Documentation
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Overview ¶
Package canbus provides shared NMEA 2000 / CAN bus types and functions importable by both the server internals and client tools.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var Manufacturers = map[uint16]string{}/* 140 elements not displayed */
Manufacturers maps NMEA 2000 manufacturer codes to names.
Functions ¶
func BuildCANID ¶
BuildCANID constructs a 29-bit CAN identifier from a CANHeader. Inverse of ParseCANID: BuildCANID(ParseCANID(x)) == x for valid IDs.
func EncodeName ¶ added in v0.4.0
func EncodeName(f NameEncodeFields) uint64
EncodeName encodes the fields into a 64-bit ISO NAME.
func LookupManufacturer ¶
LookupManufacturer returns a human-readable manufacturer name for common NMEA 2000 codes.
Types ¶
type CANHeader ¶
type CANHeader struct {
Priority uint8
PGN uint32
Source uint8
Destination uint8 // 0xFF for broadcast (PDU2)
}
CANHeader holds the parsed fields from a 29-bit CAN ID.
func ParseCANID ¶
ParseCANID extracts priority, PGN, source address, and destination from a 29-bit CAN identifier per NMEA 2000 / ISO 11783.
CAN ID bit layout (29 bits):
bits 28-26: priority (3 bits) bit 25: reserved (always 0 on NMEA 2000) bit 24: data page (DP) bits 23-16: PDU format (PF) bits 15-8: PDU specific (PS) bits 7-0: source address
PF >= 240 (PDU2, broadcast): PGN = DP<<16 | PF<<8 | PS PF < 240 (PDU1, addressed): PGN = DP<<16 | PF<<8, PS = destination
type NameEncodeFields ¶ added in v0.4.0
type NameEncodeFields struct {
UniqueNumber uint32
ManufacturerCode uint16
DeviceInstance uint8
DeviceFunction uint8
DeviceClass uint8
SystemInstance uint8
IndustryGroup uint8
ArbitraryAddressCapable bool
}
EncodeName builds a 64-bit ISO NAME from individual fields. Inverse of DecodeNAME (at the numeric level; manufacturer string is ignored).
Fields map to the same bit layout documented on DecodeNAME:
bits 0-20: UniqueNumber (21 bits) bits 21-31: ManufacturerCode (11 bits) bits 32-34: DeviceInstance lower 3 bits bits 35-39: DeviceInstance upper 5 bits bits 40-47: DeviceFunction (8 bits) bit 48: reserved (0) bits 49-55: DeviceClass (7 bits) bits 56-59: SystemInstance (4 bits) bits 60-62: IndustryGroup (3 bits) bit 63: ArbitraryAddressCapable
type NameFields ¶
type NameFields struct {
NAMEHex string
Manufacturer string
ManufacturerCode uint16
DeviceClass uint8
DeviceFunction uint8
DeviceInstance uint8
UniqueNumber uint32
}
NameFields holds the decoded fields from a 64-bit ISO NAME (PGN 60928).
func DecodeNAME ¶
func DecodeNAME(name uint64) NameFields
DecodeNAME parses the 64-bit ISO NAME field from PGN 60928.
NAME field bit layout (64 bits, little-endian):
bits 0-20: unique number (21 bits) bits 21-31: manufacturer code (11 bits) bits 32-34: device instance lower (3 bits) bits 35-39: device instance upper (5 bits) bits 40-47: device function (8 bits) bit 48: reserved bits 49-55: device class (7 bits) bits 56-59: system instance (4 bits) bits 60-62: industry group (3 bits) bit 63: arbitrary address capable
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