If you want to try the optical route, you can control the direction by having a stiff bit of wire wrapped 2 turns around the spindle, with a bit sticking out at each end, so it has a kind of slipping clutch action. Then you just have a slotted disk or whatever, your photo-interrupter, and the ends of your bit of stiff wire can press one of two switches so one tells you it's going up, the other one is for down. Sorry it's not a ready made thing, but it's light to turn if you do it right, can be quite compact, and you get the satisfaction of making it! (I saw this arrangement on a volume control on something once, so it's definitely been done before)