TL;DR: DIY home automation is ezpz with nothing more than a stepper motor, an esp32, and a high tolerance for Jank. My rental apartment’s AC unit can only be controlled using these retro-looking analog knob-based controls, mounted right onto the unit. No separate wall-mounted thermostat, no remote control… nothin’ fancy whatsoever. These knobs work… but having to constantly stand up and fiddle with them gets annoying pretty quick. Fortunately, there’s an ‘ol Prilik family saying that goes something like this: “remember son - the hardest problems in life can usually be solved with nothing more than a stepper motor, an esp32, and a dream” 1 And sure enough, after dropping ~$15 on parts, waiting for things to arrive from China, and spending a few hours iterating on the hardware assembly and firmware… I hacked together this beautiful mess: What you’re looking at here is a jerry-rigged esp32-controlled stepper motor , coupled to one of my AC unit’s knobs using a shaft coupler , all affixed to the AC’s back-plane…