MaYaRa Radar Playback Plugin for SignalK

A SignalK plugin for playing back .mrr radar recordings through the SignalK Radar API.

Prerequisites

This plugin requires SignalK server with the Radar API enabled. The Radar API is not yet in upstream SignalK — it is available via:

• PR SignalK/signalk-server#2357 — Radar API refactored

Until that PR is merged, use a SignalK server build that includes the Radar API (e.g. from the radar_api branch).

What This Plugin Does

This plugin allows you to play pre-recorded radar data (.mrr files) through SignalK's Radar API. During playback, the recording appears as a virtual radar that any SignalK radar consumer can connect to and display.

Use cases:

• Test and develop SignalK radar display applications without live radar hardware
• Demo radar functionality at exhibitions or presentations
• Debug radar rendering code with consistent, repeatable data
• Share interesting radar captures with other developers

Installation

Install from the SignalK App Store:

1. Open your SignalK server web interface
2. Go to Appstore > Available
3. Search for "MaYaRa Radar Playback"
4. Click Install
5. Restart SignalK when prompted

Getting Started

1. Access the Playback Interface

After installation, navigate to:

http://your-signalk-server:3000/@marineyachtradar/signalk-playback-plugin/playback.html

Or find it in SignalK's Webapps menu.

2. Upload a Recording

You can upload .mrr or .mrr.gz files:

• Drag and drop a file onto the upload zone
• Or click the upload zone to browse for a file

Recordings are stored on the SignalK server and persist across restarts.

3. Load and Play

1. Select a recording from the list
2. Click Load to prepare it for playback
3. Click Play to start playback
4. Use Pause and Stop as needed
5. Enable Loop to repeat the recording continuously

4. View the Radar

Click View Radar to open the radar display. This shows the playback radar using the built-in viewer.

Viewing with Other Clients

During playback, the recording registers as a virtual radar in SignalK. The radar ID follows the pattern playback-{filename}.

Any application that implements the SignalK Radar API can display the playback:

• The radar appears at /signalk/v2/api/vessels/self/radars/playback-{filename}
• Spoke data streams via SignalK's binary WebSocket at /signalk/v2/api/vessels/self/radars/{id}/stream

Obtaining Recording Files

Recording files (.mrr) are created by mayara-server when connected to a live radar:

1. Run mayara-server with a radar connected
2. Open the recordings page at http://localhost:6502/recordings.html
3. Select a radar and click Start Recording
4. Click Stop Recording when done
5. Download the recording as .mrr.gz (compressed)
6. Upload to this SignalK plugin

File Format

• .mrr - MaYaRa Radar Recording (uncompressed)
• .mrr.gz - Gzip-compressed recording (~95% smaller for transfer)

Both formats are supported for upload. Files are stored uncompressed on the server for fast playback.

Development

Building

The GUI is sourced from mayara-server's web/gui/ directory (expected as a sibling checkout at ../mayara-server/).

npm install
npm run build

To specify a different GUI source path:

node build.js --gui-path /path/to/mayara-server/web/gui

Scripts

• npm run format — prettier + eslint --fix
• npm run lint — eslint check
• npm run build — compile TypeScript + copy GUI
• npm run test — run tests (vitest)
• npm run build:all — lint + build + test

Related Projects

• mayara-server - Standalone radar server (creates recordings, provides GUI)
• signalk-server#2357 - Radar API for SignalK server

License

MIT License - See LICENSE for details.