In a conventional lighting system, a light source can be merely switched on/off manually, while, instead in a smart one, various preset lighting modes are preloaded into the lighting system, either wired or wireless, to meet the user’s specific needs. Besides, conventionally, a heavily loaded lighting system necessitates a high-capacity switch, and requires a large volume of cables to drive a distant load. In contrast, a load is directly powered by an output driver, meaning that there is no need to increase the power capacity of a switch when the system is heavily loaded, and it merely requires a long signal line to drive a distant load. Furthermore, a smart lighting system can be made dimmable and controllable by timer means.

As illustrated in Figure 1, a smart LED lighting system comprises a rectifier followed by a power factor corrector and then by a DC/DC converter [1].Figure 1.Flow chart of a smart LED lighting system.As a rule, there are two approaches to energy efficient lighting, namely, the use of high efficiency light sources, and the development of smart lighting techniques. An illustration of the latter is the thermal infrared sensing technique, by use of which indoor lights can be switched on/off automatically when there is somebody/nobody present. On top of that, a lighting system can be made adaptive, such that the indoor brightness can be maintained at a constant level taking into account the contribution of outdoor sunshine. As indicated by statistics, lighting, air conditioning and the rest account for 33%, 50% and 17% of energy consumption, respectively.

Since the late 1960s and early 1970s, developed countries started to develop green lighting technologies for ecological concerns.A great challenge to be faced is the electrical wiring problem when try to build an energy efficient lighting system in an old building. Is there a way to get the job done, but not to rewire the whole house? The answer is affirmative. A solution to this problem is the use of short range wireless communication techniques, namely, Bluetooth, IEEE 802.11 WiFi and infrared. For instance, the residence lighting can be controlled by an IR remote control. There are multiple remote Brefeldin_A controls in most residences, and a universal remote control is a must such that any of the home appliances can be controlled by such single piece [2].A wide variety of sensors, including IR, ultrasonic, light, illumination, voice, and Hall sensors, can be integrated into an MCU-based LED lighting system. In this manner, various types of detected signals can be processed in such a way that an LED lighting system can be operated in a smart way.