Example of HID over GATT (Bluetooth Low Energy) Android Application. The application emulates a peripheral BLE device (mouse, keyboard, gamepad, digitizer, and consumer remote) that can be connected to a PC, tablet, or smartphone.
The application consists of 7 full-screen fragments. When more than one device is connected, notifications can be routed to all connected devices simultaneously or toggled individually per host.
- Visual Programming Workspace - drag-and-drop Google Blockly interface to build custom HID macros and automated scripts.
- Rich Block Library - includes blocks for keyboard text/keys, mouse movement, clicks, scrolling, absolute positioning, gamepad sticks/buttons, consumer media controls, delays, loops, and conditional logic.
- Run / Stop Execution - execute programmed scripts in real-time or stop execution with a single tap.
- Save & Load - save macros to internal storage and reload them whenever needed.
- Stash Bar - quick access bar for frequently used blocks.
- Reboot application button - restarts the application and the Bluetooth stack. Useful for refreshing the connection state if any issues occur.
- Clear configs button - deletes saved device pairings and configurations if connection issues occur.
- List of connected devices with toggles - displays connected hosts with individual switches to enable or disable HID notification routing per device.
- Music/player control - buttons for previous track, stop, play/pause, and next track.
- Volume & Brightness - quick adjustments for sound and screen brightness.
- System control - perform system actions like sleep, hibernation, shut down, or restart.
- Application launch - start selected applications such as a calculator or web browser. Supported by specific operating systems.
- Application control - perform actions like "help" or "search" in the currently focused app. Note: these actions are highly application-specific.
- Buttons (1, 2, 3, 4, 5) - emulates standard mouse button clicks (Left, Right, Middle, Button 4, Button 5).
- Touchpad area - move the cursor; double-tap emulates a left-click.
- Horizontal Scroll bar - smooth horizontal panning/scrolling (h-scroll / tilt wheel).
- Volume buttons - the phone's physical volume up/down buttons emulate the vertical mouse scroll wheel.
- Send text - type a phrase and send it to the computer all at once.
- Send character - a dropdown list to select and send a single special character or function key.
- Keyboard shortcuts - dedicated buttons for common actions like Ctrl+C, Ctrl+V, Ctrl+Z, Ctrl+A, and more.
- LED indicators - shows the real-time status of Caps Lock, Num Lock, and Scroll Lock received from the host.
- Keyboard On/Off - enables or disables the software keyboard for direct live typing with smart Caps Lock synchronization.
- Dual Analog Sticks / D-Pad - virtual L-Stick and R-Stick with octagonal bases, double-tap for L3/R3 clicks, and toggles to switch between analog stick or digital D-Pad / button modes.
- Action Buttons (BT0 - BT3) - standard ABXY style action button diamond.
- Shoulder Buttons & Triggers - dedicated LB, RB, LT, and RT buttons.
- Touchpad & System Keys - integrated central touchpad area and MENU / START system buttons.
- Control Toggles - independent toggles for L-Stick, Touchpad, Tab Swiping Lock, and R-Stick.
- Full-Screen Touch Surface - absolute 0–32767 coordinate mapping for touchscreen and digitizer emulation.
- Triple-Tap Exit - triple-tap anywhere inside the touch frame to exit back to standard mouse mode.
- Physical Volume Buttons - physical volume up/down buttons map to primary and secondary touch/click states.
- Real-Time Coordinate Feedback - displays live X/Y absolute coordinates.
- Blockly Visual Automation Engine: Integrated Google Blockly for creating, editing, saving, and executing automated HID macros and scripts (keyboard, mouse, gamepad, consumer controls, delays, loops, and conditional logic) over BLE.
- Full Virtual Gamepad Mode: Added a full-featured gamepad controller with dual analog sticks (L-Stick, R-Stick), D-Pad, L3/R3, ABXY buttons, LB/RB/LT/RT triggers, MENU/START, and an integrated touchpad.
- Absolute Mouse / Digitizer: Introduced a dedicated full-screen absolute positioning mode (0–32767 range) for touchscreen/digitizer emulation with a triple-tap exit gesture.
- Horizontal Mouse Scroll: Added horizontal scrolling/panning (h-scroll) support to the Mouse fragment.
- Per-Device Management: Ability to toggle HID notifications on or off for individual connected Bluetooth hosts directly from the configuration screen.
- HID Battery Reporting: Added Battery System HID report (Report ID 4) and live Battery Level service notifications.
- Smart Keyboard Typing: Smart Caps Lock synchronization with automatic Shift XOR logic and seamless background text input.
- BLE Performance & Modern UI: Implemented low-latency BLE connection requests (
HIGH_PRIORITY) and redesigned the interface with a modern dark theme.
- AI-Driven Modernization: The entire project was refactored and updated in collaboration with Gemini in Android Studio.
- Android 14 Support: Fully updated for the latest security and permission requirements.
- Enhanced Keyboard: Added LED status lights and productivity shortcuts (Ctrl+C, Ctrl+V, etc.).
- Smoother Mouse: Implemented motion merging to prevent cursor "jumping".
- Better Stability: New notification queue system to handle multiple connections reliably.
- Simpler Experience: Removed outdated "basic mode" and refactored the HID descriptor to use smaller, separate reports for better host compatibility.