With the help of an Arduino Uno, moisture sensor, water pump, and some parts from DigiKey, 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.