10 fun things you can connect to a Raspberry Pi's GPIO pins

The Raspberry Pi's main claim to fame is being a whole computer on a single circuit board, complete with a capable ARM chip. But its biggest party trick is how expandable it is, with a handy 40-pin general-purpose input/output interface (or GPIO for short).

This is a feature of all Raspberry Pi models, and it's key to some of the most interesting and fun Raspberry Pi projects.

Sense HAT

The Sense HAT is perhaps one of the best add-on boards to start with in terms of bang for your buck. With it, you get an add-on that can monitor temperature, humidity, atmospheric pressure, color, orientation, and movement. You also get an 8x8 RGB LED matrix that you can use to display information from these sensors (or anything else you want). Lastly, you also get a five-button joystick.

The sense HAT can be found for around $33 online and is powered by the Raspberry Pi it's connected to.

Build HAT

Easily one of the most fun boards you can buy, the Build HAT is designed to interface with up to four LEGO Technic motors and sensors from the LEGO Education SPIKE collection. The HAT has a few optional accessories you might want to pick up, including the SPIKE Prime Expansion Set (for connecting your Raspberry Pi to LEGO bricks) and the Build HAT Power Supply for delivering enough power for the Pi, HAT, and any connected devices.

You can pick up a Build HAT for $25, with the power supply costing another $15.

Pimoroni Picade X HAT

Pimoroni's Picade X HAT with USB-C is an essential component for anyone looking to turn their Raspberry Pi into an arcade cabinet. It gives you joystick and button inputs (joysticks and buttons sold separately), a built-in digital-to-analog converter (DAC), and a soft power switch.

You can pick up a Picade X HAT for around $20.

DigiAMP+

Looking to turn your Raspberry Pi into a full-blown hi-fi? The DigiAMP+ HAT delivers up to 35W per channel to two speakers via its mounted screw terminals. This HAT requires a 12-24V DC external power source (via a barrel connector), which itself will also power your Raspberry Pi.

You can pick up this little amplifier add-on for around $30.

Pimoroni Pan-Tilt HAT

Looking to turn your Raspberry Pi into a CCTV camera? Maybe you're building a Raspberry Pi remote control car and want the ability to shift the camera's perspective? The Pan-Tilt HAT includes horizontal and vertical motion servos plus a Python library to streamline programming your creation.

There's no camera included, but you can pick up the tilt kit for around $42 (while stocks last).

Donkeycar RC HAT

Donkeycar is an open-source self-driving racing car project. You should join your local meetup group if you're interested in building and racing self-driving RC cars, but there's nothing stopping you from going it alone and converting a regular RC car with the help of the Donkeycar RC HAT .

This $19 add-on board will allow you to put the project's Python library to good use by using images from cameras and LiDAR, GPS coordinates, steering and throttle inputs, and much more.

Mini GPIO Xmas Tree

Arguably the most pointless yet unashamedly fun add-on on this list, the GPIO Xmas Tree includes five LEDs that you can control via Scratch or Python. It connects to the first six inner GPIO pins on just about any Pi unit and is powered entirely by your Pi.

Despite its basic premise, the GPIO Xmas tree is a fun introduction to simple programming and only costs £4 (around $5.30).

Inky Impression E-Ink displays

Turn your Raspberry Pi into a picture frame, eReader, or a smart home dashboard using a beautiful color E-Ink display. These displays come in a range of sizes, with the smaller 7.3-inch model costing around $85 and the much larger 13.3-inch version pushing the price up to $275.

The display comes with four side-mounted buttons, a GPIO extension header for use with a full-sized Pi, standoffs for attaching the display to a board, plus an expansion header for attaching other devices. It has a full refresh time of 12 seconds and is powered entirely by whatever Pi it's attached to.

HyperPixel 2.1 Round Display

What's more fun than an angular 16:9, 4:3, or square display? A round one, of course! The HyperPixel 2.1 Round is a $62 high-resolution 480x480 display with a 60Hz refresh rate and wide viewing angles. It uses IPS technology, works as a touch interface, and is compatible with any Raspberry Pi that has a GPIO interface.

HyperPixel supplies separate display and touch drivers, though it should be noted that the display uses all GPIO pins, which means you can't necessarily use this display with other HATs (except sensors via the I2C interface on the back of the display).

Navio2

If you fancy throwing a ton of money at a Raspberry Pi project, check out the Navio2 . This is an autopilot drone controller that includes satellite tracking (GPS, GLONASS, Beidou, Galileo, SBAS), motor and servo control via a radio-controlled co-processor, a whole heap of sensors for detecting motion and motion, and a bunch of ports for completing your project.

At $199, it's not cheap, but by the time you're finished, you'll have an amazing toy to play with.

---

These are just ten of many weird and wonderful add-on boards you can get for your Raspberry Pi. If you're looking to do more with your Pi's USB ports, check out some fun USB accessories you can plug in there instead .