How hot is the water coming out of your tap? Knowing that the water in their apartment gets “crazy hot,” redditor [AEvans28] opted to whip up a visual water temperature display to warn them off when things get a bit spicy.
This neat little device is sequestered away inside an Altoids mint tin — an oft-used, multi-purpose case for makers. Inside sits an ATtiny85 microcontroller — re-calibrated using an Arduino UNO to a more household temperature scale ranging from dark blue to flashing red — with additional room for a switch, while the 10k ohm NTC thermristor and RGB LED are functionally strapped to the kitchen faucet using electrical tape. The setup is responsive and clearly shows how quickly [AEvans28]’s water heats up.
This is version 1.5 — 1.0 rusted out, protect your projects, people! — and a forthcoming 2.0 will feature a smoother transition between colors. In the meantime, [AEvans28] had made his ATTtny code available here for anyone else similarly maligned by scalding tap water. If you are more concerned about the temperature of your wine, but don’t have the room for an appropriate cellar, get serious with this DIY satand-in.