The Raspberry Pi is what’s known as a Single Board Computer. It’s small enough to fit it in the palm of your hand, weighs almost nothing, costs around $35, but is a real, full computer, capable of serving as a workstation, a server, a media center or the heart of an automation system.
One of the things that makes this a great board for makers is the bank of pins along one side, known as General Purpose Input Output, or GPIO pins. The beauty of these pins lie in their simplicity—they’re simple pins that you can read from or control. For example, you can connect a simple pushbutton to two of the pins, then write some code to do something in response to it.
You can use a couple of other pins as an output. The most basic example lights up an LED, but lighting a simple LED is essentially no different than firing a relay that can turn on a light in your house, or a machine in your factory or ring an alarm bell.
We’ll be doing a lot with Raspberry Pi, so you can find all of the projects in our Raspberry Pi category.