# GNSS Reader

A Rust-based GNSS (Global Navigation Satellite System) data parser that reads GPS location data from serial devices and converts NMEA sentences into structured, usable location information.

## Features

- **NMEA Sentence Parsing**: Supports GPGGA and GPRMC sentence formats
- **Live GPS Reading**: Real-time data streaming from USB GPS devices
- **Demo Mode**: Built-in demonstration with sample GPS data
- **Cross-Platform**: Works on macOS, Linux, and Windows
- **Structured Output**: Converts raw NMEA data into organized LocationData structures
- **Comprehensive Testing**: Includes extensive test coverage for various GPS scenarios

## Requirements

- Rust 2024 edition or later
- USB GPS device (tested with Stratux GPYes 2.0 u-blox 8)
- Serial port access permissions

## Installation

1. Clone the repository:
   ```bash
   git clone <repository-url>
   cd gpyes-stream
   ```

2. Build the project:
   ```bash
   cargo build --release
   ```

3. Run the application:
   ```bash
   cargo run
   ```

## Usage

The application automatically detects and connects to your GPS device. On startup, it will:

1. Attempt to connect to the GPS device via serial port
2. Parse incoming NMEA sentences (GPGGA and GPRMC formats)
3. Display structured location data including:
   - Latitude and Longitude coordinates
   - Altitude information
   - GPS fix quality and satellite count
   - Speed and course data
   - UTC timestamp

### Demo Mode

To run the application with sample data without a physical GPS device:

```bash
cargo run -- --demo
```

## Supported Hardware

### Tested Devices
- **Stratux GPYes 2.0 u-blox 8 USB GPS Unit** (~$20)
  - Amazon: https://www.amazon.com/Stratux-GPYes-2-0-u-blox-unit/dp/B0716BK5NT
  - Device paths on macOS: `/dev/tty.usbmodem2101` or `/dev/cu.usbmodem2101`

### Compatibility
The application should work with any USB GPS device that outputs standard NMEA sentences via serial communication.

## NMEA Sentence Support

Currently supports the following NMEA sentence types:
- **GPGGA**: Global Positioning System Fix Data
- **GPRMC**: Recommended Minimum Course
- **GNGGA**: GNSS Fix Data (multi-constellation)
- **GNRMC**: GNSS Recommended Minimum Course

## Development

### Running Tests

```bash
cargo test
```

### Building for Release

```bash
cargo build --release
```

The compiled binary will be available in `target/release/gnss-reader`.

## Contributing

1. Fork the repository
2. Create a 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 open source. Please refer to the LICENSE file for details.

## Troubleshooting

### Device Not Found
- Ensure your GPS device is properly connected
- Check device permissions (you may need to add your user to the `dialout` group on Linux)
- Verify the device path matches your system configuration

### No GPS Signal
- Ensure you have a clear view of the sky
- Wait for the GPS device to acquire satellite lock (may take several minutes on first use)
- Check that your GPS device is functioning properly