Revive Your Old Google Home Mini with an Affordable Upgrade Board

When Google launched the Home Mini in 2017, it quickly became a popular smart speaker, but over time its limited processing and lack of local intelligence made it feel obsolete. Now, a third-party PCB called the MiciMike breathes new life into these devices for just $85. This upgrade replaces the original board with modern chips, enabling local voice processing, full integration with Home Assistant, and enhanced audio. Below, we answer the most pressing questions about this innovative retrofit.

1. What does the MiciMike PCB do for an old Google Home Mini?

This replacement board transforms a first-generation Google Home Mini into a capable 2026-era smart device. It introduces an ESP32-S3 processor for Wi-Fi, Bluetooth, and local wake-word detection via microWakeWord, ensuring all voice data stays on your device. A dedicated XMOS XU316 chip handles audio cleanup, filtering noise and echo from the two on-board MEMS microphones. The result is a speaker that can run Home Assistant's Assist, Music Assistant, and Snapcast locally, with optional cloud LLM integration. All original hardware—the speaker, mute button, and LED indicators—work seamlessly with the new board, giving your aging gadget a second life without e-waste.

2. Which chips power the new board, and what are their roles?

Two main processors drive the upgrade. The Espressif ESP32-S3 acts as the primary brain, running a dual-core Xtensa LX7 at 240 MHz, with 8 MB of PSRAM and 16 MB of flash. It manages Wi-Fi 802.11 b/g/n, Bluetooth 5.0 LE, and wake-word detection—all without sending voice data to the cloud. The XMOS XU316 is dedicated to audio processing, carrying 4 MB of flash. It cleans up incoming sound from two MEMS microphones placed in the original Home Mini locations, removing background noise and echo before any further processing. Together, they provide local intelligence and crisp audio handling that far exceeds the original device.

3. How does this upgrade enhance privacy and local processing?

Privacy is a core design goal. The ESP32-S3 uses microWakeWord for wake-word detection, which runs entirely on the chip—no audio leaves your home network. The XMOS XU316 handles all audio cleanup locally, so no raw microphone data is ever exposed. Additionally, the mute button performs a hardware-level disconnection of the microphones, just like the original Home Mini. This means you can physically cut off audio input when desired. The software stack, based on ESPHome, integrates with Home Assistant's Assist, allowing you to run voice commands without any internet dependency. Optional cloud LLMs can be added for advanced conversations, but the system works fully offline, ensuring your data stays under your control.

4. What software capabilities does the upgraded device offer?

The board comes preinstalled with ESPHome, making it plug-and-play with Home Assistant. Out of the box, you can use Assist for local voice control, Music Assistant for multi-room audio, and Snapcast for synchronized playback. The device can also be configured to use a cloud-based LLM as a conversation agent if desired, but it remains fully functional without any internet connection. This opens up endless possibilities: automation triggers, custom commands, and integration with thousands of smart home devices. The open-source nature means you can modify the firmware to suit your needs, and the 16 MB flash provides plenty of room for custom voice pipelines or sensor data handling.

5. Does the original hardware still work after the upgrade?

Yes, the MiciMike board is designed to reuse all original components. The Home Mini's internal speaker connects via the included FPC cable and continues to deliver audio. The mute button still physically disconnects the microphones at the hardware level, preserving the original safety feature. Four SK6812 RGB LEDs sit in the same positions as the stock LEDs, providing status indicators for power, Wi-Fi connectivity, and voice assistant states. The board itself measures 72 × 70 mm (4-layer, HASL lead-free) and fits snugly inside the existing enclosure. No additional soldering or modification is required—just swap the PCB and reassemble.

6. What are the full technical specifications of the MiciMike PCB?

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

These specs ensure the board can handle modern smart home tasks while remaining energy-efficient and compact.

7. Why is this upgrade timely for old Google Home Mini users?

The first-generation Home Mini has been discontinued, and its successor, the Nest Mini, has also been phased out. Google's current direction points to Gemini-powered smart speakers, but retrofitting existing hardware with the MiciMike board offers a cost-effective, environmentally friendly alternative. For $85, you get local processing, advanced audio cleanup, and full compatibility with the popular Home Assistant ecosystem. This upgrade addresses the device's original lack of customizability and local intelligence, turning a dated speaker into a powerful IoT hub. As smart home enthusiasts seek more privacy and flexibility, this PCB provides a compelling, no-e-waste solution that keeps reliable hardware out of landfills.

8. How easy is it to install the MiciMike board?

Installation is straightforward and requires no soldering. Simply open the original Google Home Mini enclosure, remove the old PCB, disconnect the existing ribbon cables, and replace it with the MiciMike board. The included FPC cable connects the speaker. The two MEMS microphones and four SK6812 LEDs align with the original mounting points. After reassembly, power up the device and connect it to your Wi-Fi via the ESPHome interface. The entire process takes about 10–15 minutes for someone comfortable with basic electronics. Detailed guides are available from the creator, and because the board uses standard connectors, you can always revert to the original if needed. It's an easy win for anyone wanting to modernize their smart speaker.