# Aniker GPS

A Rust library for parsing NMEA GPS sentences.

## Features

- Parse GGA sentences to extract latitude, longitude, altitude, and more
- Support for different units of measurement (meters, feet)
- Comprehensive error handling with custom error types
- Simple and efficient API

## Usage

Add this to your `Cargo.toml`:

```toml
[dependencies]
aniker-gps = "0.1.0"
```

### Example

```rust
use aniker_gps::{parse_gga, GpsError};

fn main() {
    // Example NMEA GGA sentence
    let mut gga_example = "$GPGGA,210230,3855.4487,N,09446.0071,W,1,07,1.1,370.5,M,-29.5,M,,*7A".to_string();

    // Parse the GGA sentence and handle the result
    match parse_gga(&mut gga_example) {
        Ok(position) => {
            println!("Latitude: {}", position.lat);
            println!("Longitude: {}", position.long);
            println!("Altitude: {} {}", position.alt, position.altitude_unit);
            println!("Geoid Separation: {} {}", position.geoid_separation, position.geoid_unit);
        }
        Err(e) => {
            println!("Error parsing GGA sentence:");
            match e {
                GpsError::InvalidMessageType => println!("  Invalid message type, expected GGA"),
                GpsError::InvalidLength => println!("  Invalid GGA sentence length"),
                GpsError::ParseError(msg) => println!("  Parse error: {}", msg),
                GpsError::Other(msg) => println!("  Other error: {}", msg),
            }
        }
    }
}
```

## Error Handling

The library provides a custom `GpsError` enum for error handling:

```rust
pub enum GpsError {
    /// Invalid message type (not GGA)
    InvalidMessageType,
    /// Invalid sentence length
    InvalidLength,
    /// Error parsing a numeric field
    ParseError(String),
    /// Other errors
    Other(String),
}
```

This allows for more detailed error handling and better error messages.

## GGA Sentence Format

The GGA sentence contains the following fields:

- Sentence type (checked for "GGA")
- Current time (UTC)
- Latitude (in DDMM.MMM format)
- Latitude compass direction (N/S)
- Longitude (in DDDMM.MMM format)
- Longitude compass direction (E/W)
- Fix type (0 for no fix, 1 for GPS, 2 for DGPS)
- Number of satellites used for fix
- Horizontal dilution of precision
- Altitude above mean sea level
- Altitude units (M for meters, F for feet)
- Height of mean sea level above WGS-84 earth ellipsoid
- Units of the above geoid separation (M for meters, F for feet)
- Time since last differential correction (if available)
- Differential station ID (if available)
- Checksum validation value

## License

This project is licensed under either of

 * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or https://www.apache.org/licenses/LICENSE-2.0)
 * MIT license ([LICENSE-MIT](LICENSE-MIT) or https://opensource.org/licenses/MIT)

at your option.