This Handy Raspberry Pi-Controlled Water Dispenser Automatically Fills Different Size Bottles

I hate to bring back memories of your crystal-loving aunt’s lectures, but are you drinking enough water? You’d be surprised how many ailments are the result of simple dehydration! In reality, you are probably just fine as long as you’re drinking water whenever you’re thirsty. Your body is pretty good at telling you when it needs to be hydrated, after all. The problem is that you might not always have water handy, which is why it’s a good idea to have a big ol’ jug of the stuff nearby. But refilling water bottles is a pain, so Christopher Lis used a Raspberry Pi to control a water dispenser that automatically fills bottles in a variety of sizes.

Most people fill water bottles in their home using a refrigerator dispenser or the good old fashioned kitchen tap. But standing around while water is pumped into your bottle takes a surprising amount of time. Lis calculated that he spends approximately 15 hours refilling water bottles every year. The obvious solution is to connect a water dispenser to a timer so that you can walk away without fear of overflow. But Lis uses a variety of water bottles in vastly different sizes, from a backpacker-style Nalgene bottle to a massive water bladder. In order to fill each of those completely without overfilling, Lis used a Raspberry Pi to control the timing. Four different buttons are used to select the desired volume and the Raspberry Pi automatically pumps out that amount of water.

Lis teaches online programming courses, but he had never worked on a physical computing project before. That meant there was a bit of a learning curve, but he was able to code the control software in JavaScript — a language he was already familiar with. The water comes from an auxiliary water line in the kitchen. The Raspberry Pi simply opens up a valve for the required amount of time corresponding to which button has been pressed. Some nifty LED lighting adds a bit of dramatic flair and an indication that the water is still being dispensed. The frame of the dispenser was 3D-printed in PLA and the LEDs are diffused by a chunk of molded epoxy. The dispenser was mounted to a wall that was cutout so that the Raspberry Pi, water line, and power supply could be hidden on the backside. A bit of sanding and spray painting gave the dispenser a nice finished look so it doesn’t look out of place in the kitchen. Now all Lis has to do when he wants to fill a water bottle is place it beneath the dispenser and push the corresponding button, saving literally minutes every day!