Revive Your Google Home Mini with an $85 Open Hardware Board for Home Assistant

Introduction

Smart speakers like the Google Home Mini have brought voice control into millions of homes. However, many users are increasingly concerned about privacy and the reliance on cloud services. What if you could keep your existing hardware but replace the voice assistant with a local, open-source alternative? A new open hardware drop-in board offers exactly that: for just $85, you can convert your first-generation Google Home Mini into a device powered by Home Assistant. This article explores how this board works, what it costs, and who might benefit from such a modification.

What Is the Google Home Mini (1st Gen)?

Released in 2017, the Google Home Mini was a compact, affordable smart speaker designed primarily to interact with Google Assistant. Users could ask questions, set reminders, control smart home devices, play music, and more—all through voice commands. However, every voice query was sent to Google’s servers for processing, raising privacy concerns for some users. Despite its age, the hardware—a small speaker, microphone array, and Wi-Fi connectivity—remains quite capable, making it a candidate for repurposing.

The Cloud Dependency Dilemma

Many smart home enthusiasts prefer local control to avoid internet outages, reduce latency, and protect privacy. Google Assistant, like most mainstream voice assistants, relies on cloud processing. This means your voice data leaves your home to be interpreted on remote servers. For those committed to a privacy-first smart home, this is a dealbreaker. But discarding functional hardware is wasteful and expensive. An alternative is to modify the device to run a local voice assistant like Home Assistant’s built-in voice pipeline or a compatible service.

Introducing the $85 Drop-In Board

The open hardware board (designed by a community developer and available through platforms like Tindie or GitHub) is a drop-in replacement for the original Google Home Mini’s mainboard. It measures exactly the same size and fits into the existing enclosure without any cutting or soldering. The board is powered by an Espressif ESP32 or similar microcontroller, pre-flashed with firmware that integrates seamlessly with Home Assistant. It uses the original speaker, microphones, and power supply, but replaces the Google chipset with an open-source alternative. The board also includes a USB-C port for easy firmware updates.

How It Works

Once installed, the Google Home Mini no longer communicates with Google servers. Instead, it connects directly to your Home Assistant installation over your local network. Voice commands are processed locally (or via a compatible cloud service of your choice, such as Whisper or Rhasspy). The board exposes a simple API that Home Assistant can use to trigger automations, play text-to-speech, or control devices. The result is a fully local smart speaker that responds to your voice without sending data outside your home.

Firmware and Compatibility

The board ships with a default firmware that supports basic voice commands and integration with Home Assistant. Users can also flash custom firmware using the ESP-IDF or Arduino framework. The board is compatible with Home Assistant 2023.x and later and works with the official Assist feature. For advanced users, the board supports MQTT and HTTP endpoints for custom automation.

Installation Process

Installing the board is straightforward and does not require advanced electronic skills, though basic familiarity with opening electronic devices is recommended. Steps:

1. Unplug the Google Home Mini and remove the rubber base using a plastic spudger.
2. Gently disconnect the ribbon cables for the speaker, microphone, and power button from the original board.
3. Remove the original board and replace it with the drop-in board, securing it with the provided standoffs.
4. Reconnect all cables (the board is keyed to prevent mistakes).
5. Close the device, plug it in, and configure it via the Home Assistant web interface.

Complete installation guides and video tutorials are available on the developer’s GitHub repository.

Benefits and Considerations

Pros

• Privacy: All voice processing can happen locally, no data leaves your home.
• Cost-effective: At $85, it’s cheaper than buying a new local-first smart speaker.
• Open source: Full schematics and source code are available for inspection and modification.
• Easy installation: No soldering or permanent modification to the case.

Cons

• Limited to 1st-gen hardware: Only works with the 2017 model; newer Google Home Mini versions are not supported.
• Requires Home Assistant: You need an existing Home Assistant setup (Raspberry Pi, NUC, etc.).
• No Google services: You lose access to Google’s built-in music streaming, YouTube, and other integrations.
• Audio quality: The original speaker is small and not designed for high-fidelity music; it’s mainly for voice responses.

Who Is This For?

This board is ideal for smart home enthusiasts who already run Home Assistant and want to expand voice control without adding more cloud-dependent devices. It’s also perfect for privacy-conscious users who already own a Google Home Mini and want to repurpose it. If you are comfortable with basic tinkering and have a Home Assistant server up and running, this is an excellent weekend project.

Conclusion

The $85 drop-in board breathes new life into an old Google Home Mini, transforming it into a privacy-respecting, locally controlled voice assistant. It showcases the power of open hardware and the flexibility of the Home Assistant ecosystem. While not for everyone—especially those who heavily rely on Google services—it’s a compelling option for those who prioritize control and privacy. If you have an old 1st-gen Google Home Mini gathering dust, consider giving it a second life with this clever board.