Abstract: An electronic device which optically determines the relative position of a joystick using one or more sets of light emitters and light detectors. This device simulates the closing and opening of electromechanical switches without any physical contact with the joystick control shaft. Light beams are selectively blocked or allowed to shine on the opposing photo-detector of a set by movement of the joystick. When the photo-detector receives sufficient light a logic high is lowered to a logic low allowing more current to flow through it, thus simulating the closure of a mechanical switch. From the "open" or "closed" states of the photo-detectors, the displacement of the control shaft may be determined. The sensitivity may be easily changed, or the controller changed between a 4-way and 8-way controller by altering the outer diameter of the control shaft, such as by an interchangeable bushing.