gnss.js


A JavaScript module for GNSS device connections, NMEA parsing, and NTRIP client functionality.

Features

- Device Connectivity: Connect to GNSS receivers via Web Bluetooth or Web Serial APIs
- NMEA Parsing: Parse standard NMEA sentences (GGA, GSA, GSV, RMC, GST, VTG)
- NTRIP Client: Connect to NTRIP casters for RTK correction data with multiple connection modes
- RTK Support: Forward correction data to connected devices
- Event-Based API: Simple, event-driven architecture for real-time data handling
- Browser Support: Works in modern browsers with no server dependencies

Installation

$3

``bash


Using npm

npm install gnss.js

Using yarn

yarn add gnss.js

Using CDN with unpkg

import GnssModule from 'https://unpkg.com/gnss.js@latest/dist/gnss.esm.js';

Using CDN with jsDelivr

import GnssModule from 'https://cdn.jsdelivr.net/gh/BrandonLewis/gnss.js@cdn-dist/dist/gnss.esm.js';
`

$3

#### Using unpkg

`html








`

#### Using jsDelivr (GitHub)

`html











`

Usage

$3

`javascript
import { GnssModule } from 'gnss.js';

// Create a new GNSS module instance
const gnss = new GnssModule();

// Connect to a GNSS device using the best available method
gnss.connectDevice().then(() => {
console.log('Connected to GNSS device');
});

// Listen for position updates
gnss.on('position', (position) => {
console.log('Position update:', position);
// Example position object:
// {
// latitude: 37.7749,
// longitude: -122.4194,
// altitude: 15.2,
// quality: 2,
// satellites: 9,
// hdop: 0.9,
// timestamp: Date
// }
});
`

$3

`javascript
// Connect specifically via Bluetooth
gnss.connectBluetooth().then((success) => {
if (success) {
console.log('Connected via Bluetooth');
} else {
console.error('Failed to connect via Bluetooth');
}
});
`

$3

`javascript
// Connect specifically via Serial port
gnss.connectSerial().then((success) => {
if (success) {
console.log('Connected via Serial port');
} else {
console.error('Failed to connect via Serial port');
}
});
`

$3

`javascript
// Connect to NTRIP service
gnss.connectNtrip({
host: 'rtk2go.com',
port: 2101,
mountpoint: 'YOUR_MOUNTPOINT',
username: 'user', // Optional
password: 'pass', // Optional
sendGga: true, // Send position to caster (required by some services)
connectionMode: 'auto' // auto, direct, proxy, or websocket
}).then((success) => {
if (success) {
console.log('Connected to NTRIP service');
} else {
console.error('Failed to connect to NTRIP service');
}
});

// Listen for RTCM correction data
gnss.on('ntrip:rtcm', (rtcmData) => {
console.log('Received RTCM data:', rtcmData.data.byteLength, 'bytes');
});
`

$3

`javascript
// Connection events
gnss.on('connection:connected', (info) => {
console.log('Device connected via:', info.method);
});

gnss.on('connection:disconnected', () => {
console.log('Device disconnected');
});

gnss.on('connection:error', (error) => {
console.error('Connection error:', error.message);
});

// NTRIP events
gnss.on('ntrip:connected', (info) => {
console.log('NTRIP connected to:', info.casterHost, info.mountpoint);
});

gnss.on('ntrip:disconnected', () => {
console.log('NTRIP disconnected');
});

// Satellite data
gnss.on('satellites', (satellites) => {
console.log('Satellite count:', satellites.length);
});
`

Browser Compatibility

- Chrome 78+ (Desktop & Android)
- Edge 79+
- Opera 65+
- Samsung Internet 12.0+

Features Requiring Secure Context (HTTPS):
- Web Bluetooth API
- Web Serial API

API Documentation

Detailed API documentation is available at:
- GitHub Pages: https://brandonlewis.github.io/gnss.js
- CDN Documentation: https://cdn.jsdelivr.net/gh/BrandonLewis/gnss.js@cdn-dist/docs/index.html

Examples

Check out the examples directory for complete usage examples, including:

- Basic usage example
- RTK positioning with NTRIP
- Satellite tracking
- Custom UI components

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature`)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.