Empty as a target for a driver (instead of a mesh)?

I know how to use one mesh as a target to control a driver for another mesh ( or other object). But I can’t seem to select and empty as a target. Can an empty be used? If so, how do you select it? (The eyedropper doesn’t seem to work).

Can an empty be used?
Yes. Select the empty as the control object in the drivers section of the graph editor

Thanks, yes I had found that out after several tries.

Another question: Is it possible to have the drivers update every nth frame, instead of every frame of the animation? For example, have a value change every 10th frame, but then stay constant until the next 10th frame?

Figured it out. Just modify the keyframes in the dope sheet of the target object and modify the F-curve to constant .