You sit down with a hot coffee, blink, and suddenly it is stone cold. We all hate that moment. But a new DIY invention solves this by forcing you to drink before it is too late. This smart coaster does not just track your sips; it gets angry if you ignore it.
The technology behind the nagging
We have all been there at some point in our daily lives. You pour a fresh cup of coffee or a crisp glass of water and sit down at your computer to start working. You get lost in your tasks, emails, and spreadsheets. Hours pass by in a blur. You finally reach for your drink only to find it unpleasantly lukewarm. It is a small tragedy that happens in offices everywhere. For maker Lennox Low, this daily annoyance became the spark for a brilliant engineering project.
Low realized that relying on pure willpower to drink water was simply not working. We all try to be healthy, but focus often drifts elsewhere. Apps on phones are easy to ignore because we can just swipe the notification away. Sticky notes eventually blend into the background until we do not even see them anymore. The solution required something more physical and harder to ignore. The result is a custom-built smart coaster powered by an ESP32 microcontroller that actively monitors the weight of your glass.
This device solves two problems at once with one clever design. It helps forgetful water drinkers hit their hydration goals by reminding them to sip. It also saves tea and coffee lovers from the deep disappointment of a cold mug. By tracking the physical object on your desk, it bridges the gap between digital reminders and the real world. It turns a passive object into an active participant in your health.
How the coaster detects every sip
The magic of this device lies in how it interprets weight changes on the surface. Most smart coasters on the market just tell you if a cup is present or check the temperature. This project goes a step further by analyzing the fluctuations in mass to understand your specific actions. It needs to know the difference between you taking a drink and you refilling the glass.
When you place your glass on the coaster, the system records the initial weight as a baseline. It then constantly monitors for any changes in pressure. If you pick up the glass and place it back down lighter than before, the coaster registers this as a sip. The software then calculates the difference and adds that volume to your daily hydration log. This allows for passive tracking without you needing to input data manually into an app.
The system is smart enough to distinguish between a sip and a refill. This logic is crucial for accurate data. If the glass returns to the coaster heavier than it was when it left, the software understands you have added more liquid. It resets the current tracking level for that glass to the new weight. This ensures your hydration stats remain accurate throughout the day, even if you top up your coffee three times.
The feature that makes it impossible to ignore
Passive tracking is useful, but it does not actually force you to change your behavior. You could easily ignore a hydration log just like you ignore a phone notification. The true genius of this project is its aggressive notification system. Low designed the coaster to be intentionally annoying when necessary. The device has a built-in timer that resets every time you take a sip.
If you go too long without drinking, the coaster decides it is time to intervene. It starts with a visual cue. First, a light on the device turns angry red to catch your peripheral vision. This is a gentle nudge to remind you that your drink is waiting. However, if you are deep in focus, you might miss the light.
If you continue to ignore the visual cue, the coaster escalates the situation. It begins to beep. It will not stop pestering you until you physically lift the glass and take a drink. This creates a behavioral loop that is hard to break. The annoyance factor forces you to hydrate just to make the machine stop, which eventually builds a healthy habit. It effectively gamifies hydration by making the consequence of dehydration an immediate auditory nuisance rather than a vague long-term health issue.
Why hardware beats software for habits
This project highlights a growing trend in the maker community where physical hardware solves problems that software cannot. We are drowning in software notifications. Smartphone apps fail because they are trapped inside a screen full of other distractions like social media and email. A physical object on your desk has a presence that an app icon lacks.
Using the ESP32 platform makes this technology accessible and affordable for creators. It demonstrates how simple sensors, when combined with clever code, can manage our biological needs better than we can ourselves. The coaster acts as a dedicated guardian for your hydration. It does not do anything else. It does not check your email or play music. Its sole purpose is to make sure you drink.
Whether you are trying to drink eight glasses of water a day or just want to finish your tea while it is hot, this little robot is the desk companion you did not know you needed. We often think of smart home technology as complex systems for lighting or security. However, sometimes the most impactful innovations are the small, dedicated devices that do one simple thing perfectly. In this case, that thing is making sure you drink your water before it becomes a warm, sad disappointment.
Lennox Low has created a device that blends utility with just the right amount of irritation to change behavior. By turning hydration into a physical interaction rather than a mental chore, this smart coaster proves that technology can actually be helpful in our daily lives. It might be annoying when it beeps at you, but your body will thank you for the hydration in the long run.
What do you think about technology that nags you to be healthy? Would you put this on your desk, or would the beeping drive you crazy? Share this article with your friends and let us know your thoughts.
