Adafruit BrainCraft HAT User Manual

Adafruit BrainCraft HAT - Easy Machine Learning for Raspberry Pi

Created by lady ada

Last updated on 2021-03-03 01:41:38 PM EST

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Guide Contents

Guide Contents Overview Pinouts

Power Display Buttons and Joystick Sound STEMMA QT Connector Digital/Analog Connectors DotStar LEDs Fan

Required Parts Raspberry Pi Computer For Vision projects For Audio Projects Raspberry Pi Setup Step 1 - Burn SD Card Step 2 - Configure log-in access Step 3 - Log in & Enable Internet Step 4 - Update/Upgrade Blinka Setup Audio Setup Install Voicecard software Headphone/Speaker Test Microphone Test Fan Service Setup Display Module Install Installing The 1.54" Kernel Module Kernel Module Troubleshooting

BrainCraft Audio Driver Reinstall

Camera Test Python Usage

Joystick and Button DotStar LEDs GPIO JST connectors

Parts Wiring Code

Stemma QT

Parts Wiring Code

Downloads

Files Schematic Fab Print

Overview

The idea behind the Adafruit BrainCraft HAT is that you’d be able to “craft brains” for Machine Learning on the EDGE, with Microcontrollers & Microcomputers. On ASK AN ENGINEER, our founder & engineer chatted with Pete Warden, the technical lead of the mobile, embedded TensorFlow Group on Google’s Brain team about what would be ideal for a board like this.

And here’s what we designed! The BrainCraft HAT has a 240×240 TFT IPS display for inference output, slots for a camera connector cable for imaging projects, a 5 way joystick and button for UI input, left and right microphones, stereo headphone out, a stereo 1 Watt speaker out, three RGB DotStar LEDs, two 3 pin

STEMMA connectors on PWM pins so they can drive NeoPixels or servos, and Grove/STEMMA/Qwiic I2C port. This will let people build a wide range of audio/video AI projects while also allowing easy plug-in of sensors and robotics!

A controllable mini fan attaches to the bottom, and can be used to keep your Pi cool while doing intense AI inference calculations. Most importantly, there’s an On/Off switch that will completely disable the audio

codec, so that when it's off, there’s no way it's listening to you.

Features:

1.54" IPS TFT display with 240x240 resolution that can show text or video

Stereo speaker ports for audio playback - either text-to-speech, alerts or for creating a voice assistant. Stereo headphone out for audio playback through a stereo system, headphones, or powered speakers.

Stereo microphone input - perfect for making your very own smart home assistants Two 3-pin JST STEMMA connectors that can be used to connect more buttons (https://adafru.it/ICw),

a relay (https://adafru.it/NmC), or even some NeoPixels! (https://adafru.it/Cup) STEMMA QT plug-and-play I2C por t (https://adafru.it/Ft4), can be used with any of our 50+ I2C STEMMA QT boards (https://adafru.it/NmD), or can be used to connect to Grove I2C devices with an adapter cable (https://adafru.it/Ndk).

5-Way Joystick + Button for user interface and control. Three RGB DotStar LEDs for colorful LED feedback.

The STEMMA QT port means you can attach heat image sensors like the Panasonic Grid-

EYE (https://adafru.it/y8d) or MLX90640 (https://adafru.it/NmE). Heat-Sensitive cameras can be used as a

person detector, even in the dark! An external accelerometer can be attached for gesture or vibration sensing such as machinery/industrial predictive maintenance projects

Pinouts

Power

5.0V - Connected to the display backlight

3.3V - Connected to the display power and also the STEMMA QT / Qwiic connector GND - Ground for everything

Display

The display is a 1.54" wide-angle TFT LCD.

MOSI, SCK, GPIO #25, CE0 - These are the display control pins. Note that MISO is not connected, even though it is an SPI pin, because you cannot read back from the display. GPIO #26 - This is the display backlight pin. Used to turn on and off the backlight.

Buttons and Joystick

These pins have a 10K pullup to 3.3V so when the button is pressed or the joystick is moved/pressed, you will read a LOW voltage on these pins.

GPIO#17 - Button GPIO #16 - Joystick select GPIO #22 - Joystick left GPIO #23 - Joystick up GPIO #24 - Joystick right GPIO #27 - Joystick down

Sound

GPIO #18, GPIO#19, GPIO #20, GPIO #21 - I2S Digital Audio. Speakers - The two speaker connectors are located on the bottom in the middle, labeled Right and Left. Plug in

an enclosed speaker (https://adafru.it/uyB) or use a JST 2PH cable to attach custom speakers (https://adafru.it/drM).

Microphones - The two mics are in the middle of each side, labeled Left Mic and Right Mic. Headphones - A headphone jack is located on the bottom right. Use any headphones or Line-Out to another audio system. On/Off Switch - Located on the left, towards the top, switches audio on and off.

STEMMA QT Connector

SCL, SDA - I2C data for the STEMMA QT / Qwiic connector. Not used by buttons or display. Can also use

with Grove sensors with an adapter cable (https://adafru.it/Ndk). Great for quickly adding

sensors or accessories with plug-and-play.

Digital/Analog Connectors

GPIO#12 and GPIO #13 - 3-pin JST digital or analog connectors. Easily connect things like

NeoPixels (https://adafru.it/Cup) or servos (https://adafru.it/FWq) using this 2mm connector. You can also use a generic JST cable to connect to a breadboard. (https://adafru.it/CVg)

DotStar LEDs

Three fully color RGB addressable LEDs can provide feedback or a light show. Uses DotStar protocol (not NeoPixel) so any microcomputer can easily control the lights.

GPIO #5 - DotStar LED data pin. GPIO #6 - Dotstar LED clock pin.

Fan

GPIO #4 - The fan is on this pin.

Required Parts

Before you start, you'll need some parts to make your BrainCraft HAT run! At a minimum you will need

Raspberry Pi Computer

A working Raspberry Pi (Pi 4+ needed for vision projects, any Pi for audio-only projects)

Raspberry Pi 4 Model B - 2 GB RAM

The Raspberry Pi 4 Model B is the newest Raspberry Pi computer made, and the Pi Foundation knows you can always make a good thing better! And what could make the Pi 4 better... $35.00 In Stock

Power supply

Add to Cart

5V 2.5A Switching Power Supply with 20AWG MicroUSB Cable

Our all-in-one 5V 2.5 Amp + MicroUSB cable power adapter is the perfect choice for powering singleboard computers like Raspberry Pi, BeagleBone or anything else that's power... $7.50 In Stock

Add to Cart

Official Raspberry Pi Power Supply 5.1V 3A with USB C

The official Raspberry Pi USB-C power supply is here! And of course, we have 'em in classic Adafruit black! Super fast with just the right amount of cable length to get your Pi 4... $7.95 In Stock

And an SD card. It can be blank or come with software on it.

SD/MicroSD Memory Card (8 GB SDHC)

Add mega-storage in a jiffy using this 8 GB class 4 micro-SD card. It comes with a SD adapter so you can use it with any of our shields or adapters. Preformatted to FAT so it works out... $9.95 In Stock

For Vision projects

you'll also want a Raspberry Pi camera, a long cable (optional) and camera case (optional)

Add to Cart

Raspberry Pi Camera Board v2 - 8 Megapixels

Snap, snap! The Camera v2 is the new official camera board released by the Raspberry Pi Foundation!The Raspberry Pi Camera Board v2 is a high quality 8... $29.95 In Stock

Add to Cart

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Adafruit BrainCraft HAT User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual