Stepper motor for Line Follower

[s.mosfet]

i would make a Line Follower Robot,
with LPC2103 and 2 stepper motor..
but which should i use?
Unipolar or Bipolar? and why?

[JohnS_AZ]

Probably bipolar.

Bipolar gives you greater low speed torque, and it's simpler to drive.

Unipolar usually gives you more steps per rev, and the torque curve is flatter across it's speed range although it's lower than bipolar. It's also a little more complicated to drive.

[Alex]

Unipolar's are easier to drive in terms or components needed.

In any case, please read this (to start)

http://ww1.microchip.com/downloads/en/AppNotes/00907a.pdf

and the answer should become obvious.

It would be great to learn the basics of stepper motors while doing this project.

Here a stepper motor was used to rotate the sensor turret. It is using a PIC18F-something controlled by a PIC32MX-something over I2C. An external driver chip from ST was used.

http://img11.imageshack.us/img11/7018/13052009319i.jpg