With the help of an Arduino Uno, moisture sensor, water pump, and some parts from Digi-Key, your plants will remain hydrated while you're away.

You can connect Arduino sensors, actuators, and other ICs with the digital inputs and outputs (digital I/O) on the Arduino for useful things, such as reading switch inputs, lighting indicators, and controlling relay outputs.

Make your own sous-vide machine with an Arduino and a rice cooker in a weekend.