Pin? I am sorry but I think you misunderstand what it does. You dont connect MCU's to your computer and have Roborealm run any kind of module through it. RoboRealm can take the place of the MCU, it runs the image processing. If you are referring to a Motor Driver, you need one that is supported, for instance, all of Dimension Engineering's Sabertooth drivers are. And from there simply go to Control->Sabertooth-> and just slide around.