stepper motor + beamsensor

[dsesmg]

Hi. I am trying to build a small conveyor which moves(rotates) for a designated distance whenever a beam sensor is disturbed.
I need my conveyor to carry more than 10kg.
So, I will buy a stepper motor which pulls more than 10kgf after a testing process.
I now have a stepper motor(for testing) which has a specification as below.

    *Voltage      *Current      *Resistance     *Inductance     *Holding torque
        4.0V              0.95A          4.2Ohm           3.3mH            1.6kgf.cm

And, I have a beam sensor which is operated at 12VDC and detects 0~5VDC variable voltages.
So, the stepper motor should be rotated for a designated distance only when this beam sensor is disturbed.
To achieve this, could you teach me what type of IC chip should I use and how to configure the schematic of it for this application?
Please help~!

[dsesmg]

Hi, guys.
Will this schemetic work with WinAvr programer?
http://electronics-diy.com/electronics/stepper_motors.php

This schmetic doesn't include any connection for beam sensor.
Could you advise me how to connect beam sensor to ULN2003?
My beam sesnor has three wires.
Blue - receives signal voltage from controller
Gray - VCC(12VDC)
Black - Gnd

[Admin]

You need to use a microcontroller connected to a stepper motor driver.

Search around and buy what looks good to you. Connecting them up is easy after that.

As for the beam sensor, you use the ADC port of your microcontroller. I recommend just using a Sharp IR range finder.

If you use my Axon microcontroller, its pretty much all plug and play.