[IKE]

If it only sweeps between 2 positions, then 2 limit switches may work well. Make sure you use something other than the limit switch as the physical stop, apply the limit switch in a way that it has a little compliance. Often this can be accomplished by bending the limit switch tab into a shape that can flex.

If you need to stop at various angles, I would recommend a potentiometer. Be careful when installing as it is really easy to turn too far, and break them.