The Raspberry Pi is incredibly versatile on its own, but its true potential is unlocked with Hardware Attached on Top (HAT) extensions. These add-ons connect directly to the GPIO pins, expanding the Pi’s capabilities significantly. This article explores eight remarkable HATs that can transform your Raspberry Pi into a multimedia center, a robotics platform, and much more. While focusing on the Raspberry Pi 4, most of these HATs are compatible with other models, including the new Pi 5. Always verify compatibility before purchasing.
A DAC allows you to connect the Pi to passive or active speakers or a stereo system, transforming it into a streaming device.
Enhance Audio with a DAC
One of the easiest and most impactful upgrades is a Digital-to-Analog Converter (DAC). The Raspberry Pi Foundation offers several DACs that instantly improve audio quality. The Digi AMP+ is ideal for passive speakers, delivering up to 35 watts per channel, perfect for a home stereo setup. For active speakers, the Raspberry Pi DAC or DAC+ offer classic banana plug connections, allowing you to connect directly to speakers or a stereo system’s AUX input. Combined with the right software, these DACs transform the Raspberry Pi into a powerful streaming device.
The Lego HAT empowers you to control Lego sensors and motors with your Raspberry Pi.
Unleash Your Inner Lego Master with the Build HAT
The Raspberry Pi Build HAT is a must-have for Lego enthusiasts, enabling control of up to four motors and sensors, including Lego Mindstorms components. You can even find Lego boards designed to seamlessly integrate the HAT into your Lego creations. The Build HAT supports most components with an LPF2 connection. Check the official product page for detailed compatibility information. Note: An external power supply (sold separately) is required to operate motors, as the onboard power is insufficient. A comprehensive Python library is available for controlling various sensors, opening up a world of creative possibilities.
This compact board enables the Raspberry Pi to communicate with Zigbee smart home devices.
Centralize Your Smart Home with Raspbee II
The Raspbee II HAT provides a centralized smart home control solution through your Raspberry Pi. This compact board communicates with Zigbee devices, eliminating the need for multiple manufacturer gateways. It even includes a battery slot for real-time clock (RTC) functionality. While Zigbee is the communication protocol, the control logic relies on software, so check device compatibility with the chosen software before purchasing.
Turn your Raspberry Pi into a mini gaming console with the Game HAT.
Retro Gaming with the Game HAT
Transform your Raspberry Pi into a portable retro gaming console with the Waveshare Game HAT. This unique HAT features a 3.5-inch, 480×320 pixel display with 60 FPS, perfect for classic games. Integrated speakers, a headphone jack, and familiar gamepad buttons complete the console experience. While battery life is limited to approximately one hour of active gameplay, the Game HAT offers a fun and engaging retro gaming experience.
The Braincraft HAT provides a platform for exploring machine learning on the Raspberry Pi.
Explore Machine Learning with the Braincraft HAT
The Braincraft HAT opens the door to exciting machine learning projects, but requires a deeper understanding of the subject matter. This HAT is designed for both hobbyists and professionals interested in edge computing. It features a 240×240 TFT IPS display, camera connections, a joystick, microphones, audio outputs, and various sensors. While not for a quick weekend project, the Braincraft HAT offers a powerful platform for exploring the world of machine learning.
Interactive Touch Displays
Waveshare offers a range of touch displays that transform the Raspberry Pi into a compact, interactive device. The 3.5-inch resistive display is a true HAT, easily attached to the GPIO pins and comes with a stylus. For a larger, more responsive experience, the 5-inch capacitive touch display connects via the camera ribbon cable, offering 800×480 resolution and excellent driver support. While not a true HAT, this design leaves the GPIO pins accessible for other extensions.
The PiJuice HAT provides an external power supply for your Raspberry Pi, ideal for portable projects.
Power Up with Essential HATs
For portable projects, reliable power is crucial. The PiJuice HAT provides a battery solution with a real-time clock, ensuring accurate timekeeping. Alternatively, the official PoE+ HAT allows you to power your Raspberry Pi via an Ethernet cable, ideal for network switch setups. Ensure your network switch provides sufficient voltage before purchasing.
The PoE+ HAT powers your Raspberry Pi through an Ethernet cable connected to a compatible network switch.
Dive into Robotics with the Trilobot
The Pimoroni Trilobot is a comprehensive robotics starter kit, providing a platform for learning and experimentation. While not a HAT in the traditional sense, the Raspberry Pi is integrated into the Trilobot chassis, which includes motors, ultrasonic sensors, and RGB LEDs. Additional components, like a Raspberry Pi camera and external power supply, are required for full functionality. The Trilobot is a great educational tool for learning the fundamentals of robotics.
Before You Buy
Consider these factors before purchasing a HAT:
- Case Compatibility: HATs increase the overall height of the Raspberry Pi, potentially requiring a new case.
- Raspberry Pi Compatibility: Ensure the HAT is mechanically and electrically compatible with your specific Raspberry Pi model.
- Software Support: Verify the availability of drivers, libraries (typically Python), tutorials, and sample applications to ensure you can effectively utilize the HAT’s features.
