can

README

from https://github.com/einride/can-go tag v0.12.2 update 1、全局替换 go.einride.tech ---》 gitee.com/a-fuzz

git tag v0.12.2 git push origin v0.12.2

其他项目引用： 在go.mod中添加 gitee.com/a-fuzz/can v0.12.2

Documentation

Overview

Package can provides primitives for working with CAN.

See: https://en.wikipedia.org/wiki/CAN_bus

Index

• Constants
• func CheckBitRangeBigEndian(frameLength, rangeStart, rangeLength uint8) error
• func CheckBitRangeLittleEndian(frameLength, rangeStart, rangeLength uint8) error
• func CheckValue(value uint64, bits uint8) error
• type Data
  • func (d *Data) Bit(i uint8) bool
  • func (d *Data) PackBigEndian() uint64
  • func (d *Data) PackLittleEndian() uint64
  • func (d *Data) SetBit(i uint8, value bool)
  • func (d *Data) SetSignedBitsBigEndian(start, length uint8, value int64)
  • func (d *Data) SetSignedBitsLittleEndian(start, length uint8, value int64)
  • func (d *Data) SetUnsignedBitsBigEndian(start, length uint8, value uint64)
  • func (d *Data) SetUnsignedBitsLittleEndian(start, length uint8, value uint64)
  • func (d *Data) SignedBitsBigEndian(start, length uint8) int64
  • func (d *Data) SignedBitsLittleEndian(start, length uint8) int64
  • func (d *Data) UnpackBigEndian(packed uint64)
  • func (d *Data) UnpackLittleEndian(packed uint64)
  • func (d *Data) UnsignedBitsBigEndian(start, length uint8) uint64
  • func (d *Data) UnsignedBitsLittleEndian(start, length uint8) uint64
• type Frame
  • func (f Frame) JSON() string
  • func (f Frame) MarshalJSON() ([]byte, error)
  • func (f Frame) String() string
  • func (f *Frame) UnmarshalJSON(jsonData []byte) error
  • func (f *Frame) UnmarshalString(s string) error
  • func (f *Frame) Validate() error
• type FrameMarshaler
• type FrameUnmarshaler
• type Message

Constants

const (
	MaxID         = 0x7ff
	MaxExtendedID = 0x1fffffff
)

CAN format constants.

const MaxDataLength = 8

Functions

func CheckBitRangeBigEndian

func CheckBitRangeBigEndian(frameLength, rangeStart, rangeLength uint8) error

CheckBitRangeBigEndian checks that a big-endian bit range fits in the data.

func CheckBitRangeLittleEndian

func CheckBitRangeLittleEndian(frameLength, rangeStart, rangeLength uint8) error

CheckBitRangeLittleEndian checks that a little-endian bit range fits in the data.

func CheckValue

func CheckValue(value uint64, bits uint8) error

CheckValue checks that a value fits in a number of bits.

Types

type Data

type Data [MaxDataLength]byte

Data holds the data in a CAN frame.

Layout

Individual bits in the data are numbered according to the following scheme:

         BIT
         NUMBER
         +------+------+------+------+------+------+------+------+
         |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
BYTE     +------+------+------+------+------+------+------+------+
NUMBER
+-----+  +------+------+------+------+------+------+------+------+
|  0  |  |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
+-----+  +------+------+------+------+------+------+------+------+
|  1  |  |  15  |  14  |  13  |  12  |  11  |  10  |   9  |   8  |
+-----+  +------+------+------+------+------+------+------+------+
|  2  |  |  23  |  22  |  21  |  20  |  19  |  18  |  17  |  16  |
+-----+  +------+------+------+------+------+------+------+------+
|  3  |  |  31  |  30  |  29  |  28  |  27  |  26  |  25  |  24  |
+-----+  +------+------+------+------+------+------+------+------+
|  4  |  |  39  |  38  |  37  |  36  |  35  |  34  |  33  |  32  |
+-----+  +------+------+------+------+------+------+------+------+
|  5  |  |  47  |  46  |  45  |  44  |  43  |  42  |  41  |  40  |
+-----+  +------+------+------+------+------+------+------+------+
|  6  |  |  55  |  54  |  53  |  52  |  51  |  50  |  49  |  48  |
+-----+  +------+------+------+------+------+------+------+------+
|  7  |  |  63  |  62  |  61  |  60  |  59  |  58  |  57  |  56  |
+-----+  +------+------+------+------+------+------+------+------+

Bit ranges can be manipulated using little-endian and big-endian bit ordering.

Little-endian bit ranges

Example range of length 32 starting at bit 29:

         BIT
         NUMBER
         +------+------+------+------+------+------+------+------+
         |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
BYTE     +------+------+------+------+------+------+------+------+
NUMBER
+-----+  +------+------+------+------+------+------+------+------+
|  0  |  |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
+-----+  +------+------+------+------+------+------+------+------+
|  1  |  |  15  |  14  |  13  |  12  |  11  |  10  |   9  |   8  |
+-----+  +------+------+------+------+------+------+------+------+
|  2  |  |  23  |  22  |  21  |  20  |  19  |  18  |  17  |  16  |
+-----+  +------+------+------+------+------+------+------+------+
|  3  |  |  <-------------LSb |  28  |  27  |  26  |  25  |  24  |
+-----+  +------+------+------+------+------+------+------+------+
|  4  |  |  <--------------------------------------------------  |
+-----+  +------+------+------+------+------+------+------+------+
|  5  |  |  <--------------------------------------------------  |
+-----+  +------+------+------+------+------+------+------+------+
|  6  |  |  <--------------------------------------------------  |
+-----+  +------+------+------+------+------+------+------+------+
|  7  |  |  63  |  62  |  61  | <-MSb--------------------------- |
+-----+  +------+------+------+------+------+------+------+------+

Big-endian bit ranges

Example range of length 32 starting at bit 29:

         BIT
         NUMBER
         +------+------+------+------+------+------+------+------+
         |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
BYTE     +------+------+------+------+------+------+------+------+
NUMBER
+-----+  +------+------+------+------+------+------+------+------+
|  0  |  |   7  |   6  |   5  |   4  |   3  |   2  |   1  |   0  |
+-----+  +------+------+------+------+------+------+------+------+
|  1  |  |  15  |  14  |  13  |  12  |  11  |  10  |   9  |   8  |
+-----+  +------+------+------+------+------+------+------+------+
|  2  |  |  23  |  22  |  21  |  20  |  19  |  18  |  17  |  16  |
+-----+  +------+------+------+------+------+------+------+------+
|  3  |  |  31  |  30  | <-MSb---------------------------------  |
+-----+  +------+------+------+------+------+------+------+------+
|  4  |  |  <--------------------------------------------------  |
+-----+  +------+------+------+------+------+------+------+------+
|  5  |  |  <--------------------------------------------------  |
+-----+  +------+------+------+------+------+------+------+------+
|  6  |  |  <--------------------------------------------------  |
+-----+  +------+------+------+------+------+------+------+------+
|  7  |  |  <------LSb |  61  |  60  |  59  |  58  |  57  |  56  |
+-----+  +------+------+------+------+------+------+------+------+

func (*Data) Bit

func (d *Data) Bit(i uint8) bool

Bit returns the value of the i:th bit in the data as a bool.

func (*Data) PackBigEndian

func (d *Data) PackBigEndian() uint64

PackBigEndian packs the data into a contiguous uint64 value for big-endian signals.

func (*Data) PackLittleEndian

func (d *Data) PackLittleEndian() uint64

PackLittleEndian packs the data into a contiguous uint64 value for little-endian signals.

func (*Data) SetBit

func (d *Data) SetBit(i uint8, value bool)

SetBit sets the value of the i:th bit in the data.

func (*Data) SetSignedBitsBigEndian

func (d *Data) SetSignedBitsBigEndian(start, length uint8, value int64)

SetSignedBitsBigEndian sets the big-endian bit range [start, start+length) to the provided signed value.

func (*Data) SetSignedBitsLittleEndian

func (d *Data) SetSignedBitsLittleEndian(start, length uint8, value int64)

SetSignedBitsLittleEndian sets the little-endian bit range [start, start+length) to the provided signed value.

func (*Data) SetUnsignedBitsBigEndian

func (d *Data) SetUnsignedBitsBigEndian(start, length uint8, value uint64)

SetUnsignedBitsBigEndian sets the big-endian bit range [start, start+length) to the provided unsigned value.

func (*Data) SetUnsignedBitsLittleEndian

func (d *Data) SetUnsignedBitsLittleEndian(start, length uint8, value uint64)

SetUnsignedBitsBigEndian sets the little-endian bit range [start, start+length) to the provided unsigned value.

func (*Data) SignedBitsBigEndian

func (d *Data) SignedBitsBigEndian(start, length uint8) int64

SignedBitsBigEndian returns little-endian bit range [start, start+length) as a signed value.

func (*Data) SignedBitsLittleEndian

func (d *Data) SignedBitsLittleEndian(start, length uint8) int64

SignedBitsLittleEndian returns little-endian bit range [start, start+length) as a signed value.

func (*Data) UnpackBigEndian

func (d *Data) UnpackBigEndian(packed uint64)

UnpackBigEndian sets the value of d.Bytes by unpacking the provided value as sequential big-endian bits.

func (*Data) UnpackLittleEndian

func (d *Data) UnpackLittleEndian(packed uint64)

UnpackLittleEndian sets the value of d.Bytes by unpacking the provided value as sequential little-endian bits.

func (*Data) UnsignedBitsBigEndian

func (d *Data) UnsignedBitsBigEndian(start, length uint8) uint64

UnsignedBitsBigEndian returns the big-endian bit range [start, start+length) as an unsigned value.

func (*Data) UnsignedBitsLittleEndian

func (d *Data) UnsignedBitsLittleEndian(start, length uint8) uint64

UnsignedBitsLittleEndian returns the little-endian bit range [start, start+length) as an unsigned value.

type Frame

type Frame struct {
	// ID is the CAN ID
	ID uint32
	// Length is the number of bytes of data in the frame.
	Length uint8
	// Data is the frame data.
	Data Data
	// IsRemote is true for remote frames.
	IsRemote bool
	// IsExtended is true for extended frames, i.e. frames with 29-bit IDs.
	IsExtended bool
}

Frame represents a CAN frame.

A Frame is intentionally designed to fit into 16 bytes on common architectures and is therefore amenable to pass-by-value and judicious copying.

func (Frame) JSON

func (f Frame) JSON() string

JSON returns the JSON-encoding of f, using hex-encoding for the data.

Examples:

{"id":32,"data":"0102030405060708"}
{"id":32,"extended":true,"remote":true,"length":4}

func (Frame) MarshalJSON

func (f Frame) MarshalJSON() ([]byte, error)

MarshalJSON returns the JSON-encoding of f, using hex-encoding for the data.

See JSON for an example of the JSON schema.

func (Frame) String

func (f Frame) String() string

String returns an ASCII representation the CAN frame.

Format:

([0-9A-F]{3}|[0-9A-F]{3})#(R[0-8]?|[0-9A-F]{0,16})

The format is compatible with the candump(1) log file format.

func (*Frame) UnmarshalJSON

func (f *Frame) UnmarshalJSON(jsonData []byte) error

UnmarshalJSON sets *f using the provided JSON-encoded values.

See MarshalJSON for an example of the expected JSON schema.

The result should be checked with Validate to guard against invalid JSON data.

func (*Frame) UnmarshalString

func (f *Frame) UnmarshalString(s string) error

UnmarshalString sets *f using the provided ASCII representation of a Frame.

func (*Frame) Validate

func (f *Frame) Validate() error

Validate returns an error if the Frame is not a valid CAN frame.

type FrameMarshaler

type FrameMarshaler interface {
	MarshalFrame() (Frame, error)
}

FrameMarshaler can marshal itself to a CAN frame.

type FrameUnmarshaler

type FrameUnmarshaler interface {
	UnmarshalFrame(Frame) error
}

FrameUnmarshaler can unmarshal itself from a CAN frame.

type Message

type Message interface {
	FrameMarshaler
	FrameUnmarshaler
}

Message is anything that can marshal and unmarshal itself to/from a CAN frame.