You don't want to power motors and logic circuits from the same supply, its costly to keep replacing blown processors.
If the controller can't provide enough current for the motors then you'll find its costly to keep replacing blown motor driver chips.
A high current bipolar stepper motor really wants a current-limiting chopper drive chip like the A4988, L6208 (many others are available).
Anyway we need to know the specs of the motor and your power supply before commenting further.