Light Emitting Diodes (LEDs) are increasingly used in illumination applications. To control multiple Light Emitting Diodes (LEDs), or any other controllable light source, this document introduces a single-wire multiple-LED power and control system. Specifically, individually controlled LED units are arranged in a series configuration that is driven by a control unit located at the head of the series. Each of the individually controlled LED units may comprise more than one LED that is also individually controllable. The head-end control unit provides both electrical power and control signals down a single wire to drive all of the LED units in the series in a manner that allows each LED unit to be controlled individually or in assigned groups.