When HA sets a color via turn_on, also update the source's fallback_color
to match. This way when the api_input timeout fires (default 5s), the
stream reverts to the same color instead of black. turn_off resets
fallback to [0,0,0].
Added coordinator.update_source() for PUT /color-strip-sources/{id}.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
LED Grab
Ambient lighting system that captures screen content and drives LED strips in real time. Supports WLED, Adalight, AmbileD, and DDP devices with audio-reactive effects, pattern generation, and automated profile switching.
What It Does
The server captures pixels from a screen (or Android device via ADB), extracts border colors, applies post-processing filters, and streams the result to LED strips at up to 60 fps. A built-in web dashboard provides device management, calibration, live LED preview, and real-time metrics — no external UI required.
A Home Assistant integration exposes devices as entities for smart home automation.
Features
Screen Capture
- Multi-monitor support with per-target display selection
- 6 capture engine backends — MSS (cross-platform), DXCam, BetterCam, Windows Graphics Capture (Windows), Scrcpy (Android via ADB), Camera/Webcam (OpenCV)
- Configurable capture regions, FPS, and border width
- Capture templates for reusable configurations
LED Device Support
- WLED (HTTP/UDP) with mDNS auto-discovery
- Adalight (serial) — Arduino-compatible LED controllers
- AmbileD (serial)
- DDP (Distributed Display Protocol, UDP)
- OpenRGB — PC peripherals (keyboard, mouse, RAM, fans, LED strips)
- Serial port auto-detection and baud rate configuration
Color Processing
- Post-processing filter pipeline: brightness, gamma, saturation, color correction, auto-crop, frame interpolation, pixelation, flip
- Reusable post-processing templates
- Color strip sources: audio-reactive, pattern generator, composite layering, audio-to-color mapping
- Pattern templates with customizable effects
Audio Integration
- Multichannel audio capture from any system device (input or loopback)
- WASAPI engine on Windows, Sounddevice (PortAudio) engine on Linux/macOS
- Per-channel mono extraction
- Audio-reactive color strip sources driven by frequency analysis
Automation
- Profile engine with condition-based switching (time of day, active window, etc.)
- Dynamic brightness value sources (schedule-based, scene-aware)
- Key Colors (KC) targets with live WebSocket color streaming
Dashboard
- Web UI at
http://localhost:8080— no installation needed on the client side - Progressive Web App (PWA) — installable on phones and tablets with offline caching
- Responsive mobile layout with bottom tab navigation
- Device management with auto-discovery wizard
- Visual calibration editor with overlay preview
- Live LED strip preview via WebSocket
- Real-time FPS, latency, and uptime charts
- Localized in English, Russian, and Chinese
Home Assistant Integration
- HACS-compatible custom component
- Light, switch, sensor, and number entities per device
- Real-time metrics via data coordinator
- WebSocket-based live LED preview in HA
Requirements
- Python 3.11+ (or Docker)
- A supported LED device on the local network or connected via USB
- Windows, Linux, or macOS — all core features work cross-platform
Platform Notes
| Feature | Windows | Linux / macOS |
|---|---|---|
| Screen capture | DXCam, BetterCam, WGC, MSS | MSS |
| Webcam capture | OpenCV (DirectShow) | OpenCV (V4L2) |
| Audio capture | WASAPI, Sounddevice | Sounddevice (PulseAudio/PipeWire) |
| GPU monitoring | NVIDIA (pynvml) | NVIDIA (pynvml) |
| Android capture | Scrcpy (ADB) | Scrcpy (ADB) |
| Monitor names | Friendly names (WMI) | Generic ("Display 0") |
| Profile conditions | Process/window detection | Not yet implemented |
Quick Start
git clone https://github.com/yourusername/wled-screen-controller.git
cd wled-screen-controller/server
# Option A: Docker (recommended)
docker-compose up -d
# Option B: Python
python -m venv venv
source venv/bin/activate # Linux/Mac
# venv\Scripts\activate # Windows
pip install .
export PYTHONPATH=$(pwd)/src # Linux/Mac
# set PYTHONPATH=%CD%\src # Windows
uvicorn wled_controller.main:app --host 0.0.0.0 --port 8080
Open http://localhost:8080 to access the dashboard. The default API key for development is development-key-change-in-production.
See INSTALLATION.md for the full installation guide, including Docker manual builds and Home Assistant setup.
Architecture
wled-screen-controller/
├── server/ # Python FastAPI backend
│ ├── src/wled_controller/
│ │ ├── main.py # Application entry point
│ │ ├── config.py # YAML + env var configuration
│ │ ├── api/
│ │ │ ├── routes/ # REST + WebSocket endpoints
│ │ │ └── schemas/ # Pydantic request/response models
│ │ ├── core/
│ │ │ ├── capture/ # Screen capture, calibration, pixel processing
│ │ │ ├── capture_engines/ # MSS, DXCam, BetterCam, WGC, Scrcpy, Camera backends
│ │ │ ├── devices/ # WLED, Adalight, AmbileD, DDP, OpenRGB clients
│ │ │ ├── audio/ # Audio capture engines
│ │ │ ├── filters/ # Post-processing filter pipeline
│ │ │ ├── processing/ # Stream orchestration and target processors
│ │ │ └── profiles/ # Condition-based profile automation
│ │ ├── storage/ # JSON-based persistence layer
│ │ ├── static/ # Web dashboard (vanilla JS, CSS, HTML)
│ │ │ ├── js/core/ # API client, state, i18n, modals, events
│ │ │ ├── js/features/ # Feature modules (devices, streams, targets, etc.)
│ │ │ ├── css/ # Stylesheets
│ │ │ └── locales/ # en.json, ru.json, zh.json
│ │ └── utils/ # Logging, monitor detection
│ ├── config/ # default_config.yaml
│ ├── tests/ # pytest suite
│ ├── Dockerfile
│ └── docker-compose.yml
├── custom_components/ # Home Assistant integration (HACS)
│ └── wled_screen_controller/
├── docs/
│ ├── API.md # REST API reference
│ └── CALIBRATION.md # LED calibration guide
├── INSTALLATION.md
└── LICENSE # MIT
Configuration
Edit server/config/default_config.yaml or use environment variables with the LED_GRAB_ prefix:
server:
host: "0.0.0.0"
port: 8080
log_level: "INFO"
auth:
api_keys:
dev: "development-key-change-in-production"
storage:
devices_file: "data/devices.json"
templates_file: "data/capture_templates.json"
logging:
format: "json"
file: "logs/wled_controller.log"
max_size_mb: 100
Environment variable override example: LED_GRAB_SERVER__PORT=9090.
API
The server exposes a REST API (with Swagger docs at /docs) covering:
- Devices — CRUD, discovery, validation, state, metrics
- Capture Templates — Screen capture configurations
- Picture Sources — Screen capture stream definitions
- Picture Targets — LED target management, start/stop processing
- Post-Processing Templates — Filter pipeline configurations
- Color Strip Sources — Audio, pattern, composite, mapped sources
- Audio Sources — Multichannel and mono audio device configuration
- Pattern Templates — Effect pattern definitions
- Value Sources — Dynamic brightness/value providers
- Key Colors Targets — KC targets with WebSocket live color stream
- Profiles — Condition-based automation profiles
All endpoints require API key authentication via X-API-Key header or ?token= query parameter.
See docs/API.md for the full reference.
Calibration
The calibration system maps screen border pixels to physical LED positions. Configure layout direction, start position, and per-edge segments through the web dashboard or API.
See docs/CALIBRATION.md for a step-by-step guide.
Home Assistant
Install via HACS (add as a custom repository) or manually copy custom_components/wled_screen_controller/ into your HA config directory. The integration creates light, switch, sensor, and number entities for each configured device.
See INSTALLATION.md for detailed setup instructions.
Development
cd server
# Install with dev dependencies
pip install -e ".[dev]"
# Run tests
pytest
# Format and lint
black src/ tests/
ruff check src/ tests/
Optional extras:
pip install -e ".[perf]" # High-performance capture engines (Windows)
pip install -e ".[camera]" # Webcam capture via OpenCV
License
MIT — see LICENSE.