canboat

NMEA 2000 decoding, encoding and live-bus access, as a Rust library and a command-line tool. The whole CANboat PGN database — some 600 message definitions, reverse-engineered on the water since 2009 — is compiled in: nothing to load at runtime, and every PGN both decodes and encodes.

The tool

cargo install canboat

installs one binary, canboat, whose subcommands replace the historical scatter of CANboat utilities:

subcommand
`convert`	decode any capture (PLAIN/FAST, Actisense, YDWG-02, iKonvert, `.pcap`, `.nif`, …) to PLAIN, JSON or text; the successor of `analyzer`
`interface`	bridge a live gateway — Actisense NGT-1, Digital Yacht iKonvert, Maretron IPG, Linux SocketCAN — to and from stdout
`server`	one process that reads a device, decodes, applies quirks and serves snapshot / analyzer-JSON / NMEA 0183 / AIS / raw ports over TCP
`tui`	a `top`-like terminal browser for a live bus or a capture
`format-message`	build one frame from `FIELD=VALUE` pairs, for any PGN
`replay`, `n2kd`	pace a capture at wall-clock rhythm; multiplex analyzer JSON to TCP clients

Pre-built binaries for Linux (static musl, x86_64 / aarch64 / armv7), macOS and Windows are on the releases page.

The library

[dependencies]
canboat = { version = "8", default-features = false, features = ["decode"] }

The public API is deliberately small: think in terms of a Frame (a raw PGN on the wire) and a DecodedPgn. Fields are addressed by generated, compile-checked constants — a typo, or a field from the wrong PGN, fails the build instead of erroring at runtime.

use canboat::{Database, EncodeValue, FieldValue, Units};
use canboat::ids::field::wind_data as wd;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let db = Database::embedded(Units::Metric);

    // Encode PGN 130306 "Wind Data": 5.23 m/s at 1.5 rad, apparent wind.
    let frame = db
        .encode("windData")?
        .push(wd::WIND_SPEED, 5.23)?
        .push(wd::WIND_ANGLE, 1.5)?
        .push(wd::REFERENCE, EncodeValue::Lookup("Apparent".into()))?
        .build()?;

    // Decode it back — the read side mirrors the write side.
    let decoded = db.decode(&frame).expect("valid frame decodes");
    match &decoded.field(wd::REFERENCE).unwrap().value {
        FieldValue::Lookup { name, .. } => assert_eq!(*name, Some("Apparent")),
        other => panic!("unexpected: {other:?}"),
    }
    Ok(())
}

Features enable you to choose what you want to do and not pay for (in terms of binary size and dependencies) what you do not need.

feature
`decode`	the baseline: schema, decode, encode, JSON output. No threads, no sockets, no I/O
`io`	readers for capture files, and `bus::open_ngt1` / `open_ikonvert` / `open_socketcan` for a live link
`node`	be a compliant NMEA 2000 node without owning a transport: ISO NAME, address claim, the standard responses
`bridge`	the whole `canboat server` pipeline as a library: `Bridge` owns the bus, hands you a `Receiver<DecodedPgn>`, and optionally re-serves the TCP ports
`nmea0183`, `ais`, `json-input`	output and input formatter sub-features
`cli`	the binary (the default; library users turn it off)

The full API reference is on docs.rs.

Where the schema comes from

The tables are generated from the YAML database in the CANboat repository by its keel tool — the same source the C analyzer and canboat.json are generated from — and are committed into this crate, so the published crate is self-contained. To change a PGN, edit the database upstream by forking the canboat github repository and running keel, followed by a PR back upstream, not this crate.

canboat 8.2.1

canboat

The tool

The library

Where the schema comes from

License