MiciMike ReV Devices
Audio & Music
Microcontroller Boards
Funding ended on Jun 11, 2026 at 04:59 PM PDT.
MiciMike Home Mini Drop-In Board replaces the original mainboard of a Google Home Mini (1st generation) with a fully open, privacy-respecting alternative — no case modifications, no soldering, no compromises. Just swap the board and your old cloud-dependent device becomes a fully local Home Assistant voice assistant. The board arrives pre-flashed and ready to use — no firmware installation required.
You probably have one sitting in a drawer right now — a Google Home Mini that stopped being useful the moment you decided to take back control of your smart home. It works perfectly fine as a piece of hardware: it has a quality speaker, a compact well-designed enclosure, and microphone positions that work. MiciMike transforms this into your own privacy-respecting and open source voice assistant.
Built around the ESP32-S3 and the XMOS XU316 audio processor — the same combination used in the official Home Assistant Voice Preview Edition — the MiciMike board brings professional-grade audio processing to a device you already own. Wake word detection runs entirely on-device, and everything is powered by the ESPHome ecosystem you already know and trust.
Most smart speakers are always listening — and sending what they hear to someone else’s servers. Even when manufacturers promise privacy, the architecture makes true privacy impossible: audio has to leave your home to be processed.
The MiciMike board gives you the choice. Running on ESPHome with Home Assistant’s local voice pipeline, your voice commands can be processed entirely within your home — no cloud, no vendor account, no subscription. If you prefer to use a cloud-based conversation agent such as ChatGPT or another LLM, that option is available too. Privacy is not enforced, but it is genuinely possible — and that is more than most devices offer.
The hardware mute functionality physically disconnects the microphones — not a software flag, but an actual hardware switch inherited from the original Google Home Mini design. When it’s muted, it’s muted.
The Google Home Mini (1st generation) is one of the most widely distributed smart speakers ever made. Millions were sold, given away, and handed out as promotional gifts. Many of them still work perfectly — they just became less useful over time. Google’s new Gemini voice assistant is rolling out to the Home Mini (1st gen), but only as a limited experience: advanced features like Gemini Live continuous conversation are restricted to newer devices. For many users, the Home Mini has quietly become a second-class device in Google’s ecosystem.
The MiciMike board is a genuine drop-in replacement. The PCB is designed to the exact dimensions of the original board, using the same connector and the same microphone positions. Installation requires no soldering, no 3D printing, no case modifications. The step-by-step guide walks you through the process with photographs at every stage.
The result is a device that looks identical to the original Google Home Mini on the outside, and is completely transformed on the inside.
The MiciMike Home Mini Drop-In Board is fully open hardware, licensed under CERN-OHL-S v2. The firmware is ESPHome — the same open-source firmware that powers the official Home Assistant Voice Preview Edition. Every design file, schematic, and BOM is publicly available on GitHub.
This matters for several reasons. It means you are never dependent on a single vendor for support, updates, or spare parts. It means the community can build on, improve, and adapt the design. It means that if something needs fixing, you can fix it — or someone in the community will.
The CERN-OHL-S v2 license is a strongly reciprocal open hardware license: any derivative work must also be released under the same license. This ensures that improvements to the design stay open and available to everyone.
Audio Processing
Main Processor
Compatibility
Firmware
Hardware
In the Box
| MiciMike Home Mini DiP | HA Voice PE | Satellite1 | Onju Voice | Wyoming Satellite | |
|---|---|---|---|---|---|
| Required additional hardware | Google Home Mini (1st gen) | None | None | Google Nest Mini (2nd gen) | RPi Zero 2W + ReSpeaker HAT + SD + PSU + enclosure |
| Drop-in / no case mod | Repurposes Google Home Mini (1st gen) | Standalone device | Standalone device | Repurposes Google Nest Mini (2nd gen) | Custom build required |
| Dedicated audio chip (XMOS) | XU316 | XU316 | XU316 | None | None |
| ESPHome native | Yes | Yes | Yes | Limited | No |
| Wake word on-device | microWakeWord | microWakeWord | microWakeWord | microWakeWord | (server-side) |
| Open hardware | CERN-OHL-S v2 | Yes | CERN-OHL-S v2 | CC BY-NC 4.0 | No |
| Open firmware | Yes | Yes | Yes | Yes | Yes |
| Built-in speaker | Yes (reuses original) | Yes | Yes (25W amp) | Yes (reuses original) | Optional |
| Form factor | Repurposes existing hardware | Premium standalone | Dev kit (2 boards) | Repurposes existing hardware | Custom / 3D printed |
| Total estimated cost | $85 | $59 | $70 | ~$85 for five assembled boards | ~$75 + assembly time |
Hardware
Firmware
Community & Support
The MiciMike Home Mini Drop-In Board is manufactured by Elecrow, a Crowd Supply manufacturing partner based in Shenzhen, China. Elecrow handles the complete production process: PCB fabrication, component sourcing, PCBA, and programming of both the XMOS XU316 and ESP32-S3 firmware. Boards arrive pre-flashed and ready for installation.
The board has been through four hardware revisions during development. The current revision (v4) is the version listed in this campaign and represents a stable, tested design.
Fulfillment is handled by Crowd Supply and Mouser Electronics. Once manufactured boards arrive at Mouser’s warehouse, orders are shipped directly to backers worldwide through Crowd Supply’s standard fulfillment process.
The initial production batch size will be determined by the campaign funding goal. Estimated lead time from end of campaign to first shipment will be confirmed once the batch quantity is finalized and production is scheduled with Elecrow.
Anytime there is a new product brought to market, there are challenges to be overcome. Through careful planning and foresignt, we have worked to ensure that any obstacles are accounted for to ensure our products are delivered to you on time. Here are some of the preventative steps we’ve taken so far:
Component availability
The XMOS XU316 is the most critical component in the design. For smaller batches of a few hundred units, stock is generally available from distributors. For larger orders in the thousands, lead times may apply. Component availability will be monitored closely and orders placed early to mitigate any delays.
Hardware revision
The current board is v4, the result of four development iterations. While the design is stable and tested, as with any hardware product, unforeseen issues may emerge during full production. Elecrow’s production process includes quality checks, and a production sample will be reviewed before approving the full run.
Firmware maturity
ESPHome’s voice assistant support is actively developed and improving rapidly. Some advanced features may depend on future ESPHome or Home Assistant updates. Core functionality — wake word detection, voice commands, media playback — is stable and well-supported today.
Regulatory certification
CE and UKCA certification for Europe and the UK, and RCM certification for Australia, are currently in progress. Products without the required certification cannot be shipped to customers in those regions. We are working to complete the necessary declarations of conformity before shipment, with guidance from Crowd Supply and Elecrow.
MiciMike Home Mini Drop-In PCB is part of Elecrow Project Aviary
Produced by MiciMike ReV Devices in Bandon, co. Cork, Ireland.
Sold and shipped by Crowd Supply.
Drop-in replacement main board and FPC cable for the Google Home Mini (1st generation). No case modifications required. Enables fully local, privacy-respecting Home Assistant voice assistant functionality via ESP32-S3 (ESPHome) + XMOS XU316 audio processing.
Want to buy this item? Check the current project page for the latest information.
We design and develop open-source, drop-in replacement mainboards that transform discontinued smart speakers into fully local, privacy-focused Home Assistant voice devices.
