scottbez1/smartknob

SmartKnob is a hardware project for building a physical knob whose feel, the clicks, stops, and resistance you feel as you turn it, is controlled entirely in software. Instead of a fixed mechanical mechanism, the knob uses a small brushless motor (the same kind used in camera gimbals) paired with a magnetic position sensor. The motor pushes back against your fingers in real time, which lets the code decide where the detents are, where the endstops live, and how much resistance the knob should give at any moment. The README walks through a more elaborate variant called SmartKnob View, which adds a small round LCD screen mounted inside the knob itself. That version pairs the motor with a 240x240 circular display, an ESP32 microcontroller for the brains, side-firing RGB LEDs around the edge, a USB-C connector for power and programming, an ambient light sensor for automatic brightness, and a strain-gauge setup so the knob can also detect being pressed. The README sketches scenarios where this kind of input shines: a video editor jog wheel where you can physically feel the clip boundaries, a playback-speed wheel that snaps at 1x, 2x, and 4x and springs back to paused, and other tactile interfaces that a normal mouse or touchscreen cannot reproduce. Planned future work mentioned in the README includes wifi support and Home Assistant integration. The author is upfront that this is a do-it-yourself open-source project, not a finished consumer product, building one requires advanced surface-mount soldering and patience for hardware debugging.