Harbinger of the Internet of Dings
Last year, I built the first version of what I call the "Raspberry Pi Bell Slapper." It was named that because it used a servo and a metal arm to slap the top of the bell in response to a stimuli—in this case, an email from a donation notification system for a local non-profit radio station.
This year, that same radio station had another one of their fund-raisers (a radiothon), and to celebrate, I thought I'd do the thing justice, with a better circuit (using a solenoid instead of a servo) and a 3D printed enclosure. And this is the result:
There is a Raspberry Pi Zero W with a custom solenoid control HAT on top inside the case to the left, and the solenoid right up against the bell, which is mounted on the right.
I also posted a video on YouTube exploring the project in detail: The Raspberry Pi IoT Notification Bell.