The "Green" Light Switch is a device that's meant to allow people to manage and save energy on lighting in the environments where they work. The general concept is a box that's placed over your light switch and mechanically flips the switch to turn the lights on or off depending on the condition of the room. The goal of this device was to find an optimal way to ensure the lights are turned off when a room is not being used so no energy is wasted. We realized there was an existing attempt at solving this problem with motion detector light controllers, yet these are set with a timer system and often either stay on for a while once someone has left a room or turn off while a person is still in a room but hasn't passed by the motion sensor in a while. Our solution was different. The "Green" Light Switch encourages the use of natural lighting (from windows) in work environments by only turning on the lights if it detects someone is in a room and that the natural lighting in the room is below a workable threshold. Our innovative light switch only turns and keeps the lights on when necessary. Watch the video directly below to see how it works!
The way our device works is by taking inputs from a sound sensor, proximity sensor, and light sensor (which were all included in the Adafruit Circuit Playground Express we used to build this device) to tell if the specific conditions are met to have the lights on or off. The diagram below depicts the order in which these inputs are taken and what the result is based on the condition.
Images of the different sides of the device (click the images to discover more details)
Images of CAD for the casing of the device as well as its dimensions
The circuit diagrams depicting the sensors used and how the servo motor interacts with the pre-existing lightswitch
Images of the Python code we used to program the AdaFruit Circuit Playground Express (with annotations directly relating to the conditions required and actions taken by the device)
