A Pushup-Activated Candy Vault
Tim van de Vathorst created a candy vault that opens when you do 10 pushups.
As of this writing, the October trick-or-treating season has come and gone, leaving many of us with large amount of uneaten candy (or perhaps empty wrappers). If you do enjoy the "occasional" sweet treat, and would like to slow down and/or justify your consumption, then the “Vault for Fit People” by Tim van de Vathorst could be the perfect solution.
The device uses a Raspberry Pi single-board computer, along with a Pi Camera, to capture video of candy and/or fitness seekers doing pushups. This is processed with the help of Google’s MediaPipe library for joint detection, and it measures the angles between the shoulder, elbow, and wrist to determine one’s pushup state. If the elbow angle is at roughly 90º, that signifies a down position, while the arms straightened out at 180º means the participant has pushed up.
If the Pi counts 10 pushup transitions, it then opens the vault door, which is actuated using a small servo motor and a rack-and-pinion mechanism. A wheel on the front of this wooden mini-vault spins during the lock/unlock process, which is quite a nice effect. Van de Vathorst also came up with a mobile app for the device, and a power bank makes it an entirely mobile candy protector.
The build process is outlined in the video below, along with some real-world testing. It looks like it was a lot of fun to create and try out. Code is available on GitHub, while the vault design is available for download here if you'd like to examine the details.