What is a Raspberry Pi? A Raspberry Pi, or RPi for short, is a small computer that some models measure about 3.4″x2.1″x0.7″. It can be used in all kinds of projects, from robots to media servers and even air quality monitors! In addition, you will need one if you want to do any kind of hardware project with your Arduino, as they are both micro-computers and will work together seamlessly!
Use soldering iron if you want to connect the wires and pins, or use a breadboard when you want to make more complex circuits.