i.LIGHT: Communication Using Visible Light
Communication among mechatronic devices can be achieved in many ways. The use of visible light is one option, which has several advantages. i.LIGHT is a technology using visible light from light-emitting diodes (LEDs) as a medium to transmit information in open space. It was originally developed with an aim to use LEDs for illumination and broadcasting of information concurrently. Through prototypes development it has been shown that visible light can indeed be used as a medium for short-range, wireless communication. Essentially, all LED light sources can become information sources or beacons, in addition to the usual function utilized in visual illumination or display. Both digital and audio information can be transmitted using visible light. In this chapter, an i.LIGHT prototype design, an EXIT sign to broadcast audio information for providing guidance to visually impaired people and others is discussed. The i.LIGHT technology has also been extended to the use of digital cameras as receivers.