mY JoUrNEy ToWaRdS RoBoTiCs....

Make your Printed Circuit Boards

2009-03-31T11:29:00.000-07:00

Things needed:

Copper board, Ferric chloride(anhydrous), Iron (normal iron used for pressing clothes), Acetone, Photopaper, Printer(Laser printer preferably), Drill(0.8mm dia drill bit)

Software Needed:

Express PCB.

Process:

-Make a simple circuit using Express PCB ( Free software ).

-Print the circuit on a sheet of paper.

-Get the circuit photocopied on the photopaper (gloss side has to be used for printing). This is only necessary if you don’t have a laser printer at home. If you have got a laser printer, just take the printout directly on the photopaper.

-Cut the copper board to the required size. Wash it using acetone.

-Get an iron (normal iron used for pressing clothes). Put the photopaper on the copper board (with the ink side facing the copper side). Now press the hot iron against the photopaper with some force. Do this till the photopaper gets yellow.

-Remove the photopaper slowly from the sides of the copper board when it is hot. The ink should stick onto the board.

-Put ferric chloride in water, till it becomes dark in color. Put the copper board in it and leave it for some time.

-Copper will now be removed from your board. The only place where copper is left is below the laser ink ( toner ). Wash the board using acetone. Remove the ink from the board using acetone.

-You got something which is known as a PCB. Drill holes wherever necessary, Put in the electronic parts and solder them.

Precautions:

- Do not touch ferric chloride solution with bare hands.

- Use a mask while cutting the copper board and during etching.

- Do not put ferric chloride solution in sink after use.

Collage of various robots made by us....

2008-03-08T20:45:00.000-08:00

MADBOT

2007-12-19T06:50:00.000-08:00

This bot was created by Raman and Me. The video explains its working. I should not go into detail.

Controlling Motors using Transistors....

2007-12-02T05:13:00.000-08:00

Atmega16 or any other microcontroller cannot supply enough current needed to run even a 5V motor. Try running a 5V motor using any two pins of your microcontroller ( One pin's output being '1' and the other being at '0' ).
So for this purpose we can use an H-Bridge ( L293D IC ), but if you really want to cut down your cost and make your circuit even simpler, you can go for an NPN transistor ( You may of course use a PNP too ).
The circuit is given below for an NPN transistor. This circuit is very simple to understand if you have little knowledge of transistors. When you give a HIGH to the base, then the transistor's emitter-base junction being forward biased, it starts to conduct. So there is a current flowing through the motor and it runs. Main advantage here is that, base current being very small, can be easily provided by the microcontroller.

BC workshops....

2007-11-06T05:15:00.000-08:00

This is a demo video for the BCWorkshop yearly science and technology club.
BCWorkshops is an year long science and technology club that aims to motivate children to explore and invent.

Controlling your parallel port in a simpler manner..

2007-10-21T06:27:00.000-07:00

Yes this method is quite simpler than making programs in MATLAB or C.

- YOU DON'T HAVE TO BE A PROGRAMMING EXPERT FOR USING THIS.
- IT IS VERY VERY USER FRIENDLY.
- WITH JUST A SIMPLE CLICK OF BUTTONS YOU CAN CONTROL AN EXTERNAL DEVICE USING YOUR COMPUTER.

Download this program from the following link... It is Relais Timer.. And don't be afraid of downloading it. It isn't spam. I downloaded it too, and it works perfectly fine.
http://www.zoekelektronica.nl/software/relaistimer11.exe

Measuring Temperature

2007-10-17T05:14:00.000-07:00

Here is this IC(LM35). You can use this to measure surrounding temperature. It has an output voltage that is proportional to the Celsius temperature.
That is,
(the voltage given by the output pin of this IC) * 100 = Temperature in degree celcius..
The scale factor is .01V/^oC and covers a quite good range of 0 ^oC to +100 ^oC.
Just give +5V to the +Vc pin ( otherwise the range may be 4-30V ) and ground to the middle pin.

R_a = V_c /10^-6Actually, it can range from 80 Kilo ohm to 600 Kilo ohm , but most just use 80 Kilo ohm.
You can connect the output of LM35 to to the ADC of your microcontroller and display it on an LCD.

Or you may use RS232 to get it displayed on your computer.

Introduction to parallel port

2007-10-02T00:07:00.000-07:00

The computer parallel port is the easiest way to control devices outside the PC, like LEDs, lights and even home appliances.
In fact the idea behind parallel port is really simple. It is an 8-bit parallel interface, so you have eight bits available there. Simple put, since each data bit can be set as either “0” (“turned off”) or “1” (“turned on”), we can directly turn on or off up to eight devices, like LEDs, lights and even home appliances. You can connect LEDs direclty to the parallel port and play with them. I did play with them.
And trust me its very interesting and enjoyable to control something with computer.

So, all you need to do is to connect the positive terminal( longer leg) of the LED to any one of the pins (2-9) and the other to any of the pins from 18-25. Pins 18-25 are ground pins and are internally shorted in your computer. Pins 2-9 are data pins and you can give 0V or 3V to them through programming. So when you give a +3V to the pin to which you have connected the LED's longer leg, there is a potential difference created across it and it starts to glow.

Its a common practice to put a resistance (1K) in series with the LED so that it does not burn.
There are many programs to operate your parallel port pins. Just explore the internet for further information.

And yes, you can always use MATLAB and C too.
I will recommend MATLAB for this purpose. So, ALL THE BEST.....

Working Line follower

2007-09-29T07:42:00.000-07:00

This line follower works excellently. We used two sensors and Atmega16, Bascom-AVR for programming the microcontroller.
Not much to say, just play the video and enjoy.

Something about ADC's

2007-09-28T22:43:00.000-07:00

ADC stands for Analog to Digital Converter. Signals in real life are in the form of analog signals. These have to be converted to Digital signals to be understood by the micro controller. Output given by sensor such as LDR, IR, LM35 sensors etc. are given to the ADC.

In Atmega16 the ADC value shown = Vin * 1024 / 5

where Vin = voltage given by the sensor which is ultimately given to the ADC pin
5V = reference voltage (can be changed..)
1024 stands for the 10bit inbuilt ADC in Atmega16

not getting into the details of ADCs, I will end this topic. I hope this helped anyone out there.
For more info just go through the atmega16 datasheet.

Built this for my time pass..LOLZ.

2007-09-05T08:19:00.001-07:00

Now this.... i don't know what to call this.. hehe.
When i was alone at my house, i wanted to do something for my time pass.
So i built this. I just took two DC motors, clips, pulleys, M-seal, rubber bands etc..
Pulleys are not directly connected to the motor shaft. A pen refill is used for this purpose. This idea was given by RAMAN. First we inserted the shaft inside the refill and then joined the pulley with the pen refill using M-seal. This way we were able to save the shaft from any damage. Of course anybody can do it directly. But then i don't think you can use the same motor anywhere else. Yes rubber bands are there to provide gripping. We were not able to find tyres, thats why we used pulleys.

Our sumo BOT

2007-07-13T22:25:00.000-07:00

This sumo bot was started by Akshay,Mayank and Pankaj. I came into the team afterwards. But this one also was a total disaster. When we reached the competetion, the motors were gone.

The bot has been dumped by us and now we no longer know where it is.HEHE

My first BOT.. and YES, it turned out to be a disaster.

2007-07-12T20:36:00.000-07:00

It is a Line follower, but my bot left the line after some time. It was only because of wrong program code. But it was a very good experience overall.

Everything i know is only because of IURS team members and my friend DEBORSHI SAHA.