If you're a steampunk enthusiast looking to give your bathroom an extra kick, this just might be the project for you. This stylish and functional "vintage" toothbrush timer knows when you've grabbed your toothbrush, and will visually count down two minutes before alerting you when you've brushed long enough.
All you'll need to put one together yourself is a microcontroller (the designer used a ATmega328p), a weight sensor, light bulbs, brass cups and a tray, an alarm clock's chime, and some wood for the base.
It works by reading the weight of the scale. If it ever dips below 3 grams, it'll activate the timer and turn on all of the lamps. For every 20 seconds that passes, one of the lamps will turn off. After 2 minutes, the little alarm clock chime will be struck and a "cool down" period will start, giving you time to get your brush back onto the scale.