Raspberry Pi Foundation launched the Raspberry Pi Zero on 26th November 2015, taking the IT world by surprise by releasing it secretly at a price of just $5, along with including a free Raspberry Pi Zero for those who were lucky enough to get a copy of that month's MagPie magazine. Needless to say, these tiny computers sold out quickly and, to this day, customers are still limited to purchasing just one device per order from the suppliers who stock them.
In April 2016, a new version of the Pi Zero was launched; a camera port was added to this model, enabling enthusiasts to build super small camera projects and hacks using their Raspberry Pi Zero computers.
The newest and latest version of Raspberry Pi Zero is Pi Zero W. It adds to the second generation of Pi Zero by now including the same Wi-Fi and Bluetooth on-board chip, which was introduced on Pi 3. This makes Pi Zero W a great choice of computer for our projects in this book; it has enough power to deliver what we want, and GPIO pins allow us to connect to and control all manner of devices (as we will see!); and we now have a means to connect to this computer, while it is hidden away in a piece of clothing!
With this in mind, I will be making use of Pi Zero W for all of the projects in this book. If you cannot get your hands on one, don't worry; all these projects will work fine with any Raspberry Pi computer from the model B+ upwards.