A sensor for a control panel, including a housing along an edge of the panel, light emitters projecting light along an in-air detection plane over the panel and detectors detecting reflections of the projected light, reflected by an object in the detection plane, lenses oriented such that each detector receives maximum light intensity when light enters a corresponding lens at a particular angle, whereby for each emitter-detector pair, when the object is located at a specific position in the detection plane, light emitted by the emitter of that pair is reflected by the object back through one of the lenses at the particular angle to the detector of that pair, the specific position being associated with that emitter-detector pair, and a processor configured to determine panel locations, map each location to a position in the detection plane associated with an emitter-detector pair, mapping the panel to the detection plane.