

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?
Ready?
ok.......
See next step....

Step 2: 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 :http://electronicsforu.com/diy/hardware-diy/simple-line-following-robot

Step 3: 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 (https://www.instructables.com).

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

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

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!!!!

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.(http://www.solarbotics.com)

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.....!!!!!


THANK YOU!!!

Step 7: LET'S SEE THESE VIDEOS:

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

i have uploaded only one video here.(http://www.youtube.com/watch?v=06UsJOJoMG0&feature=share)
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.

http://www.youtube.com/watch?v=gewYLc_qYbw&feature=share

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!!!!!!!