The best HATs for your Raspberry Pi

A HAT will remind you of the English word "hat", in fact they are just that, hats to insert into the GPIO pins of the Raspberry Pi and extend its capabilities. Kind of like the existing shields or modules for Arduino, they serve the same function. But in reality HAT is an acronym for Hardware Attached on Topi.e. hardware connected on top and acting as an add-on extending the capabilities of the Raspi.

As with Arduino, the success of the Raspberry Pi has led to many developers interested in creating add-ons for the board. These third parties have manufactured a large number of HATs such as LCDs, ADC/DACs, sensor boards, buttons, breadboards, motors, etc... And in this article we will make a compilation of the most interesting HATs that we can find on the market, with their characteristics and functionalities.

It must be said that the Raspberry Pi A and Raspberry Pi B had GPIO pins to extend their capabilities, but changes had to be made to the Linux files for the board to interact with the added hardware, as it had no auto-detection capability. You had to mess around with the terminal and sometimes it might not work properly or be limited. However, from Raspberry Pi B+ onwardsThe boards have been designed with these HATs in mind. The new models now accept HATs and make life much easier for users.

HATs will be automatically detected and the Raspberry Pi will configure the GPIOs to work properly, add the drivers of the commented board and the user will not have to do anything. And for this, there are two dedicated pins that are responsible for the configuration, these are the GPIO ID_SD and ID_SC. They provide the information to the Raspi that is stored in an EEPROM memory included by the HAT manufacturer and that will help to modify the "device tree" of the system.

HATs to extend connectivity

Adafruit Ultimate GPS

• Functionality: GPS board for the Raspberry Pi, adding geolocation and other GPS functionality to your board.
• Characteristics: GPS integrated in the PCB. LED indicator. Integrated antenna. RTC.
• Price: approx. €50
• Buy on Amazon

NAVIO+ Autopilot HAT and NAVIO2

• Functionality: Kit or board to create robot and drone projects with piloting function. The latest version of this board is NAVIO2, which includes some improvements compared to the NAVIO+ board.
• Characteristics: Integrated piloting functionalities. Supports GPS/Glonass/Beidou signal thanks to the U-blox M8N chip. Compatible with Linux APM (ArduPilot) platform. Includes MPU9250 9DOF IMU. Support for USB/WiFi/3G connectivity. MAVLink support. MS5611 barometer. Power monitoring with ADS1115 ADC. MB85RC FRAM storage. EEPROM. PCA9685 to generate digital PWM signals. RBG LED indication.
• Price: approx. 300€.
• Buy on Amazon

Energenie Pi-mote

• Functionality: British board for the control of low-cost household appliances. It is therefore intended for home automation, allowing remote control of the sockets in our home.
• Characteristics: Software modulation, compatible with EnerGine plugs and cable.
• Price: approx. 15€.
• Buy on Amazon

Cluster HAT

• Functionality: Increase the computational capacity of the Raspberry Pi A+, B+, 2 and 3 or simulate a small cluster.
• Characteristics: It has 4 slots for Raspberry Pi Zero boards, with USB connection and Controller Serial Console (FTDI Basic) connector.
• Price: approx. €35

Pimoroni Rainbow HAT

• Functionality: Designed for the world of the internet of things or IoT, with sensors, inputs and screens for Android. It can be used as a weather station, a clock, timer, stopwatch, status light, etc...
• Characteristics: It features multicolour LEDs, 15-segment displays to form letters, symbols and numbers, piezo buzzer, pressure sensor, temperature sensor, and the ability to control servo motors, capacitive touch buttons, and Atmel QT1070 and HT16K33 controller chips.
• Price: approx. €25
• Buy on Amazon

Bear IoT pHAT Network

• Functionality: RedBear has created this board for the IoT and for the Raspberry Pi Zero, giving this small board connectivity.
• Characteristics: It has 802.11n (2.4Ghz) WiFi connectivity and Bluetooth 4.1.
• Price: approx. 10€.
• Buy on Amazon

HATs for prototyping

Adafruit Perma-Prototype

• Functionality: Protoboard or development board. For inserting electronic components without soldering. So you can easily assemble and disassemble your electronic projects.
• Characteristics: Protoboard PCB. Includes EEPROM memory chip so you can program your configurations following the Pi Foundation specifications for HATs.
• Price: approx. 10€.
• Buy on Amazon

Propeller HAT

• Functionality: Protoboard for projects based on the Parallax Propeller microcontroller.
• Characteristics: Parallax Propeller microprocessor. Protoboard board to build your projects. Compatible with Propeller IDE for native language development (SPIN).
• Price: approx. 21€.
• Buy on Amazon

Pimoroni Explorer HAT

• Functionality: Prototyping board for Raspberry Pi.
• Characteristics: Power connections. Mini board. Capacitive buttons.
• Price: approx. 15€.
• Buy on Amazon

RasPiO Pro HAT

• Functionality: Prototyping board for Raspberry Pi with numbered connections to have your projects well ordered.
• Characteristics: Power and GPIO connections as well as mini breadboard in the centre with 72 connection points.
• Price: approx. 20€.

HATs with input and output devices

Display-O-Tron

• Functionality: RBG LCD display.
• Characteristics: Display 16×3 ASCII characters and RGB colour.
• Price: approx. €40
• Buy on Amazon

Adafruit PiTFT

• Functionality: TFT colour screen.
• Characteristics: There are several versions of this TFT colour display. One touch-sensitive and one non-touch-sensitive and in several different sizes.
• Price: approx. 25-65€.
• Buy on Amazon:
  • 3.5″ touch
  • 2.8″ touch
  • 2,4″ touch
  • 2,2″

Pi-DAC+

• Functionality: HD sound card for excellent sound on your Raspi.
• Characteristics: Digital audio connections. Full-HD support. EEPROM for saving configurations.
• Price: approx. €50
• Buy on Amazon

Pi-DigiAMP+

• Functionality: Turn your Raspi into a Hi-Fi sound system.
• Characteristics: Amplification and Full-HD audio system thanks to the Texas Instruments TAS5756m chip. Controllable thanks to the Linux ALSA module. ESD protection and EEPROM memory for storing configurations.
• Price: approx. €80
• Buy on Amazon

Sense HAT

• Functionality: It is a Raspberry Pi addon created by the foundation for the 2015 International Space Station Astro Pi mission, but now we can all enjoy it.
• Characteristics: It has an 8×8 RGB LED matrix, gyroscope, accelerometer, magnetometer, temperature sensor, barometer, and humidity sensor. All manageable from a specific Python library.
• Price: approx. 42€.
• Buy on Amazon

Analog Zero

• Functionality: Board designed for the Raspberry Pi Zero, created by RasPiO. In this case it extends the analogue connection capabilities of the Zero. With it you can make from weather stations, voltmeters, digital thermometers, potentiometers, control voltages or analogue signals of some kind, read analogue sensors, etc...
• Characteristics: Capable of reading up to 8 analogue inputs at once.
• Price: approx. 11€.
• Buy on Amazon

Adafruit Capacitive Touch HAT

• Functionality: Capacitive controller for working with capacitive sensors to operate devices or create a musical instrument.
• Characteristics: It contains 12 capacitive keys to interact with and an MPR121 microcontroller.
• Price: approx. €8
• Buy on Amazon

PaPiRus ePapper eInk Screen HAT

• Functionality: Display module for Raspberry Pi.
• Characteristics: Capable of carrying screens from 1.44″ up to 2.7″, and unlike normal screens it mimics ink on paper, which gives a rather elegant touch.
• Price: approx. €70
• Buy on Amazon

Traffic HAT

• Functionality: It allows you to learn about GPIOs in a quick and very basic way thanks to this traffic light.
• Characteristics: LED lights controllable from the Raspberry Pi GPIOs.
• Price: approx. 5€.
• Buy on Amazon

HATs for engines and robotics

Raspi Robot Board

• Functionality: Control for electric motors.
• Characteristics: Integrates DC and stepper compatible motor controllers.
• Price: approx. 30€.
• Buy on Amazon

Adafruit PWM/Servo

• Functionality: Control for servomotors and digital PWM outputs.
• Characteristics: It includes a 16-channel PWM controller capable of controlling up to 16 servos at a time or other PWM-connected devices.
• Price: approx. €25
• Buy on Amazon

MotoZero

• Functionality: Module for the Raspberry Pi Zero, capable of controlling DC motors.
• Characteristics: Capable of controlling four motors independently thanks to its 4 controller chips. It has 5 terminal blocks, 1 capacitor, and 40 GPIO pins.
• Price: approx. 10€.

Adafruit DC & Stepper Motor HAT

• Functionality: Advanced module for electronic and stepper motors for Raspberry Pi.
• Characteristics: PCB with controllers for 4 independent DC motors and 2 stepper motors with PWM speed control.
• Price: approx. 30€.
• Buy on Amazon

Pan-Tilt HAT

• Functionality: Ideal for a mini TV camera, mobile lighting, or to implement it on top of a robot as a mobile arm, etc...
• Characteristics: Movable arm thanks to two servomotors (pan & tilt) to move the camera thanks to the integrated controller.
• Price: approx. 10€.
• Buy on Amazon

Automation HAT

• Functionality: Module to control and monitor the home. It is compatible with the Pi Zero.
• Characteristics: It has 3 relays, 4 ADCs, 3 24v inputs, 15 LEDs, screw terminals for connections, SPI, etc...
• Price: approx. 30€.
• Buy on Amazon

HATs miscellaneous

Unicorn HAT

• Functionality: Configurable screen to create colour effects.
• Characteristics: 64 RGB LEDs. EEPROM memory for saving configurations. Configurable thanks to a Python API.
• Price: approx. €29
• Buy on Amazon

Skywriter HAT

• Functionality: Motion and gesture control for Raspberry Pi.
• Characteristics: Contains position sensors for operating your board. It detects simple gestures like touches and 3D positions. Together with the Python API you can control your projects without keyboards or mice.
• Price: approx. 29€.
• Buy on Amazon

Piano HAT

• Functionality: Minipiano for Raspberry Pi.
• Characteristics: Contains 18 sensitive buttons and 16 piano keys. LEDs. Octave buttons. Controllers to unleash your creativity and synthesize sounds in combination with Python.
• Price: approx. 20€.
• Buy on Amazon

Black HAT Hack3r

• Functionality: Tool for developers of HATs and hardware for the Raspberry Pi that allows you to debug your projects.
• Characteristics: It contains connections for PCB boards of your projects and circuitry necessary for debugging them.
• Price: approx. 29€.
• Buy on Amazon

Picade HAT

• Functionality: Turn your Raspberry Pi into a retro gaming console.
• Characteristics: It features DAC I2S audio with 3w mono amplifier, secure on/off system, microUSB, 4 inputs for digital joysticks, 6 inputs for game buttons, 4 outputs for utility buttons, a power switch and breakout for other GPIOs.
• Price: approx. 29€.
• Buy on Amazon

Drum HAT

• Functionality: Digital touch drum.
• Characteristics: 8 advanced capacitive touch pads with LED indicators to make sonic beats and be controlled with the Raspi.
• Price: approx. 15€.
• Buy on Amazon

Adafruit Animated Eyes

• Functionality: Modules that simulate animated eyes that will move. Compatible with Pi B+, Pi 2, Pi3 and Pi Zero or higher.
• Characteristics: Controller capable of controlling two 128×128 pixel OLED or TFT LCD screens on which the eyes will be projected.
• Price: approx. 8€.
• Buy on Amazon

Raspberry Pi boards and other add-ons

Although they are not HATs, I wanted to include them in this article to give extra functionality to our Raspberry Pi. These are boards that also have the same purpose as the HATs, only they don't have the auto-detection capability of the HATs. The resemblance makes the difference between the concept HAT and Plate becomes blurred, but it is easy to distinguish them, especially because the plates, although they are compatible with other models (because the 26 main GPIOs have been maintained since the beginning and have been added other extra for new models), are more intended for boards with model A and B:

Adafruit Prototyping Pi Plate

• Functionality: Have a breadboard to easily assemble and disassemble your electronic circuits. No soldering, just using the connections established on its surface.
• Characteristics: Contains pads for inserting electronic components. Peripheral connections for power supply and other external connections. Female connectors to supply the inserted components.
• Price: approx. 17€.
• Buy on Amazon

Pi-Plates MOTORplate

• Functionality: One of the most powerful controllers for electric motors.
• Characteristics: Allows the combination of two stepper motors or one stepper motor and two DC motors. It has two driver chips for the stepper and DC motors. It has a dedicated micro-controller integrated on the board. It also has DIPs for motor speed selection and power selection. It allows the connection of external sensors (such as tachometers, etc...).
• Price: approx. 31€.

Pi-Plates DAQCplate

• Functionality: Extends the I/O capabilities of the Raspberry Pi.
• Characteristics: 7 digital outputs for connection of external devices (high current LEDs, relays, etc...). 8 analogue inputs for sensors. 8 digital inputs. 2 analogue outputs. 7 integrated LEDs for general purpose. Reprogramming button. Programmable bi-colour LED. Address selector and microcontroller.
• Price: approx. 31€.

Lightberry HD

 

Although it is neither a palte nor a HAT, the Lightberry HD is a peripheral that connects to the GPIO pins of the Raspi to complement it and so we have included it.

• Functionality: LED lighting system for your TV.
• Features: Fastening strap. Converter and connector cable. To make it work, it is necessary to install software to control the luminaire, which is already configured and installed in our MEGA kit Media Center and in our ready-made distribution.
• Price: approx. €100
• Buy Lightberry HD for TVs from 20 to 54 inches at ComoHacer.eu
• Buy Lightberry HD for 55 to 75 inch TVs at ComoHacer.eu

I hope you found the article helpful, both in terms of getting to know the world of HATs and to help you make your choice if you were undecided. Don't forget to leave your comments and questions, and if there are any missing boards or HATs that we can add, we will be happy to review them.