Lavet type stepper motors
You'll need to consider how much current the motor takes, and compare it to the microcontroller's datasheet, which will state the maximum current draw on any pin.

Whatever you do, you'll also need to add a flyback diodes. When the MCU or driver attempts to change the current suddenly, the coil will generate back EMF (a possibly large voltage). Since you will be using current in both directions, you'll need 4 diodes. 



My advice though would be to use an H-Bridge chip.