alt Hacker NewsStill working on: an enclosure-compatible open-source version of the 2nd gen Nest thermostat. It reuses the enclosure, encoder ring, display, and mounts of the Nest but replaces the "thinking" part with an open-source PCB that can interact with Home Assistant.
- The encoder ring which works like an LED mouse, but in reverse: Fully reverse-engineered and on its own demo PCB
- The faceplate PCB, which does the actual control of the thermostat wires, has been laid out, but the first version missed a really-obvious problem involving the behavior on power-on with certain of the GPIO pins from the ESP32, so I've got rev 3 on order from the PCB manufacturer.
Nest Thermostats of the 1st and 2nd generation will no longer be supported by Google starting October 25, 2025. You will still be able to access temperature, mode, schedules, and settings directly on the thermostat – and existing schedules should continue to work uninterrupted. However, these thermostats will no longer receive software or security updates, will not have any Nest app or Home app controls, and Google will end support for other connected features like Home/Away Assist. It has been pretty-badly supported in Home Assistant for over a year anyway, missing important connected features.
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I really like the nest encoder/button feel, so I was considering trying to hack mine into a becoming desktop volume control/button... but probably lacking the skills to not make a mess of it. Would love to see how you interface with the existing hardware!
Currently reading Tony Fadell's book, sounds interesting.
Sounds very cool! Also interested in how to follow progress. Is it using ESPHome?
Is this project online anywhere yet that I can watch for it to be ready?
Clever.
Any ideas on how to source 2nd gen Nests? I just checked ebay and my local craigslist; nadda.
Do recyclers accept requests? Like pulling all the Nest units from the waste stream?
Wow! Useful work, if that’s true about them planning to remotely nerf everyone’s product.
Yet another example of why not to buy a product that needs to be tethered to its manufacturer to work. Good luck. I’d be willing to beta test (I’d have to check what rev mine is)
M5 Stack sells a nice controller knob if you don't have a used nest handy
https://shop.m5stack.com/products/m5stack-dial-esp32-s3-smar...
> As a versatile embedded development board, M5Dial integrates the necessary features and sensors for various smart home control applications. It features a 1.28-inch round TFT touchscreen, a rotary encoder, an RFID detection module, an RTC circuit, a buzzer, and under-screen buttons, enabling users to easily implement a wide range of creative projects.
> The main controller of M5Dial is M5StampS3, a micro module based on the ESP32-S3 chip known for its high performance and low power consumption. It supports Wi-Fi, as well as various peripheral interfaces such as SPI, I2C, UART, ADC, and more. M5StampS3 also comes with 8MB of built-in Flash, providing sufficient storage space for users.
I've build a few HA-compatible systems using M5Stack products; mostly the Atom-S3 Lite connected to various sensors and lights.