[Rick] had a problem. His garage refrigerator was tasked with a critical duty—keeping refreshing beverages at low temperature. Unfortunately, it had failed—the condenser was forever running, or not running at all. The beverages were either frozen, or lukewarm, regardless of the thermostat setting. There was nothing for it—the controller had to be rebuilt from scratch.

Thankfully, [Rick]’s junk drawer was obliging. He was able to find an Arduino Uno R4, complete with WiFi connectivity courtesy of the ESP32 microcontroller onboard. This was paired with a DHT11 sensor, which provided temperature and humidity measurements. [Rick] began testing the hardware by spitting out temperature readings on the Uno’s LED matrix.

Once that was working, the microcontroller had to be given control over the fridge itself. This was achieved by programming it to activate a Kasa brand smart plug, which could switch mains power to the fridge as needed. The Uno simply emulated the action of the Kasa phone app to switch the smart plug on and off to control the fridge’s temperature, with the fridge essentially running flat out whenever it was switched on. The Uno also logs temperature to a server so [Rick] can make sure temperatures remain in the proper range.

We’ve seen some great beverage-cooling hacks over the years. If you’ve mastered your own hacky methods of keeping the colas chilled, don’t hesitate to let us know on the tipsline.

It’s said that beauty and art can be found anywhere, as long as you look for it. The latest art project from [dmitry] both looks in unassuming places for that beauty, and projects what it sees for everyone to view. Like most of his projects, it’s able to produce its artwork in a very unconventional way. This particular project uses water as a lens, and by heating and cooling the water it produces a changing image.

The art installation uses a Peltier cooler to periodically freeze the water that’s being used as a lens. When light is projected through the frozen water onto a screen, the heat from the light melts the water and changes the projected image. The machine uses an Arduino and a Raspberry Pi in order to control the Peliter cooler and move the lens on top of the cooler to be frozen. Once frozen, it’s moved again into the path of the light in order to show an image through the lens.

[dmitry] intended the project to be a take on the cyclical nature of a substance from one state to another, and this is a very creative and interesting way of going about it. Of course, [dmitry]’s work always exhibits the same high build quality and interesting perspective, like his recent project which created music from the core samples of the deepest hole ever drilled.