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.
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?
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!
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?
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.
If you've been on the fence, now's the time. The board will remain available after the campaign through Crowd Supply, but campaign backing is how you get it first.
Also worth mentioning - the final board revision adds an MPR121 capacitive touch controller (replacing the ESP32-S3's built-in touch due to a confirmed, permanently closed IDF bug), plus two extra test points: an alternative +5V/GND power input (if you don't want to reuse the original power daughterboard) and a mic mute bypass.
GitHub - iMike78/home-mini-v1-drop-in-pcb: Replacement PCB for the Google Home mini v1 · GitHub
