Device that never leaves a light left on after everyone's left or shuts a light off with any inside.
For this device I identified a pet peeve of mine: when people do not turn off lights upon leaving a room. This device is used next to a light switch to track the number of people in and out of room so that the light switch automatically turns on and off. I also identified another pet peeve that this solves: when you sit in a room with automatic lights for too long and they shut off on you and you have to wave your arms around to get them back on.
For this process I first created a bilateral door counter using two ultrasonic sensors and depending on which is tripped first, the inside of outside, it tracks whether it was the person entering or exiting. After this worked with and was confirmed by the serial monitor stating number of people I used the screen to track this. I used the screen because it was a way for me to check if it was working and also was informative to users. The next and final step was to add a servo motor that is oriented down, when the people count ascends to 1 it flips up 180 degrees, and when the people count descends to 0 it flips down 180 to turn the switch off.
For fabrication I created a box by laser cutting plywood, then account for extruding parts by measuring and layering those. To attach this to the wall I use velcro command strips for the box and the servo motor. I initially intended for the servo to by apart of the box but having it unattached allows the user to place it as close to the switch as possible and makes it more usable for different switches. The box has a hinge on top to view or edit the components. In a more final version I would like to implement a more secure way to attach the device to the wall.
Progress Images
