gateway

package
v1.1.0 Latest Latest
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 Go to latest Published: Aug 20, 2026 License: MIT Imports: 19 Imported by: 0

Documentation

Overview

Package gateway parses the wire formats spoken by NMEA 2000 network gateways: the Yacht Devices RAW ASCII line protocol and the Actisense binary stream protocol.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func EncodeSend 

func EncodeSend(m N2KMessage) ([]byte, error)

EncodeSend renders an assembled N2K message as an Actisense transmit command (0x94). The payload layout is priority (1), PGN (3, little-endian), destination (1), data length (1), data. There is no source-address byte: the gateway transmits under its own claimed bus address, so m.Source is not carried on the wire. The gateway also performs fast-packet fragmentation itself, which is why sends are whole messages rather than CAN frames.

func EncodeStartup 

func EncodeStartup() []byte

EncodeStartup renders the historical unacknowledged mode-2 command. Mode 2 disables the receive PGN list only; the transmit list remains active. New session adapters use an acknowledged BEM handshake instead.

func FormatYDRawTX 

func FormatYDRawTX(frame can.Frame) []byte

FormatYDRawTX renders a CAN frame as a Yacht Devices RAW transmit line. Application-to-gateway lines carry no time or direction field — just the 29-bit identifier and the data bytes, CRLF-terminated: 

19F51323 01 02<CR><LF>

Once the gateway transmits the frame onto the bus it echoes the line back with a timestamp and direction T, which ParseYDRaw accepts like any other frame. Filtered or malformed lines get no echo.

func ParseYDRaw 

func ParseYDRaw(line string) (can.Frame, bool)

ParseYDRaw parses one line of the Yacht Devices RAW protocol (YDWG-02 and compatible gateways), e.g. 

17:33:21.107 R 09F11201 01 5C 3D FF 7F FF 7F FC

The direction field is R (received from the bus) or T (transmitted to the bus); both carry frames. Returns ok=false for service messages, blank lines, and anything else that does not carry a CAN data frame.

func ParseYDRawObservation added in v1.0.0 

func ParseYDRawObservation(line string) (raw.Observation, bool)

ParseYDRawObservation preserves the gateway's relative timestamp and receive/transmit direction in addition to the CAN frame.

func ReadActisense added in v0.2.0 

func ReadActisense(r io.Reader, handler func(can.Frame)) error

ReadActisense reassembles Actisense messages from r and emits CAN frames. Message-level D0 records and gateway diagnostics require the Observation Interface and are intentionally omitted by this compatibility helper.

func ReadActisenseObservations added in v1.0.0 

func ReadActisenseObservations(r io.Reader, handler func(raw.Observation)) error

ReadActisenseObservations decodes all supported BDTP/BST datagrams until EOF.

func ReadYDRaw added in v0.2.0 

func ReadYDRaw(r io.Reader, handler func(can.Frame)) error

ReadYDRaw delivers Yacht Devices RAW lines from r as CAN frames until EOF or a read error. It is the single reader for the RAW protocol, shared by the TCP bus and the read-only network sources.

func ReadYDRawObservations added in v1.0.0 

func ReadYDRawObservations(r io.Reader, handler func(raw.Observation)) error

ReadYDRawObservations preserves direction and gateway-relative timestamps.

func Reframe 

func Reframe(m N2KMessage, seq uint8) ([]can.Frame, error)

Reframe converts an assembled N2K message back into wire CAN frames: a single frame for non-fast PGNs up to 8 bytes, fast-packet frames for fast PGNs up to 223 bytes. PGNs absent from the metadata tables are framed by size (fast iff the payload exceeds 8 bytes). seq is the fast-packet sequence ID (0-7).

func ReframeEmitter 

func ReframeEmitter(handler func(can.Frame)) func(N2KMessage)

ReframeEmitter adapts a CAN-frame handler into an assembled-message consumer: each message is re-framed into wire CAN frames (rotating the fast-packet sequence ID per message) and fed to the handler. Messages that cannot be re-framed are dropped.

Types

type ActisenseModeSetupError added in v1.1.0 

type ActisenseModeSetupError struct {
	RequestedMode actisense.OperatingMode
	Err           error
}

ActisenseModeSetupError reports a failed acknowledged operating-mode setup. The public package translates it into ActisenseModeError.

func (*ActisenseModeSetupError) Error added in v1.1.0 

func (e *ActisenseModeSetupError) Error() string

func (*ActisenseModeSetupError) Unwrap added in v1.1.0 

func (e *ActisenseModeSetupError) Unwrap() error

type ActisenseObservationAdapter added in v1.1.0 

type ActisenseObservationAdapter struct {
	// contains filtered or unexported fields
}

ActisenseObservationAdapter exposes the transport-neutral BST-to-Observation Adapter to capture readers without exporting protocol state from this internal package.

func NewActisenseObservationAdapter added in v1.1.0 

func NewActisenseObservationAdapter() *ActisenseObservationAdapter

func (*ActisenseObservationAdapter) HandleDatagram added in v1.1.0 

func (a *ActisenseObservationAdapter) HandleDatagram(datagram actisense.Datagram, handler func(raw.Observation))

func (*ActisenseObservationAdapter) HandleDecodeError added in v1.1.0 

func (a *ActisenseObservationAdapter) HandleDecodeError(err actisense.DecodeError, handler func(raw.Observation))

type ActisenseRawSerialBus added in v1.1.0 

type ActisenseRawSerialBus struct {
	// contains filtered or unexported fields
}

ActisenseRawSerialBus is a source-authoritative BST-95 raw CAN Bus over a direct 115200 8N1 serial connection.

func NewActisenseRawSerialBus added in v1.1.0 

func NewActisenseRawSerialBus(log *slog.Logger, port string) *ActisenseRawSerialBus

func (*ActisenseRawSerialBus) Close added in v1.1.0 

func (b *ActisenseRawSerialBus) Close() error

func (*ActisenseRawSerialBus) Ready added in v1.1.0 

func (b *ActisenseRawSerialBus) Ready() <-chan struct{}

func (*ActisenseRawSerialBus) Run added in v1.1.0 

func (b *ActisenseRawSerialBus) Run(ctx context.Context, handler func(can.Frame)) error

func (*ActisenseRawSerialBus) RunObservations added in v1.1.0 

func (b *ActisenseRawSerialBus) RunObservations(ctx context.Context, handler func(raw.Observation)) error

func (*ActisenseRawSerialBus) WriteFrame added in v1.1.0 

func (b *ActisenseRawSerialBus) WriteFrame(frame can.Frame) error

type ActisenseRawTCPBus added in v1.1.0 

type ActisenseRawTCPBus struct {
	// contains filtered or unexported fields
}

ActisenseRawTCPBus is a source-authoritative BST-95 raw CAN Bus.

func NewActisenseRawTCPBus added in v1.1.0 

func NewActisenseRawTCPBus(log *slog.Logger, addr string, reconnect *ReconnectPolicy) *ActisenseRawTCPBus

func (*ActisenseRawTCPBus) Close added in v1.1.0 

func (b *ActisenseRawTCPBus) Close() error

func (*ActisenseRawTCPBus) Ready added in v1.1.0 

func (b *ActisenseRawTCPBus) Ready() <-chan struct{}

func (*ActisenseRawTCPBus) Run added in v1.1.0 

func (b *ActisenseRawTCPBus) Run(ctx context.Context, handler func(can.Frame)) error

func (*ActisenseRawTCPBus) RunObservations added in v1.1.0 

func (b *ActisenseRawTCPBus) RunObservations(ctx context.Context, handler func(raw.Observation)) error

func (*ActisenseRawTCPBus) SetConnectionObserver added in v1.1.0 

func (b *ActisenseRawTCPBus) SetConnectionObserver(observer func(bool, uint64))

func (*ActisenseRawTCPBus) WriteFrame added in v1.1.0 

func (b *ActisenseRawTCPBus) WriteFrame(frame can.Frame) error

type ActisenseReader 

type ActisenseReader struct {
	// contains filtered or unexported fields
}

ActisenseReader is an incremental decoder for the Actisense binary stream protocol. It tolerates arbitrary buffer boundaries: bytes are fed as they arrive and complete messages are emitted as they are recognized.

func NewActisenseReader 

func NewActisenseReader() *ActisenseReader

NewActisenseReader returns a reader ready to consume stream bytes.

func (*ActisenseReader) Feed 

func (r *ActisenseReader) Feed(buf []byte, emit func(N2KMessage))

Feed consumes raw stream bytes; emit is called once per complete, checksum-valid N2K message (command 0x93). Garbage between messages is skipped and messages that fail their checksum are dropped silently.

type ActisenseSerialBus added in v1.1.0 

type ActisenseSerialBus struct {
	// contains filtered or unexported fields
}

ActisenseSerialBus is the gateway-owned BST-93/94 message session over a direct 115200 8N1 serial connection.

func NewActisenseSerialBus added in v1.1.0 

func NewActisenseSerialBus(log *slog.Logger, port string) *ActisenseSerialBus

func (*ActisenseSerialBus) Close added in v1.1.0 

func (b *ActisenseSerialBus) Close() error

func (*ActisenseSerialBus) Ready added in v1.1.0 

func (b *ActisenseSerialBus) Ready() <-chan struct{}

func (*ActisenseSerialBus) Run added in v1.1.0 

func (b *ActisenseSerialBus) Run(ctx context.Context, handler func(can.Frame)) error

func (*ActisenseSerialBus) RunObservations added in v1.1.0 

func (b *ActisenseSerialBus) RunObservations(ctx context.Context, handler func(raw.Observation)) error

func (*ActisenseSerialBus) WriteFrame added in v1.1.0 

func (b *ActisenseSerialBus) WriteFrame(frame can.Frame) error

func (*ActisenseSerialBus) WriteMessage added in v1.1.0 

func (b *ActisenseSerialBus) WriteMessage(pgnNumber uint32, priority, _ uint8, destination uint8, payload []byte) error

type ActisenseTCPBus 

type ActisenseTCPBus struct {
	// contains filtered or unexported fields
}

ActisenseTCPBus is the v1-compatible, gateway-owned BST-93/94 message session. It is retained for compatibility; raw CAN mode is the authoritative Client Bus.

func NewActisenseTCPBus 

func NewActisenseTCPBus(log *slog.Logger, addr string, reconnect *ReconnectPolicy) *ActisenseTCPBus

func (*ActisenseTCPBus) Close 

func (b *ActisenseTCPBus) Close() error

func (*ActisenseTCPBus) Ready added in v1.1.0 

func (b *ActisenseTCPBus) Ready() <-chan struct{}

func (*ActisenseTCPBus) Run 

func (b *ActisenseTCPBus) Run(ctx context.Context, handler func(can.Frame)) error

func (*ActisenseTCPBus) RunObservations added in v1.0.0 

func (b *ActisenseTCPBus) RunObservations(ctx context.Context, handler func(raw.Observation)) error

func (*ActisenseTCPBus) SetConnectionObserver added in v1.0.0 

func (b *ActisenseTCPBus) SetConnectionObserver(observer func(bool, uint64))

func (*ActisenseTCPBus) WriteFrame 

func (b *ActisenseTCPBus) WriteFrame(frame can.Frame) error

func (*ActisenseTCPBus) WriteMessage 

func (b *ActisenseTCPBus) WriteMessage(pgnNumber uint32, priority, _ uint8, destination uint8, payload []byte) error

type Backoff added in v0.2.0 

type Backoff struct {
	// contains filtered or unexported fields
}

Backoff is a re-armable exponential backoff sequencer. It is not safe for concurrent use; a single reconnect loop owns one Backoff.

func NewBackoff added in v0.2.0 

func NewBackoff(policy ReconnectPolicy) *Backoff

NewBackoff returns a Backoff seeded from policy, substituting defaults for any non-positive field.

func (*Backoff) Reset added in v0.2.0 

func (b *Backoff) Reset()

Reset returns the sequencer to its initial delay, so the next Wait sleeps for InitialBackoff again. Call it after a connection is successfully established so a brief reconnect does not inherit a long prior backoff.

func (*Backoff) Wait added in v0.2.0 

func (b *Backoff) Wait(ctx context.Context) bool

Wait sleeps for the next backoff interval, doubling it up to MaxBackoff on each successive call, and returns true. It returns false immediately if ctx is cancelled before the interval elapses.

type N2KMessage 

type N2KMessage = actisense.Message

N2KMessage is one NMEA 2000 message carried by an Actisense stream. Data is the assembled PGN payload (fast-packet PGNs arrive already assembled).

type ReconnectPolicy added in v0.2.0 

type ReconnectPolicy struct {
	// InitialBackoff is the delay before the first reconnect attempt after a
	// drop, and the delay restored after any successful connection.
	InitialBackoff time.Duration
	// MaxBackoff caps the exponentially growing delay between attempts while a
	// connection cannot be re-established.
	MaxBackoff time.Duration
}

ReconnectPolicy configures automatic re-dialing of a dropped gateway connection. A nil *ReconnectPolicy means reconnection is disabled: a dropped connection ends the read loop (the historical behavior).

type YDRawTCPBus 

type YDRawTCPBus struct {
	// contains filtered or unexported fields
}

YDRawTCPBus is a read/write bus over a TCP gateway speaking the Yacht Devices RAW line protocol (YDWG-02 RAW server mode and compatibles). RAW mode is frame-level in both directions, so the full client stack — address claiming included — works exactly as it does on CAN hardware. The gateway echoes transmitted frames back with direction T, so the client also observes its own traffic.

func NewYDRawTCPBus 

func NewYDRawTCPBus(log *slog.Logger, addr string, reconnect *ReconnectPolicy) *YDRawTCPBus

NewYDRawTCPBus returns an unconnected bus; Run dials. A non-nil reconnect policy makes Run re-dial dropped connections.

func (*YDRawTCPBus) Close 

func (b *YDRawTCPBus) Close() error

Close releases the connection.

func (*YDRawTCPBus) Run 

func (b *YDRawTCPBus) Run(ctx context.Context, handler func(can.Frame)) error

Run connects and delivers incoming frames to handler until ctx is cancelled or (without a reconnect policy) the connection fails.

func (*YDRawTCPBus) RunObservations added in v1.0.0 

func (b *YDRawTCPBus) RunObservations(ctx context.Context, handler func(raw.Observation)) error

RunObservations preserves gateway transport context.

func (*YDRawTCPBus) SetConnectionObserver added in v1.0.0 

func (b *YDRawTCPBus) SetConnectionObserver(observer func(bool, uint64))

SetConnectionObserver installs reconnect lifecycle observation for Client.

func (*YDRawTCPBus) WriteFrame 

func (b *YDRawTCPBus) WriteFrame(frame can.Frame) error

WriteFrame transmits one CAN frame as a RAW line.

Source Files

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