The Raspberry Pi is an awesome platform for learning and experimentation. We can learn to code, build robots, monitor the location of the International Space Station, and so much more. But to make the most of the Pi, it helps to have the right HAT (hardware attached on top). HATs are expansion boards, introduced along with the Raspberry Pi B+ in 2014, that connect to the Raspberry Pi’s set of 40 GPIO pins and easily add functionality such as lights, motors, sensors and fans without 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 the GPIO pins to the Pi Zero. (opens in new tab)
If you intend to use a HAT with the new Raspberry Pi 400 then you will also need a breakout connector, such as Pimoroni's Flat HAT Hacker HAT. If you are feeling adventurous, you can even use some HATs with the original 26 pin GPIO models of Raspberry Pi.
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 building arcade cabinets or implementing A.I. via Machine Learning.
Raspberry Pi HAT Shopping Tips
When buying a Raspberry Pi HAT, ask yourself these questions:
Best Raspberry Pi HATs at a glance:
Best Raspberry Pi HATs
1. Pimoroni Explorer HAT Pro
Great general purpose board for electronics
Lots of project options from one board
Analog-to-digital conversion
Simple Python module
Reasons to avoid
Covers every GPIO pin with no pass thru
For general purpose experiments in electronics nothing can beat Pimoroni's Explorer range of boards. We've used the Explorer HAT Pro since 2015 and it remains a powerful add-on for the Raspberry Pi. The Explorer HAT Pro is an all in one electronics lab which fits neatly on to the GPIO. Four capacitive touch pads and four crocodile clip pads offer touch and capacitive input which can turn conductive objects, such as fruit and aluminum foil into fun inputs.
Buffered 5v tolerant inputs and outputs and provide easy use of common electronic components you would normally need an Arduino board for. Perhaps most importantly, it has four built-in analog inputs so you can attach analog devices such as potentiometers and joysticks without the need for an additional analog-to-digital converter chip (something the Pi lacks on its own).
Two built in motor controllers mean we can build a robot using this board. To top it all off there is a built in breadboard on which we can build our experiments. We do lose access to all of the GPIO pins when using the Explorer HAT Pro , but considering that this board provides so many different inputs / outputs and is designed with beginners in mind, we can forgive this loss.
2. Build HAT
Best Raspberry Pi HAT for Lego Projects
Works with all Raspberry Pi
Powers the Raspberry Pi
Can be battery powered
Reasons to avoid
Incompatible with some HATs
Merging Lego and Raspberry Pi together is a genius idea. Build HAT works with all 40-pin models of Raspberry Pi and it enables the use of LPF2 components, such as motors and sensors from the Spike, Mindstorms and Technic range of kits.
With four LPF2 connectors, we can easily add a combination of Lego components to build robots and elaborate sensor-controlled devices. When we tested Build HAT we found that the accompanying Python library abstracts the complexities of using the components, providing a frictionless approach to Python powered Lego projects. This is a great board to introduce coding concepts to children who have grown past block based coding, as the use of Lego provides a familiar construction material.
3. Pimoroni IO Expander
ADC and 14 Extra GPIO Pins for Your Pi
Add 14 GPIO pins
Reasons to avoid
If not used with Breakout Garden HAT, soldering is required.
Whether you need more GPIO pins or your project needs analog inputs, the IO Expander from Pimoroni is a cost effective and simple means to do just that for $10. The IO Expander provides up to 14 extra GPIO pins, with all offering digital input / output, six with PWM (Pulse Width Modulation), useful for precise control of motors, and eight analog inputs to be used with electronic components such as potentiometers.
The Pimoroni IO Expander is not a typical add on board for the Raspberry Pi. Measuring a mere 1 x 0.9 inch (25 x 23mm) the board has only five connections which are made to the GPIO. The need for so few connections is due to the IO Expander using I2C, a two wire serial communication protocol. These five pins can be soldered to using the included male / female header pins, then placed atop the I2C pins of the GPIO. This design is not accidental, rather it is deliberate as the IO Expander is part of Pimoroni’s Breakout Garden range of boards.
There is nothing not to like about the Pimoroni IO Expander, which is small in size but big in features and it should be in the bits box of every Raspberry Pi enthusiast.
4. Pimoroni Picade X HAT
Best Raspberry Pi HAT for Retro Gaming
Compatibility: All 40 pin models, for best results Pi 3 and 4
Today's Best Deals
Everything we need for an arcade build in one board
Provides power to the Pi
Reasons to avoid
Blocks CPU and raises temperature
If you want to build a retro arcade machine, complete with an arcade joystick and buttons, the Pimoroni Picade X HAT is the board to get. The X HAT has all the connectors you need to attach one joystick, and up to 12 buttons, including those for functions such as adding a coin or 1UP button.
The added “Hack Header” provides a connection to the I2C interface, handy for adding extra components. Picade X HAT also provides sound using an I2S interface via the GPIO and a 3W mono amplifier outputs the audio to an external speaker (sold separately). The Picade X HAT has a USB port that it uses to provide power both to the Pi itself and to any speakers.
The latest version of the Picade X HAT uses a Type-C connector, which means that it provides enough juice to power either a Raspberry Pi 4 or an earlier model. Older versions of the X HAT, which may still be on sale, use a microUSB connector that only has enough juice for a Pi 3 or earlier.
After you install a one-line script, the Picade X HAT works flawlessly in popular emulation platforms such as RetroPie and Lakka, both of which see it as a keyboard where you just assign each button to a function (like you’d assign a keyboard key).
One potential issue with the Picade X HAT is that, because gaming puts a load on your processor and the board covers your CPU, it can trap in heat, which is a particular problem for Raspberry Pi 4s. If you use a stacker to raise the height, you can put a fan or heat sink below it.
5. Raspberry Pi Sense HAT
Best Raspberry Pi HAT for Learning, Experiments
Lots of sensors for experiments
Works with Python and Scratch
Reasons to avoid
Covers every GPIO pin and prevents easy access to free pins
Despite being over five years old, Sense HAT is still the best all-around Raspberry Pi HAT for learning. Featuring onboard temperature, humidity, air pressure, accelerometer, gyroscope and magnetometer sensors can be used in science experiments via Python and Scratch. A joystick and 8 x 8 LED matrix can be used to make and control simple games.
If you’re working with kids or just want to have fun getting started with a Pi, the Sense HAT should be at the top of your shopping list. The amount of learning offered by this board is superb. Two Sense HATs live aboard the International Space Station and every year students compete to have their code run on it . . . from the AstroPi, a Raspberry Pi in space.
6. Pimoroni Breakout Garden
Best Raspberry Pi HAT for Using Multiple Sensors
Easy, hot swappable modules
Simple Python module
Reasons to avoid
Breakout I2C boards can be expensive
The I2C interface is hidden as part of the Raspberry Pi GPIO. It is an alternative configuration of the standard GPIO and it offers advanced users a four wire interface for multiple devices, connected in a chain. Breakout Garden is a Raspberry Pi HAT which offers a simple means to connect I2C devices.
Additional breakout boards, ranging from LED matrices to air quality sensors and thermal cameras slot into one of the six slots and can be easily used thanks to a custom Python 3 library. This is a highly configurable and simple to use base for citizen science projects.
7. Raspberry Pi PoE HAT
Best Raspberry Pi HAT for Power over Ethernet
MSRP: $29.92
Single wire solution for power and networking
Provides cooling for the Pi
Reasons to avoid
Requires a PoE capable network
Only works on Pi 3B+ and later
The Raspberry Pi PoE (Power over Ethernet) HAT is compatible only with the 3B+ and 4 and provides a single wire solution for network and powering your project. This Raspberry Pi HAT is extremely useful for installing projects in remote locations, such as in your garden or shopping mall.
Using this HAT also provides us with a cooling fan, useful for the Raspberry Pi in general as it keeps the temperature down, but more so since the release of the Raspberry Pi 4. The PoE HAT fits atop all of the GPIO pins, but an included extension header means that we can connect another board on topsure that there is clearance for the fan.
8. Google AIY Voice Kit (with HAT)
Best Raspberry Pi HAT for Artificial Intelligence
Modular parts which fit together easily
Easy to build your first AI assistant
Reasons to avoid
Initial purchase is expensive
If you have ever wanted to learn Artificial Intelligence or build your own voice assistant, such as Siri, Alexa or Google, then Google’s Aiy Voice Kit is for you. The Voice Kit comes in a simple card box, but inside there is a Raspberry Pi HAT which has connections for the speaker, button, microphone and servos.
To accompany this Raspberry Pi HAT is a robust Python 3 module which simplifies the task of creating a voice assistant. This HAT can be used with all 40 pin models of Raspberry Pi including the Pi Zero W. A great kit to start your AI learning!
9. Cyntech Pibrella
Best Raspberry Pi HAT for Younger Makers
Compatible with Python and Scratch
Reasons to avoid
An old board which is hard to come by
Designed for older Raspberry Pi
Pibrella, released when the Raspberry Pi GPIO had only 26 pins, is the ideal way to introduce electronics and programming to young minds. Designed for the original Raspberry Pi, but compatible with all models of Pi, Pibrella provides us with a simple push button, three LEDs and a buzzer. Four inputs, and four outputs can be used with external components, including motors.
To program Pibrella we can use Python or Scratch and quickly bring a project to life. This Raspberry Pi HAT can be used to build simple robotic projects and teach logic, core concepts using the LEDs. The ideal board for kids who just want to build their first project.
10. Adafruit Perma-Proto HAT
Best for Creating Your Own Raspberry Pi HATs
Ideal way to start building your own circuits
Reasons to avoid
Expensive for multiple boards
If you are a seasoned Raspberry Pi hacker, then you may have already taken your first steps into electronics using a breadboard. But where do you go from here? The answer is to create your own circuit board.
The Adafruit Perma-Proto HAT works with 40 pin GPIO Pi and provides a place where you can solder your own components to build a circuit. LEDs, buttons, motor drivers and more. This is a great way to take your skills to the next level and learn how to layout a circuit.
11. Adafruit Capacitive Touch HAT
Best Raspberry Pi HAT for Inspiring Creativity
Great fun to use
Reasons to avoid
Python module is a little lucky
Lots of wires for all 12 connections
Did you know that a banana can be an instrument? A watermelon can be a controller for a game? This and lots more is made possible using the Adafruit Capacitive Touch HAT. For use with all 40pin GPIO Pi, this HAT has 12 crocodile clip connectors which can be connected to objects that are conductive.
When a conductive object is touched, the Adafruit Capacitive Touch HAT detects a change in voltage and this triggers an action in your Python code. The classic project for this Raspberry Pi HAT is the Banana Piano which sees each banana representing a key. Touch the banana and the note for that key is played. The Python code is a little tricky to get right, but the fun with this board is limitless.
Finding Discounts on the Best Raspberry Pi HATs
Whether you're shopping for one of the best Raspberry Pi HATs or one that didn't quite make our list, you may find savings by checking out the latest SparkFun promo codes, Newegg promo codes, Amazon promo codes or Micro Center coupons.
This content was originally published here.
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