i just heard that arduino is more better than other microcontroller.
That's hardly breaking news. We've known that for a while.
can anyone help me how to interface arduino uno rev3 with unipolar stepper motor by using motor shield l298n and controlled by lcd keypad shield.
Sure. How much are you willing to pay?
im new for this programming.
Then why did you take on this assignment?
Having gotten that out of the way, have you any links to the hardware that you have? There are dozens of motor shields based on the L298N chip. Each is subtly different.
Have you got a link to the LCD keypad shield you are using?
Have you got any idea how to connect the stepper motor to the motor shield? Which motor is it?
Finally, what, exactly does "interface arduino uno rev3 with unipolar stepper motor by using motor shield l298n and controlled by lcd keypad shield." mean?
The interface between the motor shield and the Arduino is pretty much defined by the idiot proof arrangement of the pins. That is, it only fits one way.
The interface between the motor shield and the motor is pretty straightforward. What it is, though, is not a programming issue.
The interface between the LCD keypad shield and the Arduino is the same as that for the motor shield. One way that it fits.
So, that leaves control as the remaining issue. What, exactly, do you want to make the motor do when the 3rd switch on the keypad shield is pressed? When it is released? What about the 4th switch?
You need to start with defining your software requirements. Until you do that, there is no programming to be done. And, of course, you need to work out your hardware issues before tackling the software issue.