Idea
For this assignment, I came up with a simple idea of creating a personal space invasion detector. The circuit has two mode, turned on and off using digital input (switch), the space detection using analog input (photoresistor). If the hand comes to close the person, the yellow light will dim. I use the yellow LED because it normally symbolizes happiness, which means when it dims, the person becomes less happy because someone invaded his personal space.
Implementation
I drew a circuit of the detector, including 2 LEDs, 1 photoresistor, 1 resistor and 1 switch. The switch I use is the rectangular one with three connecting points. If points 1-2 are connected, turn on the red LED, if 2-3 are connected, turn on yellow LED (connected to photoresistor).
Video