insted of L293D (works only at 600mA current)
use ULN2003
its a darlington array
for driving stepper motor you need connect the common pin of stepper and 9th pin of 2003 to supply and 8 pinof 2003 to gnd.
dont forget connect the gnd of microcontroller to gnd of 2003
the connect the remaining terminals of stepper motor to pin 16,15,14,13 of 2003 . then the controll pins will be 1,2,3,4 respectively
http://homemaderobo.blogspot.in/2012/03/stepper-motor.html