Multiway switching controller design using FPGA

Multiway switching has become nowadays quite frequently used in building wiring. It can be defined as an interconnection of two or more electrical switches in order to control an electrical load from more than one location. Although the electrical load is often a lamp, electrical outlets, fans, pumps, heaters or other appliances, it can also be controlled by multiway switching. However, in this paper we will deal only with lighting systems. Special switches are required to implement the system (three-way and four-way switches) that have additional contacts, and extra wires must be run between them. In this way the light can be controlled from dierent spots, e.g. the top and bottom of stairs or the end of a long hallway. Externally there is a resemblance between these switches and the standard single-pole ones. Extra connections make possible the control of a circuit from multiple locations. By connecting one or more four-way switches in-line, with three-way switches at either end, the light can be controlled from three or more locations. Toggling any switch changes the state of the light from o to on, or from on to o. We would like to introduce a solution in this paper, based on FPGA for the mentioned system and using HDL. The aim is to attain a high level of generalization by applying any (even quite large) number of switches and lights.