This Annoying Coaster Won’t Let You Ignore Hydration Without a Fight

You’ve heard it a million times: it is important to stay hydrated. So, like the dutiful caretaker of your own body that you are, you go fill up a glass of water and take it back to your desk. Then four hours pass and you look down to realize you haven’t taken a single sip. Dehydration lurks just around the corner, you fool! This Annoying Coaster prevents such danger by refusing to let you ignore your water.

This “coaster” is really just a dressed-up digital scale. Except it is dressed up as a very obnoxious child that won’t stop poking at you. Place your glass on the coaster and it will measure the weight. Each time you pick up the glass to take a drink and then set the glass back down, the coaster measures the weight again. If too much time passes between drinks or the weight is dropping fast enough, the coaster will start trying to get you to hydrate.

It does that primarily through flashing RGB LED lights. Those should be enough to act as a friendly reminder. But if you ignore them and continue walking down that dangerous and, frankly, immoral path towards dehydration, it will blare an alarm at you.

That will be too irritating to ignore, so you’ll either drink some water or throw the coaster in a trash can.

The hardware is simple: just an ESP32 dev board measuring weight through amplified load cells. A small OLED screen shows the status and weight measurements. The indicator lights are on a KY-009 RGB LED module and the alarm buzzer is a buzzer. Those components go in a slim 3D-printed enclosure.

I personally believe that people make too big of a deal about hydration and that your body will tell you when you need water. But if you don’t share my opinion and also like habit-building through abusive motivation, this is the coaster for you.