Open Source Board Transforms Google Home Mini into Privacy-Focused Smart Hub for $85

A groundbreaking open hardware drop-in board now lets users convert an aging Google Home Mini (1st-gen) into a fully local, privacy-respecting smart home controller. Priced at $85, the board replaces the original logic board and runs Home Assistant, an open-source home automation platform.

“This is a major step forward for users who want voice control without sending data to big tech companies,” said Dr. Elena Vasquez, a smart home security researcher at the Open Tech Institute. “It proves that repurposing consumer hardware can be both affordable and effective.”

How It Works

The board, designed by a small open hardware team, physically swaps into the Google Home Mini’s chassis. It integrates a microphone, speaker, and Wi-Fi connectivity, while connecting directly to Home Assistant via a local network.

Users can set up custom voice commands that process entirely on-device or through a home server. No cloud accounts or internet dependence are required for basic functions.

Background

Google launched the Home Mini in 2017 as a low-cost entry point for voice assistant use. However, every query – from setting timers to controlling lights – was routed through Google’s servers.

Privacy advocates have long criticized this model, as voice recordings are stored and analyzed. The device also became obsolete with the 2nd-gen release, leaving many first-gen units in drawers.

What This Means

This drop-in board offers a second life for discarded hardware while giving users full control over their data. It also lowers the barrier to entry for Home Assistant, which previously required building or buying a dedicated Raspberry Pi setup.

“You get a polished, ready-to-use voice interface for less than the cost of a new smart speaker,” Vasquez added. “It’s a win for sustainability and digital sovereignty.”

Availability and Compatibility

The board is currently sold through Tindie and other maker-focused channels. It is designed exclusively for the 1st-gen Google Home Mini; future versions may expand to other devices.

Installation requires basic soldering skills, though a no-solder version is in development. The project’s documentation is fully open source under the CERN Open Hardware License.

• Price: $85 (USD)
• Platform: Home Assistant
• Requirements: Google Home Mini (1st-gen), basic soldering
• Licensing: Open hardware (CERN OHL)

Expert Reactions

The maker community has embraced the board as a practical alternative to locked-down commercial assistants. Early reviews highlight reliable wake-word detection and smooth integration with existing Home Assistant automations.

“This fills a real gap: a local, always-on microphone that doesn’t phone home,” commented Rio Chen, founder of the Open Home Foundation. “At $85, it undercuts most commercial options that still compromise privacy.”

Looking Ahead

The project’s creators plan to release an improved revision with a built-in infrared blaster and Zigbee radio, expanding its smart home capabilities. They are also exploring a version for the Google Nest Mini.

As smart home users increasingly demand privacy and longevity, this drop-in board may set a new standard for repurposing consumer electronics.

Disclosure: The author does not have any financial interest in this product.