Because you've told us nothing about your device, the only answer can be "the right one"
Here is some information about what I am upto I am making a smart windmill system in which the windmilll is able to adjust itself according to the direction in which wind is blowing in order to make the traditional windmill system more efficient so i have created a wind direction detection mechanism now I want to turn the dome of my windmill according to this detected direction with the help of some motor mechanism so I need help with that...................