G102 Controller

Unofficial Android app that controls the RGB lighting of Logitech G102/G203 LIGHTSYNC mice directly over USB — no PC, no G HUB, no root.

Not affiliated with, endorsed by, sponsored by, or supported by Logitech.

What it does

• RGB on/off
• Custom solid colors (presets or any hex value)
• Brightness (native for cycle-class effects; RGB scaling for solid)
• Effects: Solid, Cycle, Wave (direction), Breathe, Blend, Zones
• Three-zone colors
• Phone and tablet layouts, portrait and landscape
• USB diagnostics with copy/share
• Fully local: zero permissions, no network, no analytics

Lighting commands are sent only when you press a button — never on startup, rotation, or reconnect.

Compatibility

Status	Device	Notes
✅ Tested	Logitech G102 LIGHTSYNC (046D:C092)	Samsung Galaxy Tab A9+, Android 16, USB OTG
🧪 Expected	Logitech G203 LIGHTSYNC	Same USB identity and command set; untested

See COMPATIBILITY.md for the full matrix and how to report your hardware.

Installation

1. Download the APK from Releases
2. Allow installs from your browser when Android asks
3. Connect the mouse via a USB OTG adapter
4. Open the app and tap GRANT USB ACCESS

Requires Android 7.0+ with USB Host. No root, no PC.

Usage

1. RGB OFF turns the lighting off; RGB ON restores your saved setup
2. Pick a color and APPLY COLOR
3. Pick an effect, adjust speed or direction, APPLY

Lighting is runtime control: power-cycling the mouse restores its onboard configuration. The app never writes the mouse's onboard memory.

How it works

The app talks HID++ to the mouse over Android's USB Host API using HID SET_REPORT control transfers. Packet builders are pure Kotlin with no Android imports, unit-tested against reference vectors. See ARCHITECTURE.md and PROTOCOL.md.

Building

./gradlew assembleDebug        # debug APK
./gradlew testDebugUnitTest    # unit tests
./gradlew lintDebug            # lint

JDK 17, Android SDK 35. GitHub Actions builds every push.

Troubleshooting

See TROUBLESHOOTING.md.

Contributing

See CONTRIBUTING.md. Hardware compatibility reports are especially welcome — include VID/PID from the app's diagnostics.

License

MIT — LICENSE. Third-party notices: THIRD_PARTY_NOTICES.md; licensing rationale: LICENSING.md.