A luminaire controller connectable to a driver circuit of a luminaire, the luminaire controller comprising: a mains power connection; a central processing module; and an isolated supply connected to the mains power connection and via a data transfer line to the central processing module, the isolated supply being operable for providing dimming signals to the driver circuit of the luminaire; characterized in that the isolated supply comprises both a digital addressable lighting interface and an analogue interface, and in that the central processing module is operable to configure one of the interfaces for supplying the dimming signals to the driver circuit of the luminaire in accordance with the mode of operation of the luminaire.