kinavis-nmea2000

NMEA 2000 parameter groups from CAN frames to the kinavis-kernel value types.

NMEA 2000 devices send numbered parameter groups — fixed little-endian layouts in one 8-byte frame or, as a fast packet, up to 32 frames. From frames delivered by the bus interface, this crate parses the 29-bit identifier (PGN, source), reassembles fast packets and decodes the group into kernel types: Position, Speed, TrueCourse, Distance, Instant. "Not available" is None, never the raw all-ones value.

• Position rapid update (129025); COG/SOG rapid update (129026); GNSS position data (129029), with a kernel GnssFix.
• Vessel heading (127250) with reference, deviation and variation; water depth (128267).
• AIS position reports from an AIS receiver: class A (129038), class B (129039).
• Other PGNs: Message::Unsupported with the PGN and raw payload.
• No allocation: fixed-capacity payload buffer; assembler with fixed slots and a timeout.
• No panics: every failure is an Nmea2000Error.

The CAN controller, driver and address claim are the caller's.

use kinavis_nmea2000::{Assembler, CanId, Frame, Message, Pgn};
use kinavis_kernel::{Instant, Utc};

let mut assembler = Assembler::new();
let now = Instant::<Utc>::from_unix_seconds(1_789_000_000);

// Water depth from address 9: 12.34 m below the transducer, which is
// 1.5 m above the keel.
let id = CanId::from_parts(3, Pgn::WATER_DEPTH, 255, 9);
let frame = Frame::new(id, &[0x01, 0xD2, 0x04, 0x00, 0x00, 0x24, 0xFA, 0x0A])?;

let Some(payload) = assembler.push(&frame, now)? else { panic!("in frames") };
let Message::WaterDepth(depth) = Message::decode(&payload)? else { panic!("not a depth") };

assert_eq!(payload.source(), 9);
assert_eq!(format!("{:.2}", depth.depth.unwrap().metres()), "12.34");
assert_eq!(format!("{:.2}", depth.depth_from_reference().unwrap().metres()), "10.84");
# Ok::<(), Box<dyn std::error::Error>>(())

Feature flags

• std (default) — standard library maths in the kernel.
• libm — for no_std targets: --no-default-features --features libm.
• serde — serialisation of the messages.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.