gotelem/frame.go
2023-09-19 14:17:22 -05:00

60 lines
1.7 KiB
Go

// Package can provides generic CAN interfaces and types.
//
// It has a generic can Frame (packet), as well as a filter type.
// we also define standard interfaces for objects that can accept
// can frames. We can use this pattern to easily extend the capabiltiies of the program
// by writing "adapters" to various devices/formats (xbee, sqlite, network socket, socketcan)
package gotelem
// Frame represents a protocol-agnostic CAN frame. The Id can be standard or extended,
// but if it is extended, the Kind should be EFF.
type Frame struct {
Id uint32
Data []byte
Kind Kind
}
type CANFrame interface {
Id() uint32
Data() []byte
Type() Kind
}
//go:generate stringer -output=frame_kind.go -type Kind
// Kind is the type of the can Frame
type Kind uint8
const (
CanSFFFrame Kind = iota // Standard ID Frame
CanEFFFrame // Extended ID Frame
CanRTRFrame // Remote Transmission Request Frame
CanErrFrame // Error Frame
)
// CanFilter is a basic filter for masking out data. It has an Inverted flag
// which indicates opposite behavior (reject all packets that match Id and Mask).
// The filter matches when (packet.Id & filter.Mask) == filter.Id
// TODO: is this needed anymore since we are using firmware based version instead?
type CanFilter struct {
Id uint32
Mask uint32
Inverted bool
}
// CanSink is an object that can accept Frames to transmit.
type CanSink interface {
Send(*Frame) error
}
// CanSource is an object that can receive Frames.
type CanSource interface {
Recv() (*Frame, error)
}
// CanTransciever is an object that can both send and receive Frames.
type CanTransciever interface {
CanSink
CanSource
}