This invention comprises a control interface between a machine and a physical object. The invention includes an infrared transmitter for transmitting a first infrared signal to an object. Upon striking the object, the infrared signal is reflected forming a reflected infrared signal. An infrared receiver receives the reflected signal from the object and the reflected signal is transformed into a second signal which may be either an analogue type or a yes/no threshold type, representative of a distance between the object and the receiver. The second signal is coupled to the machine. The apparatus is a cordless touch-free controller interface for use with a machine. The present invention is ideally suited for controlling cursor position for use with computers and also with video games.