EncManaged_pi

OpenCPN plugin that automatically syncs NOAA ENC (Electronic Navigational Charts) from the NOAA ENC Product Catalog.

Self-contained — no external tools required. All sync logic is implemented in C++ inside the plugin.

Features

• Scheduled background sync (hourly / every 6h / every 12h / daily / weekly)
• Manual "Sync Now" from preferences
• Atomic chart updates — safe to interrupt; existing charts never removed until replacement is ready
• Resume-safe — state saved per chart; re-run picks up where it left off
• Parallel downloads (configurable worker count)
• Writes chartdldr_pi.dat for OpenCPN's Chart Downloader plugin compatibility

Requirements

• OpenCPN 5.2+ (plugin API 1.18)
• CMake 3.18+
• libcurl
• wxWidgets (headers only — OpenCPN provides the library at runtime)
• C++ compiler with C++17 support

All third-party source dependencies (tinyxml2, nlohmann/json, OpenCPN plugin header) are vendored in the repository.

Installing from a Release

Pre-built tarballs for macOS (arm64) and Linux (x86_64, aarch64) are published on the Releases page.

1. Download the tarball for your platform
2. In OpenCPN: Options → Plugins → Import plugin...
3. Select the downloaded tarball
4. Restart OpenCPN and enable the plugin

The imported plugin supports Reinstall from within OpenCPN's plugin manager.

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Build & Install

Option A — Nix (recommended)

Nix provides a fully reproducible dev shell with all dependencies pinned.

# Install Nix with flakes enabled, then:
direnv allow        # auto-activates dev shell via .envrc
# or manually: nix develop

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
cmake --install build

Option B — Homebrew (macOS)

brew install cmake pkg-config curl wxwidgets

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
cmake --install build

Option C — apt (Debian / Ubuntu)

sudo apt install cmake pkg-config libcurl4-openssl-dev libwxgtk3.2-dev build-essential

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
sudo cmake --install build

For older Ubuntu (< 23.04) replace libwxgtk3.2-dev with libwxgtk3.0-gtk3-dev.

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cmake --install copies the plugin library and registers it with OpenCPN by writing three files to OpenCPN's plugin config directory:

File	Purpose
plugins/install_data/imports/encmanaged.xml	Marks plugin as imported so OpenCPN shows it in the Plugins list
plugins/install_data/encmanaged.files	File manifest (used by OpenCPN for uninstall tracking)
plugins/install_data/encmanaged.version	Installed version; prevents a spurious "update available" button

Without these files, OpenCPN silently drops the plugin from its internal array when the Plugins tab is opened and it never appears in the list.

Screenshots

Setup

1. Restart OpenCPN after install
2. Open Options → Plugins — EncManaged appears in the list
3. Check Enabled and click Apply (OpenCPN may ask to restart)
4. Click the wrench icon to open preferences
5. Set chart directory (default: ~/Documents/Charts/MANAGED_ENC/US)
6. Enable auto-refresh and choose sync interval
7. Click Sync Now for an immediate sync

Add the chart directory to OpenCPN: Options → Charts → Add directory.

After each sync, scan for new charts via Tools → Charts → Scan for new/updated charts.

File layout

<chart_path>/
├── .sync-state.json      # per-chart edition/update tracking
├── chartdldr_pi.dat      # OpenCPN Chart Downloader plugin state
└── {CELLNAME}/
    ├── {CELLNAME}.000    # S-57 chart data
    └── {CELLNAME}A.TXT   # chart info

Platform support

Platform	Status	Notes
macOS	Primary	Tested on arm64 (Apple Silicon)
Linux	Supported	x86_64 and aarch64 (Raspberry Pi 5)
Windows	Not scoped	OpenCPN/wxWidgets Windows build not tested