Jeremy Cook Converts an Old Keurig Coffee Maker Into an Automatic Plant Watering Machine

Raise your hand if you’ve ever purchased a new house plant and then ended up with a very dead house plant within a week or two because you forgot to water it. If your hand is up, then you may want to consider some sort of automatic plant watering system. There are many options on the market, and most of them are quite affordable at around $50 or so. But Jeremy Cook happened to have an old Keurig coffee maker sitting around unused, and was able to convert it into an automatic plant watering machine using just a few affordable components.

The Keurig used for this project had provided a good decade of service before giving up the ghost. Cook (a writer here at Hackster) was able to get it working again, but during the process he noticed that it had become a bit gross inside. He and his wife decided to purchase a new Keurig machine for their coffee instead of trying to thoroughly clean the old and well-used machine, but Cook couldn’t bear to just throw that old machine away. Instead, he decided to give it a new purpose as an automatic watering system for a single small house plant.

The only original functionality that Cook really needed was the water dispenser, which consists of the water reservoir and a water pump. A house plant obviously doesn’t have any need for hot water or coffee, which means the heating element doesn’t need to be used. It did, however, need to dispense water at pre-determined intervals — a function that this particular Keurig model doesn’t have. To add it, Cook put a Raspberry Pi Zero W inside of the Keurig machine (attached to a 3D-printed mount). It’s programmed with a Python script to spin the water pump motor via the Raspberry Pi’s GPIO pins at specific times or when given a command. A moisture sensor can detect when watering is needed, and pushing the "brew" button will dispense. The result is an automatic watering system built with upcycled parts and an inexpensive single-board computer.