There is a glut of different single board computers on the market, with more being added to the list yearly. They are the foundation of many recent electronics projects, providing rich feature sets that let us build everything from robots to automated homes, and everything in between. While each version is outfitted with some impressive hardware, they are not a catch-all solution for every project, which is where add-on (or plug-in) boards take up the slack.
Pi Hats or Bonnets (in the UK) provide expansion and upgrade options to their respective platforms, such as adding additional GPIO, audio/video capabilities, relays, motor drives, expanded communication options and a host of others.
There is a wealth of amazing and helpful add-on boards that could fill a book, likewise for the amount of SBCs that are on the market. That said, this roundup will cover expansion options for the Raspberry Pi platforms. While there are plenty “Hats” available on the market, these were chosen for their unique functionalities and their increased development options.
1: Sense Hat – $30
(Image credit: Raspberry Pi )
The Raspberry Pi Foundation designed the Sense Hat for British ESA Astronaut Tim Peake’s first (AstroPi) mission aboard the ISS. It’s a great little board that outfits the Pi (1/2/3) with an expanded sensor suite that includes a gyroscope, accelerometer, magnetometer, temperature, barometric pressure, and humidity. It also consists of an 8×8 RGB LED matrix, a 5-button joystick, and can be programmed using Python. The Foundation even has AstroPi libraries available free on their project webpage .