MiciMike Home Mini Drop-In Board – ESP32-S3 + XMOS XU316 replacement mainboard for Google Home Mini (Gen 1)

Configuration Voice Assistant
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Hi everyone,

I wanted to share a project I’ve been working on for a while — a drop-in replacement mainboard for the Google Home Mini (1st gen) that turns it into a fully local Home Assistant voice assistant.

The idea is simple: the original Google Home Mini has a decent speaker and a compact, well-designed enclosure — all perfectly usable. The only thing holding it back is the proprietary mainboard. This project replaces just that.

What’s inside the replacement board:

  • ESP32-S3 — handles ESPHome, Wi-Fi, and HA integration
  • XMOS XU316 — dedicated audio DSP for mic processing (noise suppression, echo cancellation)
  • Fits directly into the original enclosure, reusing the case, speaker, power daughterboard, and touch surface
  • Firmware comes pre-flashed; configure it like any other ESPHome device

No cloud. No Google account. No subscription. Just a local voice assistant that runs entirely within your Home Assistant instance.

The hardware is open (CERN-OHL-S v2) and the firmware is open (ESPHome). Everything is on GitHub: :point_right: GitHub - iMike78/home-mini-v1-drop-in-pcb: Replacement PCB for the Google Home mini v1 · GitHub

If you’re curious about the campaign or want to get your hands on one, it’s live on Crowd Supply: :point_right: MiciMike Home Mini Drop-In PCB | Crowd Supply

Happy to answer any questions about the hardware, the firmware, or the build process.

Here are the articles published so far about the project:
Your Google Home Mini, Rebuilt for Privacy
MiciMike board converts Google Home Mini into local Home Assistant voice device
100% Local, 0% Cloud: A Privacy-First Brain for Your Google Home Mini

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Hey, I got recommended an article mentioning the project yesterday and instantly got interested, this sounds amazing!
I was about to order a Home Mini 1st Gen to jump into it when I decided to search for a 2nd Gen alternative.
I ended finding another thread with people discussing a project for a PCB replacement for the 2nd Gen in which I saw you posted a work-in-progress board for the 2nd Gen.

So, my question is, is there still a plan for a 2nd gen version? Was there any specific reason to “launch” the 1st Gen first?

Thanks for the amazing work!

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Thanks, glad you found it!

Yes, a 2nd Gen version is planned and will be the next campaign. Interestingly, I actually started working on the 2nd Gen first, but the 1st Gen ended up being completed sooner. No particular reason — it just worked out that way, and in hindsight the chronological order makes sense anyway.

So if you can hold off on hunting down a 1st Gen Mini, it might be worth keeping an eye on what’s coming next!

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Hi @iMike78,

Quick question about both boards, will both still use the same power connectors (micro USB and barrel jack)?
I was hoping if they could somehow be converted to usb-c.

I saw a USB-c on one of the pictures from the gen 2 PCB on GitHub, but I assume that is for dev and not power in the original enclosure?

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Hi.
Yes, you are right, the USB-C port is for dev purpose only, my current plan is, the 2nd gen will have a separate 7-14V power input to give the option for an alternative use scenario. Of course that way will be more of a DIY option as you will have to use the MUTE tp as well.

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FYI, you can find out more about iMike78's two ongoing projects in their respecitve GitHub repo:

and

Note that those repos each also have their own discussions section for deeper questions, see:

as well as

For reference, that other forum thread you refer to is my "open-letter" request to the community:

That is a broader discussion about PCB alternatives for all Google Nest line of of speakers:

Join in all of those for discussions about different replacemnent PCB boards for Google devices!