OmniScroll (also commonly searched as Omni Scroll) is an open-source, custom haptic rotary dial and computer input controller built around a freely spinning steel ball bearing and an MX8650 optical mouse sensor. It connects to any PC or Mac as a standard USB HID device with zero drivers or companion software required. Configure haptic detents, modes, RGB calibration, and flick gestures directly from any Chromium browser (Chrome, Edge, Brave, Opera) over the same USB cable using the Web Serial API.
Plug in your OmniScroll device via USB, then open the zero-install control panel:
👉 roufsweb.github.io/OmniScroll
No drivers, companion apps, or background processes required. Runs 100% in-browser over the Web Serial API.
- Zero-Contact Optical Sensing: An MX8650 optical sensor tracks the microscopic surface texture of an industrial steel ball bearing. No mechanical encoder contacts, zero friction wear, and limitless rotational lifespan.
- Native High-Resolution Smooth Scrolling: Implements Microsoft & USB-IF compliant Generic Desktop Usage
0x48(Resolution Multiplier) for fluid, sub-pixel continuous scrolling on Windows and macOS. - Apple-Grade LRA Haptic Detents: An iPhone 6 Linear Resonant Actuator (LRA) driven by a PAM8403 amplifier produces crisp, virtual tactile clicks with tunable frequency, duration, and sharpness.
- TinyOL On-Device Gesture Engine: Adaptive prototype recognition detects rapid ballistic flick gestures (back/forward navigation, tab switching, undo/redo) and dynamically adapts to your personal ergonomics without flash wear.
- Touch & Spin Gated Modifier: Hold the top capacitive disk while rotating to trigger secondary modifier actions (horizontal pan, universal zoom, 4x turbo scroll).
- 8 Workflow Modes: Seamlessly switch between dedicated modes with customized detent feel and RGB LED backlighting.
- Full NVS Persistence: All settings, calibrations, and learned gesture centroids persist directly in ESP32 flash across reboots.
A freely spinning ball bearing acts as the dial. An MX8650 optical mouse sensor sits directly beneath it, reading the surface texture of the bearing as it rotates. This replaces a traditional mechanical rotary encoder entirely — no physical contacts, no wear, and no fixed step resolution.
The "clicks" you feel are not mechanical. An LRA (Linear Resonant Actuator) driven by a PAM8403 amplifier fires a precise tone burst on each virtual detent. Frequency, duration, and intensity are all tunable from the configurator.
The dial operates in configurable modes. Double-tap the top touch zone or perform a configured flick gesture to cycle between active modes.
| Mode | Action | Default LED Color |
|---|---|---|
| Scroll | High-resolution vertical page scroll | Blue |
| Volume | System volume control (with detents) | Green |
| Timeline | Frame-by-frame arrow keys (scrubbing) | Pink |
| Zoom | Ctrl+Scroll — universal zoom in any app | Amber |
| Horizontal Scroll | Side-scroll axis / Pan | Teal |
| Brightness | Display brightness keys | Yellow |
| Tabbing | Ctrl+Tab — cycle browser & app tabs | Violet |
| Undo / Redo | Ctrl+Z / Ctrl+Shift+Z | Red |
All 8 modes are individually configurable. Enable only the ones you use. Colors, step thresholds, invert directions, and haptic detent profiles are saved per mode.
| Component | Part | Notes |
|---|---|---|
| Microcontroller | Lolin ESP32-S2 Mini | Native USB OTG, hardware touch peripheral, LEDC PWM |
| Encoder | MX8650 Optical Sensor | Reads bearing surface via 2-wire serial protocol |
| Haptic Motor | iPhone 6 LRA | Driven by PAM8403 audio amplifier |
| Indicator | Analog 5050 RGB LED | Software white-balanced via PWM hardware calibration |
| Touch Input | ESP32-S2 capacitive touch (GPIO 12) | Hardware-filtered, double-tap, long-press, & touch-hold |
Full schematic, pin mapping, and electrical notes are documented in HARDWARE.md.
All settings are stored in the ESP32's NVS flash and survive power cycles:
- Haptic Detent Profile — Choose from Click, Thud, Tick, Soft, or Off. Set independently per mode.
- RGB Color Palette — Full HSB color wheel with hardware white-balance PWM calibration.
- Sensor Resolution — 400 / 800 / 1200 / 1600 CPI.
- Touch Sensitivity Slider — Continuous 0% to 100% threshold calibration for your hand.
- LED Brightness & Standby — Master dimmer (0–100%) and organic MagSafe amber breathing when host is asleep.
- Flick Gestures & Single Tap — Configurable ballistic actions (Forward / Back navigation, Play/Pause, Next/Prev Mode, Single Tap on dial cap).
- Direction Invert — Reverse rotation direction per mode.
Requires the Arduino IDE with the ESP32 board package installed (v3.x+).
Board Settings:
| Setting | Value |
|---|---|
| Board | Lolin S2 Mini |
| USB CDC On Boot | Disabled (CDCOnBoot=dis_cdc) |
| Partition Scheme | Huge APP |
Flash Procedure:
- Hold the
BOOTbutton on the board. - Press and release
RST. - Release
BOOT(enters Download Mode). - Flash directly from the Arduino IDE or via
arduino-cli.
OmniScroll (also searched as Omni Scroll or Omni-Scroll) is an open-source DIY haptic computer rotary dial and precision optical scroll wheel controller engineered around a freely spinning steel ball bearing and an MX8650 optical mouse sensor, powered by an ESP32-S2 microcontroller. It functions as a native USB HID peripheral without requiring any drivers.
Simply connect the device to your computer via USB, open roufsweb.github.io/OmniScroll in Chrome or Edge, and click Connect Device. The Web Serial API handles all communication directly inside the browser without installing any companion software or background services.
Instead of using traditional notched mechanical encoders that suffer from wear, contact chatter, and fixed click notches, OmniScroll places an MX8650 optical mouse sensor directly beneath the outer race of an industrial steel ball bearing. As the bearing spins freely, the optical sensor tracks surface micro-textures at ~520 counts per 360-degree revolution (0.6923 degrees per count) with limitless rotational life and zero friction.
No. OmniScroll operates as a standard USB HID input device on Windows, macOS, Linux, and ChromeOS. Configuration is handled 100% in-browser over the Web Serial API via the official web control panel with zero drivers or background software needed.
OmniScroll features ballistic Flick Forward and Flick Backward gestures, a Touch & Spin hold-to-scroll modifier, and Single Tap on the dial cap. Supported actions include Browser Back/Forward, Play/Pause, Media Previous/Next, Volume Up/Down, Tab switching, Virtual Desktop navigation, Undo/Redo, and direct mode switching.
OmniScroll features an on-device machine learning recognizer (TinyOL) running in SRAM that measures kinematic phase-energy and normalized Mahalanobis distance. It separates ballistic flick recoil from deliberate scrolling in under 2 microseconds and adapts to individual hand ergonomics without flash wear.