Learning to Program the Arduino. This article should acquaint you with basic Arduino programming and show you how to write programs that interact with objects in the real world. (A mandatory disclaimer: the last time I really studied electronics was way back in high school, so this article focuses more on the programming aspects, rather than the electronic side of things.) Physical Computing Before I start talking about this really cool thing called Arduino (Italian for "good friend"), let me say a few things about the fascinating subject of physical computing. Physical computing has been defined in various ways, but the central idea seems to be the same: physical computing is concerned with developing software that interacts with the world beyond the host computer through a combination of hardware and software—it's aware of the world, so to speak. Such awareness makes these applications capable of sensing external events and responding to them in a predefined way.
Arduino. Hardware.