Learn about six HAT components you can attach to a Raspberry Pi for a wide range of additional capabilities. 

HATS, not unlike Arduino shields and Adafruit FeatherWings, can add a variety of sensors, displays, and capabilities to a Raspberry Pi. While some improve its strengths, others give the single-board computer new features. 

For your consideration, take a look at six HAT components below that could be a great addition to any project. 

The Sense HAT

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A Sense HAT. Image courtesy of Adafruit

The Raspberry Pi Sense HAT has several integrated sensors along with an 8x8 LED Matrix to display data. 

Its several sensors helpfully provide accurate readings that conveniently display on LEDs. 

A joystick is also integrated into this board, so the user can smoothly control scripts. It's a fitting package for any prototyping tasks or projects where a significant amount of environmental information is being collected. 

For a specific project using the Sense HAT, check out our Get Started with Sense HAT: Automatically Log Weather Sensor Data in a Spreadsheet with an Astro Pi Station article! 

Features:

  • Accelerometer
  • 3D gyroscope
  • Magnetometer
  • Pressure Sensor
  • Humidity Sensor 
  • Temperature Sensor
  • Joystick
  • 8x8 LED Matrix 

Adafruit DC and Stepper Motor HAT

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Adafruit DC and Stepper Motor HAT. Image courtesy of Adafruit.

Does the idea of equipping your Raspberry Pi with the brains of a robot appeal to you? Then the Adafruit DC and Stepper Motor HAT is the perfect addition for you. Since it enables your Pi to run either with four DC motors or two stepper motors. 

Not only does it come with a fully dedicated PWM chip, it also includes polarity protection. 

To seal the deal, this HAT can wear other HATs on top of it. 

According to its manufacturer, Adafruit, it can stack up to thirty-two HATs on top of itself and control 64 stepper or 125 DC motors. 

Features:

  • 4 H-Bridges: TB6612 chipset provides 1.2A per bridge with thermal shutdown protection, internal kickback protection diodes. Capable of running motors on 4.5VDC to 13.5VDC.
  • Up to 4 bi-directional DC motors with individual 8-bit speed selection (so, about 0.5% resolution)
  • Up to 2 stepper motors (unipolar or bipolar) with single coil, double coil, interleaved or micro-stepping.
  • Big terminal block connectors to easily hook up wires (18-26AWG) and power.
  • Polarity protected 2-pin terminal block and jumper to connect external 5-12VDC power.

The Automation HAT

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Automation HAT for Raspberry Pi. Image courtesy of Adafruit

If you're ready to make your home a little smarter, this is a good place to start. Utilizing this HAT's built-in relays, your Pi can easily control different devices. 

It also includes LEDs you can program and indicators you can use to monitor your project. 

Features:

  • 3 x 24V @ 2A relays (NC and NO terminals)
  • 3 x 12-bit ADC @ 0-24V (±2% accuracy)
  • 3 x 24V tolerant buffered inputs
  • 3 x 24V tolerant sinking outputs
  • 15 x channel indicator LEDs
  • 1 x 12-bit ADC @ 0-3.3V
  • 3.5mm screw terminals
  • Power, Comms, and Warn! LED indicators
  • SPI, TX (#14), RX (#15), #25 pins broken out

The 3D Tracking Flick! HAT

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3D Tracking Flick! HAT. Image courtesy of Digikey.

The Flick! HAT adds touchpad capability and a gesture sensor to your Pi. If you need to distinguish between touches and taps for user input, this HAT can easily meet that request. 

You can also swipe on it in different directions, turn invisible knobs and even draw freely without actually having to touch it. 

Features:

  • 3D tracking
  • Gesture sensing up to 15 cm
  • Touch and Tap sensing
  • Communicates with the Raspberry Pi via I2C
  • Full software libraries (fully open-source code)

The PiJuice HAT

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A PiJuice HAT. Image courtesy of Digikey

The PiJuice HAT decks your microprocessor with a built-in power bank that works while charging simultaneously. 

This can be extremely helpful in projects where heavy actuator use is desired, but just as useful in cases with variable power inputs, such as solar-powered weather monitors. 

Features:

  • Onboard 1820 mAh off the shelf Lipo / LiIon battery for ~4 to 6 hours of constant use (includes support for a larger Lipo Battery of 5000 or 10,000+ mAH to last up to 24+ hrs).
  • Integrated Real Time Clock
  • Onboard intelligent on/off switch
  • Low power deep-sleep state with wake on interrupt/calendar event
  • Programmable multi-colored RGB led (x2) and buttons (x3) with super simple user-configurable options
  • All GPIOs available via stackable header for ease of expandability and connectivity
  • Easily, replaceable battery (compatible with any single cell LiPo or Li-Ion battery).

The Mini Black HAT Hack3r 

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A Mini Black HAT Hack3r. Image courtesy of Adafruit.

Though Raspberry Pi HATs and Arduino shields are a similar concept—the Raspberry Pi can usually only support one HAT at a time as the pins are no longer accessible. 

Using the Mini Black HAT Hack3r, a user can place a HAT onto a Raspberry Pi and still have access to the GPIO. 

This tool allows for two HATs to be equipped or use of any custom devices needed for a project. 

Features:

  • HAT & pHAT spec landing area with PCB standoffs
  • Includes 40 pin GPIO ribbon cable
  • All GPIO pins labeled with function, BCM pin number, and physical pin number
  • Rubber non-slip feet
  • 4 mounting holes
  • Comes pre-assembled.

Keep in mind, the entries in this roundup do not include every component's use or feature. A more exhaustive list can be found for each of the HATs on their product websites.

Will you be using any of the HATs we've covered? Have we missed any great ones? Let us know in the comments! 

Eduardo Pecina
Polyglot Programming Pianist :P