What is Arduino?
Arduino is an open-source electronics platform based on easy-to-use hardware and software. Arduino boards are able to read inputs - light on a sensor, a finger on a button, or a Twitter message - and turn it into an output - activating a motor, turning on an LED, publishing something online. You can tell your board what to do by sending a set of instructions to the microcontroller on the board. To do so you use the Arduino programming language (based on Wiring), and the Arduino Software (IDE), based on Processing.
Arduino is an easy platform to interface with sensors and actuators.
and the software:
In this example an ultrasonic sensor is hooked up to an Arduino that allows it to measure distance while an LCD screen is used to communicate this distance back to the user.
This can be described in a schematic such as the diagram below (example).
Work on the challenges provided in the workshop
Please note that you can also code Arduino in your browser and store your projects in the cloud. For this workshop however we will be using the Arduino IDE installed on your laptops. Just beware that Arduino has a lot of official and 3rd party tools to make coding and collaboration easier. For instance entire circuits can be prototyped virtually in platforms such as 123Circuits or arduino can be programmed with a visual programming language with Visuino.com.
On the main page of the Physical Computing workshop there is a chapter Resources listing links for further reference.
Additionally several (e-)books on Arduino are available.