Assignment 8: Fan-Powered Door Chimes

State Machine: Distance Door Bells

Problem: Door bells are usually intrusive noises. They are sudden and loud and usually disturb the peace, or at least peace hoped for, in your home. In addition, most door bells only have two states: at the door or not. Because of this, guests usually must wait at the door for the host to arrive at the door and the host usually must drop everything they’re doing immediately to go and get the door. Is there a way to create a simple doorbell that does not alarm everyone in the house and also gives you a sense of where people are relative to the door?

General solution: A door chime system that created more calming/less disturbing sounds in order to alert the host. The system can also relay more information, namely, how far away someone is from the door to symbolize how much time the host has to finish whatever they are doing before making their guest wait at the door. As a guest gets closer and closer to the door, the chimes will grow louder and louder. Also, doorbells are traditionally known, at least at my house, for alarming dogs and setting them into a fit. To avoid this, these chimes can also be turned to a “do not disturb” mode for when people aren’t home or are asleep, so they chimes do not make noise to disturb the peace.

Proof of Concept: My system utilized the following components:

  • Ultrasonic Sensor: used to measure distance to simulate guest proximity to door
  • Fan: the driver of the chimes, causing them to knock together and create noise depending on the fan speed determined by the distance sensor
    • Transistor: acts as a voltage gate to allow the fan to be controlled at various speeds
    • Fan has 4 different states of sound production: just fan noise with no air movement, light air with light chimes, medium air with medium chimes, heavy air with heavy chimes
  • Push button: acts as an interrupt that changes the “mode” of the doorbell


Files above, but after potentially shorting Chance’s computers and digging deeper into my own arduino issues… I am going to skip the video portion to get those things figured out for now.


I'm Conor and I'm a 2nd-year grad student at the Entertainment Technology Center. I got my undergrad in Mechanical Engineering (with minors in Design and Psychology) from the University of Notre Dame. I am really interested in theme park design, experience design and integrating physical components into XR experiences. I have some Arduino programming experience (it's been a few years), have designed different experiences for ADA compliance, and have full use of the ETC woodshop.

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