When your thermostat comes with Linux running on it, that’s not a hack. When it doesn’t, and you get Linux on there yourself, it most definitely is. This is exactly what [cz7asm] has done. In a recent video, he shows the Honeywell thermostat booting Linux and running a wide range of software.
While the hardware inside the thermostat doesn’t afford all the luxuries of a typical modern embedded Linux, it’s got enough room for the basics. The system runs from a 1 MB rootfs in RAM, and has a 2.5 MB kernel image, leaving a spare 12 MB for everything else. With just these meager resources, [cz7asm] shows how the system can use a USB network adapter, connecting to telehack.com for some command-line retro fun, and host a web server, although no browser runs yet. There’s also framebuffer support for displaying graphics and animations, and the usual Linux terminal goodness.
All we’ve seen so far is the video, so we hope [cz7asm] posts the code somewhere, because we’re tired of using our thermostat just to run the AC.
You might remember [cz7asm] from his previous thermostatic triumph: running Doom. Check out the video of the latest thermostat adventure after the break.
Thanks to [Piecutter] for the tip!