Methods and devices for calculating the position of a movable device are disclosed. The device may include multiple optical detectors (ODs) and the movable device may include light sources. Optics may be above the ODs. A controller may calculate the position of the light source based on data from the ODs and properties of the optics. The device may be a game console, and the light source may be a game controller. The roles of the OD and light sources may be interchanged. The rotation of the movable device may be determined using multiple light sources and/or multiple ODs on the movable device. The movable device may calculate its position and transmit it to a console. The light sources may be modulated by time or frequency to distinguish between the light sources. There may be two or more movable devices. There may be two or more consoles.