Files
ledgrab/server
alexei.dolgolyov 29bdacf69a refactor(processing): dedupe HA/Z2M _swap_color_source via shared helper
HALightTargetProcessor and Z2MLightTargetProcessor used to carry
character-for-character identical _swap_color_source method bodies
(audit finding C5) — only the log prefix differed. Extract the body
into a free function ``swap_color_source(processor, new_kind,
new_color_vs_id, *, log_label)`` in a new ``light_target_helpers``
module. Each processor's _swap_color_source now delegates to the helper
and then clears its per-entity history (``_previous_colors`` /
``_previous_on``) — that bit stays on the processor because it's per-
target state, not colour-source state.

Scope deliberately narrower than the full BaseLightTargetProcessor ABC
the audit gestured at: the 76 read sites for the per-processor colour
state across the two files made a full state-composition refactor too
risky for the live LED control loop. The free-function helper is the
minimum-blast-radius way to delete the duplication while leaving WLED
(which has no value-stream-vs-CSS dispatch) untouched.

The helper standardises both warning messages on HA's original wording
("failed to acquire color VS stream" / "failed to re-acquire CSS
stream") so existing log alerts/grep patterns keep working.

A LightTargetSwapState Protocol under TYPE_CHECKING documents the
expected processor surface; no runtime enforcement (acceptable trade-
off vs a 76-site touchpoint).

Tests: 7 new tests cover the release+acquire ordering, the not-running
no-op path, the manager-error-swallowing behaviour, the empty-id
short-circuit, and the missing-manager (TargetContext(None, None))
fallback. 354 existing storage + API + e2e + processing tests stay
green; ruff clean.
2026-05-22 22:54:14 +03:00
..
2026-05-10 23:57:47 +03:00

LedGrab - Server

High-performance FastAPI server that captures screen content and controls WLED devices for ambient lighting.

Overview

The server component provides:

  • 🎯 Real-time Screen Capture - Multi-monitor support with configurable FPS
  • 🎨 Advanced Processing - Border pixel extraction with color correction
  • 🔧 Flexible Calibration - Map screen edges to any LED layout
  • 🌐 REST API - Complete control via 25+ REST endpoints
  • 💾 Persistent Storage - JSON-based device and configuration management
  • 📊 Metrics & Monitoring - Real-time FPS, status, and performance data

Quick Start

# Start server
docker-compose up -d

# View logs
docker-compose logs -f

# Stop server
docker-compose down

Server runs on: http://localhost:8080

Option 2: Python

# Create virtual environment
python -m venv venv

# Activate
source venv/bin/activate  # Linux/Mac
venv\Scripts\activate      # Windows

# Install dependencies
pip install .

# Set PYTHONPATH
export PYTHONPATH=$(pwd)/src  # Linux/Mac
set PYTHONPATH=%CD%\src       # Windows

# Run server
uvicorn ledgrab.main:app --host 0.0.0.0 --port 8080

Installation

Requirements

  • Python 3.11+ (for Python installation)
  • Docker & Docker Compose (for Docker installation)
  • WLED device on your network

See ../INSTALLATION.md for comprehensive installation guide.

Configuration

Configuration File

Edit config/default_config.yaml:

server:
  host: "0.0.0.0"
  port: 8080
  log_level: "INFO"

processing:
  default_fps: 30        # Target frames per second
  max_fps: 60           # Maximum allowed FPS
  border_width: 10      # Pixels to sample from edge

wled:
  timeout: 5            # Connection timeout (seconds)
  retry_attempts: 3     # Number of retries

storage:
  devices_file: "data/devices.json"

logging:
  format: "json"
  file: "logs/ledgrab.log"

Environment Variables

# Server configuration
export LEDGRAB_SERVER__HOST="0.0.0.0"
export LEDGRAB_SERVER__PORT=8080
export LEDGRAB_SERVER__LOG_LEVEL="INFO"

# Processing configuration
export LEDGRAB_PROCESSING__DEFAULT_FPS=30
export LEDGRAB_PROCESSING__BORDER_WIDTH=10

# WLED configuration
export WLED_WLED__TIMEOUT=5

Usage

WLED Device Setup

Important: Configure your WLED device using the official WLED web interface before connecting it to this controller:

  1. Access WLED Interface: Open http://[wled-ip] in your browser
  2. Configure Device Settings:
    • Set LED count and type
    • Configure brightness, color order, and power limits
    • Set up segments if needed
    • Configure effects and presets

This controller only sends pixel color data - it does not manage WLED settings like brightness, effects, or segments. All WLED device configuration should be done through the official WLED interface.

API Documentation

Quick Example

# 1. Add device
curl -X POST http://localhost:8080/api/v1/devices \
  -H "Content-Type: application/json" \
  -d '{"name":"Living Room","url":"http://192.168.1.100","led_count":150}'

# 2. Start processing
curl -X POST http://localhost:8080/api/v1/devices/{device_id}/start

# 3. Check status
curl http://localhost:8080/api/v1/devices/{device_id}/state

Testing

# Run all tests
pytest

# Run with coverage
pytest --cov=ledgrab --cov-report=html

# Run specific test
pytest tests/test_screen_capture.py -v

Development

Project Structure

src/ledgrab/
├── main.py              # FastAPI application
├── config.py            # Configuration
├── api/                 # API routes
├── core/                # Core functionality
│   ├── screen_capture.py
│   ├── wled_client.py
│   ├── calibration.py
│   └── processor_manager.py
├── storage/             # Data persistence
└── utils/               # Utilities

Code Quality

# Format code
black src/ tests/

# Lint code
ruff check src/ tests/

License

MIT - see ../LICENSE

Support