The MiciMike Home Mini Drop-In PCB is an open-source replacement mainboard designed to convert a 1st Gen Google Home Mini into a fully local, privacy-focused voice assistant running Home Assistant Voice. Built around an ESP32-S3 MCU and an XMOS XU316 audio processor, it removes cloud dependencies without any case modifications or soldering.
The board offers on-device wake word detection, echo cancellation, and noise suppression via two MEMS microphones, and comes pre-flashed with ESPHome for easy Home Assistant integration. The PCBA fully supports local voice processing, optional cloud LLM integration, media playback, and Snapcast. It’s released as open hardware under the CERN-OHL-S v2 license, with complete design files available, making it suitable for privacy-focused smart-home automation, DIY voice assistants, and hardware-reuse projects.
MiciMike Home Mini Drop-In PCB specifications:
- Compatibility – Google Home Mini 1st generation
- Wireless MCU – Espressif Systems ESP32-S3
- CPU – Dual-core Xtensa LX7 microcontroller @ up to 240 MHz
- System Memory – 8MB PSRAM
- Storage – 16MB flash
- Wireless – 2.4 GHz WiFi 4, and Bluetooth 5.0 LE
- Audio
- XMOS XU316 dedicated audio processor featuring Echo Cancellation (AEC) and noise suppression
- 2x on-board MEMS microphones (aligned to the original Google Home Mini positions)
- Custom FPC connector to reuse the original internal speaker
- Misc – Native support for the original hardware mute switch (physically disconnects the microphones)
- Dimensions – 72 × 70 mm, 4-layer PCB (exact footprint of the original mainboard)
On the software side, the board ships with pre-flashed ESPHome firmware and integrates with the Home Assistant Voice Assistant (Assist) pipeline. It also supports Music Assistant and standard media playback. The hardware design is fully open-source under the CERN-OHL-S v2 license, with schematics, BOM, and PCB design files publicly available on GitHub, where you’ll also find a detailed step-by-step installation guide.
Previously, we saw Waveshare introduce the ESP32-S3-AUDIO-Board, an open-source speaker platform based on the ESP32-S3. A project even more closely related to the MiciMike is the Onju Voice v2, which provides a drop-in PCB for the Google Nest Mini (2nd gen) using the same ESP32-S3. It’s not available, but you can order the PCB and make it yourself.
The device is designed by MiciMike ReV Devices in Ireland, and the campaign has already surpassed its $8,000 funding goal. The MiciMike Home Mini Drop-In PCB is available on CrowdSupply for $85, and ships with the required JS05B-16P-050-4-8 FPC cable. Shipping is free within the US and $12 worldwide, with deliveries expected to begin around October 1, 2026.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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