Interfacing a DC chopper circuit with Arduino

Question

I am trying to build a stepper motor driver, and I intend to use a DC chopper circuit and a current-sensing resistor to maintain the current through my windings at rated value even at relatively high speed to be able to sustain rated torque. My present challenge is with getting a circuit I can use to chop a DC power source (24 V, 2 A) to sustain a current of about 1.5 A on my motor windings and interfacing that with my Arduino for PWM control (or otherwise). I should add that i am working with a unipolar stepper motor and its rated voltage is 2.4VDC