Build a DIY Google Voice HAT for Your Raspberry Pi

If you’re a Raspberry Pi enthusiast looking to add voice‑enabled capabilities, the official Google AIY Projects Kit Voice HAT is an excellent starting point. While Google offered the kit for free in MagPi Magazine Issue 57, it has not yet entered the retail market. This guide walks you through creating a cost‑effective, fully compatible custom Voice HAT using the same components as the original kit.

What You’ll Need

• Raspberry Pi (any model with I2S support)
• Voice HAT components (microphone array, amplifier, I2C EEPROM)
• 5 V power supply for the amplifier board
• 3.3 V supply for the microphones

Step 1: Clone the Repository

Open a terminal on your Pi and run:

git clone https://github.com/shivasiddharth/custom-voice-hat

Step 2: Enable I2S and Related Interfaces

Modify the boot configuration:

sudo nano /boot/config.txt

Uncomment these lines:

#dtparam=i2s=on
#dtparam=i2c_arm=on
#dtparam=spi=on
#dtparam=audio=on

Add the following entry:

dtparam=i2c_vc=on

Save, exit, and reboot.

Step 3: Verify the HAT Folder

cd /proc/device-tree/

After reboot, confirm a hat directory exists.

Step 4: Flash the EEPROM

Navigate to the EEPROM utilities and run the flasher:

cd /home/pi/custom-voice-hat/eepromutils
sudo chmod +x ./eepflash.sh
sudo ./eepflash.sh -w -f=voicehat.eep -t=24c32

Step 5: Update the Kernel

sudo apt-get update
sudo apt-get install raspberrypi-kernel

Reboot to apply changes:

sudo reboot

Step 6: Wire the HAT

Once the HAT is detected in /proc/device-tree/, shut down the Pi and follow the wiring diagram included in the repository. Important: Power the amplifier board with 5 V and the microphones with 3.3 V.

Step 7: Configure Audio Settings

Navigate to the audio configuration scripts:

cd /home/pi/custom-voice-hat/audio-config/scripts/

Make them executable and run the setup:

sudo chmod +x ./custom-voice-hat.sh
sudo chmod +x ./install-i2s.sh
sudo ./custom-voice-hat.sh
sudo ./install-i2s.sh

Continue running custom-voice-hat.sh until you see the ".bak" notification. Reboot once completed.

Congratulations! Your Raspberry Pi now supports full voice functionality comparable to the official Google Voice HAT.

For more detailed instructions and troubleshooting, visit the GitHub repository.