The precision of motion of a stepper motor is several magnitudes higher than a simple DC motor. For a project that needs weeks to execute I wouldn't save the few bucks for a micro.
> precision of motion of a stepper motor is several magnitudes higher than a simple DC motor
Depends on whether we're talking about open-loop control or closed-loop control. A stepper motor can only move in half-jumps or full-jumps. The size of the jump is intrinsic to the motor, and can be reduced with a gearbox. If we're doing closed-loop control of a DC motor, the resolution is limited by the feedback encoder, which typically has a resolution a magnitude or two higher than a stepper motor's.
Depends on whether we're talking about open-loop control or closed-loop control. A stepper motor can only move in half-jumps or full-jumps. The size of the jump is intrinsic to the motor, and can be reduced with a gearbox. If we're doing closed-loop control of a DC motor, the resolution is limited by the feedback encoder, which typically has a resolution a magnitude or two higher than a stepper motor's.