Open firmware that rescues discontinued Nest thermostats from e-waste.
Google wound down software support for the second-generation Nest Learning Thermostat, quietly turning a beautifully-built piece of hardware into a slow march toward the landfill. Tiny Whale Nest OS is an effort to take that hardware back — a small, open Linux system that replaces the locked stock firmware and turns an abandoned thermostat into a hackable little display-and-sensor computer you actually own.
Under the dial is a real little computer: a single-core ARM chip, 64 MB of memory, and 256 MB of flash storage, driving a round 320×320 display, Wi-Fi, and a handful of sensors.
By modern standards that is tiny — and that is exactly the challenge. There is no room for a bloated operating system, so every piece has to be lean and deliberate. Nothing comes along for the ride unless it earns its place.
The first rule of this project is that no thermostat gets bricked. Instead of overwriting the original firmware, the new system boots entirely in memory and leaves the stock software untouched on the device. If anything misbehaves, a power cycle brings the original firmware straight back.
The chip also has an unkillable recovery mode baked in at the factory, so even a badly-flashed image can be undone over a cable. That safety net is what makes it sane to experiment on hardware you cannot easily replace.
So far: the hardware has been fully mapped, the device’s own software assets have been safely extracted, and the boot path has been validated from start to finish.
The core pieces of the custom system — a minimal Linux userland, networking, remote access, and a small display program — have been built and sized to fit the device’s tight memory budget. A first bootable image has been designed and is ready to assemble.
The next milestone is the first real boot on a physical unit: flashing the new image to a single thermostat, bringing up Wi-Fi and remote access, and lighting up the display under the new system.
After that comes persistence — letting a device hold onto the new OS across reboots — and then repeating the process across the rest of the units. Each step gets documented as it happens.
There are thirteen of these thermostats. Individually they are worth almost nothing; together they are a small fleet of capable, well-made embedded computers that would otherwise end up as e-waste. Giving them a second, open-ended life is the entire point of Tiny Whale.