Revive Your Old Google Home Mini: An $85 PCB Brings Local AI Processing

The Silent Speaker: Why Your Google Home Mini Deserves a Second Chance

The Google Home Mini, launched in 2017, was once a ubiquitous smart speaker, given away with subscriptions and promotions. Millions still sit in drawers or quietly gather dust, functional for basic commands but long abandoned by Google's software updates. Its successor, the Nest Mini, has also been discontinued, and whispers of new Gemini-powered speakers hint at an uncertain future for the old guard. But before you toss that first-generation device into e-waste, consider this: a third-party PCB from MiciMike can breathe new life into the hardware, bringing local AI processing and modern smart home integration for just $85.

Revive Your Old Google Home Mini: An $85 PCB Brings Local AI Processing — Source: itsfoss.com

Core Upgrades: What the MiciMike PCB Brings

Rather than replacing the entire speaker, this small board (72 × 70 mm, 4-layer PCB) swaps out the original internals while keeping the familiar shell, speaker, and physical mute button. The result is a device that runs on ESPHome out of the box, ready to serve as a local voice assistant in your Home Assistant setup. Let's dive into the components that make this possible.

Espressif ESP32-S3: The Brains

The main processor is an Espressif ESP32-S3, a dual-core Xtensa LX7 chip clocked at 240 MHz. It brings 8 MB of PSRAM and 16 MB of flash memory, enough to handle Wi-Fi (802.11 b/g/n on 2.4 GHz) and Bluetooth 5.0 LE connectivity. Crucially, the ESP32-S3 runs microWakeWord for wake word detection entirely on-device, meaning no voice data ever leaves your home network. This is a massive privacy gain compared to cloud-dependent original firmware.

XMOS XU316: Audio Processing Specialist

Voice commands are useless if the microphone picks up every fan hum or echo. To tackle audio quality, the board includes an XMOS XU316 chip with 4 MB of its own flash. This dedicated audio processor scrubs noise and echo from the two on-board MEMS microphones (placed in the same positions as the original Home Mini). The result is a clean audio stream for the ESP32 to interpret, whether you're speaking across the room or from the next corner.

Software Integration: Home Assistant, Music, and More

ESPHome comes preinstalled on the MiciMike board, so it integrates seamlessly with Home Assistant's Assist. You can trigger automations, query sensors, or control lights – all via local voice commands. The board also works with Music Assistant and Snapcast for multi-room audio. If you want a cloud LLM as the conversation agent, you can configure that, but the entire system runs perfectly without any internet dependency for core functions.

Hardware Details: Keeping It Simple

The original Google Home Mini's speaker is reused, connected via the included FPC cable. The physical mute button on the bottom of the device retains its hardware-level disconnect, now wired to the new board. Four SK6812 RGB LEDs sit in the same location as the originals, providing status indicators. You can even reference their light patterns for debugging.

Full Technical Specifications

Main processor: ESP32-S3 (dual-core Xtensa LX7, 240 MHz), 8 MB PSRAM, 16 MB flash
Audio processor: XMOS XU316, 4 MB flash
Microphones: 2 × MEMS (same location as Home Mini)
LEDs: 4 × SK6812 RGB
PCB: 4-layer, 72 × 70 mm, HASL lead-free
Connectivity: Wi-Fi 802.11 b/g/n (2.4 GHz), Bluetooth 5.0 LE
License: CERN-OHL-S

With a straightforward installation process (you'll need to open the Home Mini and swap the board), the MiciMike PCB turns a forgotten gadget into a locally-controlled smart speaker. At $85, it's a cost-effective alternative to buying a new device and a win for repairability enthusiasts.

Ready to get started? Review the core upgrades or jump straight to the full specs.

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