I made the circuit according to the circuit given in this link :http://www.betasix.net/connecting-a-unipolar-stepper-to-arduino/
But the motor didn't work at all
Some help please....
The "fritzing" diagram shows the motor running from the Arduino +5.
[Maybe it's just me, but, I question running that motor from Arduino +5.]
And that author's photo shows only the Arduino digital wires going to the breadboard - and that will not work like that.
Better take a picture of your set-up, one where all the wiring can be analysed.
Exactly what motor do you have - that site is assuming a unipolar stepper motor (5 6 or 8 wire) with high-impedance windings
(20 ohms or thereabouts).
This is our circuit that we made in the attachment.This time around the chip was burnt out.We are using a 6-wire unipolar stepper motor.
I noted (see Reply #1) that it looks as like there is no connection between Arduino Gnd and the motor circuit in the link you supplied.
And it looks like there isn't one in the picture that you attached.
The battery's negative terminal goes to the IC's pin 9, good, but it must also be connected to Arduino Gnd.
The battery's negative terminal goes to the IC's pin 8 and 9th pin is COM port which we give +12V
Actually the fritzing diagram shows the motor running from Vin, not 5V.
The photo is of a different configuration where the motor is separately powered - the missing ground
wire is wrong, but the circuit may well happen to work anyway since the Arduino outputs will always have
some LOW and some HIGH. Its a good example of a bad circuit that happens to work by accident.
Well the motor is working now but the chip repeatedly burns out.So,I measured the current flowing in the circuit which was 12A which is very high and i think that's the reason why the chip burnt out.So i was hoping that we can control the current through MOSFET transistor.Can you please guide me how i can use it ?
I repeat my question:
Insert Quote
Exactly what motor do you have - that site is assuming a unipolar stepper motor (5 6 or 8 wire) with high-impedance windings
(20 ohms or thereabouts).
I gotta get a better monitor... 
I have a unipolar stepper motor(6 wire) with resistance 8.3 ohms.Other specs can be found at this site:http://www.evselectro.com/motors-stepper-motor-17pm-j-thailand-2541
I now tried with an 13005a mosfet. It is now not burning up but the motor is not spinning either.When I try to spin the motor by hand, it offers some resistance too when you connect it to battery. I am getting really confused.Could someone please help???It would be of great help...