Our first task will be to install a copy of the Arduino IDE (Integrated Development Environment) on our Raspberry Pi. The Arduino IDE is where we will write sketches—these are Arduino programs. The IDE also allows us to upload the code directly to the Arduino Uno.
The software can be found at the official Arduino website: http://arduino.cc/en/main/software
The installation instructions cover a variety of operating systems, including Linux, Mac OSX, and Windows. For the Raspberry Pi you will want the Linux instructions.
You can, of course, install the IDE onto a separate computer and use this for updating the Arduino if you wish.
The following section will provide a quick overview of the Linux installation process.