Introduction
If you have a first-generation Google Home Mini sitting idle because you prefer a voice assistant that doesn’t send your data to the cloud, there’s an open-hardware drop-in board that can give it a second life. For about $85, this board replaces the original internals and turns the speaker into a smart speaker powered by Home Assistant. This guide walks you through the conversion process, from gathering tools to final setup.
What You Need
Before you start, make sure you have the following items ready:
- Google Home Mini (1st generation) – Required as the donor device.
- Drop-in replacement board – An open-hardware board compatible with the Mini’s case and speaker. It typically costs $85 and includes an ESP32 or similar microcontroller with a microphone and speaker interface.
- Small Phillips screwdriver – For opening the speaker enclosure.
- Plastic pry tool or spudger – To safely separate the casing without damage.
- MicroSD card (at least 16GB) – To store the Home Assistant operating system image.
- MicroSD card reader – For flashing the image onto the card.
- USB-C power cable – The board uses the same power input as the original (5V, 2A recommended).
- Computer with internet connection – To download the Home Assistant image and configure it.
Step-by-Step Guide
Step 1: Prepare the Google Home Mini
Unplug the device and place it on a soft cloth to prevent scratches. Using the plastic pry tool, gently separate the top fabric cover from the base. The cover is held by adhesive or clips; work your way around carefully. Once the top is removed, you’ll see the main speaker driver and the original circuit board.
Step 2: Remove the Original Electronics
Disconnect the small ribbon cables that connect the board to the speaker, microphone, and LED ring. Then unscrew the mounting screws holding the original PCB in place (typically two or three small Phillips screws). Lift the board out and set it aside (you can recycle it or keep as a spare). Be careful not to damage the speaker cone or the microphone membrane.
Step 3: Install the Drop‑in Board
Take your replacement board and align it with the mounting holes in the Mini’s chassis. Most boards are designed to fit exactly where the original sat. Secure it with the screws you removed earlier. Reconnect the speaker and microphone cables to the corresponding ports on the new board (polarity usually doesn’t matter for the speaker, but follow the board’s documentation). The LED ring cable may need to be connected if the board supports it; otherwise, the LED may not light up.
Step 4: Reassemble the Enclosure
Before closing, double-check that all cables are firmly attached and that no wires are pinched. Place the top cover back onto the base and press gently until it snaps into place. Some models require you to reapply adhesive; if so, use a thin strip of double‑sided tape along the rim. Let the assembly rest for a minute to ensure a firm hold.
Step 5: Flash Home Assistant onto the MicroSD Card
Insert the microSD card into your computer. Download the latest Home Assistant OS image from the official website (choose the version for your board, often labelled as “Home Assistant Yellow” or “Raspberry Pi” if the board uses a similar chip). Use a tool like Balena Etcher to write the image onto the card. Once done, safely eject the card.
Step 6: Power On and Initial Setup
Insert the microSD card into the slot on the drop‑in board (if available) or connect via USB if the board has its own flash storage. Plug the USB-C power cable into the Mini. The device will boot and the LED (if connected) may flash. wait 2–3 minutes for the system to initialize. Then, from a computer or phone on the same network, open a browser and go to homeassistant.local:8123 or find the IP address in your router’s DHCP list.
Step 7: Configure Home Assistant
Follow the on‑screen wizard to create an account, set your location, and detect your smart home devices. To use the voice assistant features, you need to enable a local voice pipeline. Go to Settings > Voice Assistants and add a new assistant. Choose the microphone input (the Mini’s built‑in mic) and select a language model — options like Whisper (local) or a cloud service. For offline operation, use the Assist feature with a local text‑to‑speech engine. After setup, you can say “Hey Assistant” or a custom wake word and control your home without sending data to Google.
Tips for Success
- Double‑check compatibility: This guide specifically works for the 1st‑generation Google Home Mini. Later models have different hardware layouts and are not supported by this board.
- Use a quality power supply: A 2A USB‑C charger ensures stable operation. Under‑powering may cause random reboots or audio distortion.
- Upgrade the microcontroller firmware: Some boards ship with older firmware. Check the open‑hardware repository for updates that improve audio quality or fix bugs.
- Consider a wired Ethernet connection: If your Wi‑Fi is spotty, some boards support an Ethernet hat or can be connected via a USB‑to‑Ethernet adapter. This ensures reliable voice commands.
- Join the community: The open‑hardware project has an active forum and Discord channel. If you run into issues, other users can help with board‑specific wiring or software tweaks.
- Keep the original parts: If you ever want to revert, you can reinstall the original board and restore your Mini to its factory state (though the Google Assistant service may require a factory reset).
With this conversion, your Google Home Mini becomes a privacy‑focused smart speaker that runs entirely on your local Home Assistant instance. The $85 investment gives you a compact, always‑on voice assistant without cloud dependency — perfect for smart home enthusiasts who value data sovereignty.