US Patent 9927674 Multipurpose controller for multistate windows

“Smart” controllers for windows having controllable optical transitions are described. Controllers with multiple features can sense and adapt to local environmental conditions. Controllers described herein can be integrated with a building management system (BMS) to greatly enhance the BMS's effectiveness at managing local environments in a building. The controllers may have one, two, three or more functions such as powering a smart window, determining the percent transmittance, size, and/or temperature of a smart window, providing wireless communication between the controller and a separate communication node, etc.