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Explore the Best Raspberry Pi Expansion Boards : Enhance Your Projects with Our Curated HAT List

TheRaspberry Pi is an awesome platform for learning and experimentation. In its first 11 years it has helped many users learn to code, build robots and monitor the location of the International Space Station (they’ve even been onboard the ISS!), and so much more. But to make the most of the Pi, it helps to have the right expansion board. Originally the Raspberry Pi didn’t have a standard definition for boards. The first official expansion, 2012’sGertBoard was larger than the Pi itself. But all this changed when the HAT (hardware attached on top) standard was introduced along with the Raspberry Pi B+ in 2014. It provided a standardized means,similar to Arduino’s Shields , to connect theRaspberry Pi’s set of 40 GPIO pins (increased from 26 to 40 with the B+) to add-ons providing functionality such as lights, motors, sensors and fans without a mess of wires. The HAT standard follows a similar standard used byArduino boards, where they are called “shields”. HATs are an easy way to add extra features without connecting a mess of wires.

There are hundreds, if not thousands of Raspberry Pi HATs on the market and most of them will work with any model of Pi that has 40 pins, which is every model launched from 2014, though you’ll need to attach theGPIO pins to the Pi Zero.
If you intend to use a HAT with theRaspberry Pi 400 then you will also need a breakout connector, such asPimoroni’s Flat HAT Hacker HAT . If you are feeling adventurous, you can even use someHATs with the original 26 pin GPIO models of Raspberry Pi or theRaspberry Pi Pico W . Other Raspberry Pi alternative boards may claim compatibility with HATs, but do your research before connecting as you may inadvertently damage the boards.

To help you choose, we’ve listed the best Raspberry Pi HATs that we have personally tested, grouped by their use case. These expansion boards can be used for everything from general learning to implementing A.I. via Machine Learning. Or you could just build your own Raspberry Pi powered robot to explore the world around us.

The release of theRaspberry Pi 5 surprised many, including HAT and addon creators who are working to patch their boards for use with the latest Raspberry Pi. The issues that they face are two-fold. Firstly there are changes to howPython works on the Debian 12 Bookworm-based OS . The changes boil down to that we can no longer install Python modules directly to the OS. Instead we need to install intovirtual environments. Secondly, due to the new RP1 chip, how the GPIO is accessed has changed. This has lead to many HATs being incompatible with the Pi 5, for now. Progress is being made by developers who maintain the software behind our favorite boards.

Raspberry Pi has released the first HAT+ standard board [PDF] , the[PDF] . But we are still some way from a wave of new boards that will use this standard.

Raspberry Pi HAT Shopping Tips

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When buying a Raspberry Pi HAT, ask yourself these questions:

What is the HAT for? If it’s for a particular project, does it do what you need it for? If it is for a child, does the HAT have enough features to grow with their learning?
Does the HAT work with your Raspberry Pi? Every Raspberry Pi since 2014’s Raspberry Pi B+ features a 40 pin GPIO, and all HAT boards are designed for that. Raspberry Pi Zero W users may want to look for pHAT, smaller HATs designed for Zero form factor. If you are using aRaspberry Pi 400 then you will needa breakout board to access the GPIO.
How can the HAT be programmed? Does it come with a Python module, and is it user friendly? Can it be programmed in another language? Is there documentation to support your learning?
Does the HAT use all your pins? While most Raspberry Pi HATs physically cover all 40 GPIO pins, many of them allow a pass-through so you can use many of those pins with other devices or even another HAT stacked on top of the first one.

Best Raspberry Pi HATs at a glance:

Pimoroni Inventor HAT Mini
Build HAT
Pimoroni IO Expander
Pimoroni Picade X
Raspberry Pi Sense HAT
Pimoroni Breakout Garden
Raspberry Pi PoE HAT
Google AIY Voice HAT
Cyntech Pibrella
Adafruit Perma-Proto HAT
Adafruit Capacitive Touch HAT
Raspberry Pi M.2 HAT+

## Best Raspberry Pi HATs

(Image credit: Tom’s Hardware)

1. Pimoroni Inventor HAT Mini

Best General Purpose Raspberry Pi HAT

Specifications

Seller: Pimoroni

MSRP: $24

Compatibility: All 40 pin models

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Reasons to buy

Great form factor

Lots of features

Easy to use

Simple Python module

Reasons to avoid

Non-Zero boards require a header extension

Taking over from Pimoroni’s Explorer HAT Pro is a tough task, but this little board does an excellent job of incorporating lots of features into a small package.

Providing connections for up to four servos, two DC motors (via a DRV8833 motor controller), eight tiny, but bright RGB “NeoPixel” LEDs and anaudio connection, this little board is packed full of fun.

All of this hardware is nothing without a companion software package and Pimoroni has stepped up to the plate and delivered. The Python module is easy to use and abstracts away the complexities of controlling the various forms of hardware.

The Inventor HAT Mini is a great board at a low price. Well worth your time and money.

MORE: Pimoroni Inventor HAT Mini Review

(Image credit: Tom’s Hardware)