well, in one of your other dozens of threads (sigh) we talked about behavior along the lines of steering forward until an object is detected and turning left until it isn't. That's pretty primitive behavior. A microcontroller would give you gobs more flexibility -- determine what distance at which to turn... or make the speed of the turn proportional to the distance... randomly turn right or left. Or use two detectors, pointing 45° right and left and turn away from the object, or turn totally around. And that's super simple stuff. You could make it quite a bit more complicated than that yet.
Michael