single

Documentation

Overview

Package single implements a single-wire odometer, such as LM393, as an encoder. This allows the attached motor to determine its relative position. This class of encoders requires a single digital interrupt pin.

This encoder must be connected to a motor (or another component that supports encoders and reports the direction it is moving) in order to record readings. The motor indicates in which direction it is spinning, thus indicating if the encoder should increment or decrement reading value.

Resetting a position must set the position to an int64. A floating point input will be rounded.

Sample configuration:

{
	"pins" : {
		"i": 10
	},
	"board": "pi"
}

Index

• func NewSingleEncoder(ctx context.Context, deps resource.Dependencies, conf resource.Config, ...) (encoder.Encoder, error)
• type Config
  • func (conf *Config) Validate(path string) ([]string, error)
• type DirectionAware
• type Encoder
  • func (e *Encoder) AttachDirectionalAwareness(da DirectionAware)
  • func (e *Encoder) Close(ctx context.Context) error
  • func (e *Encoder) Position(ctx context.Context, positionType encoder.PositionType, ...) (float64, encoder.PositionType, error)
  • func (e *Encoder) Properties(ctx context.Context, extra map[string]interface{}) (encoder.Properties, error)
  • func (e *Encoder) Reconfigure(ctx context.Context, deps resource.Dependencies, conf resource.Config) error
  • func (e *Encoder) ResetPosition(ctx context.Context, extra map[string]interface{}) error
• type Pin

Functions

func NewSingleEncoder

func NewSingleEncoder(
	ctx context.Context,
	deps resource.Dependencies,
	conf resource.Config,
	logger logging.Logger,
) (encoder.Encoder, error)

NewSingleEncoder creates a new Encoder.

Types

type Config

type Config struct {
	Pins      Pin    `json:"pins"`
	BoardName string `json:"board"`
}

Config describes the configuration of a single encoder.

func (*Config) Validate

func (conf *Config) Validate(path string) ([]string, error)

Validate ensures all parts of the config are valid.

type DirectionAware

type DirectionAware interface {
	DirectionMoving() int64
}

DirectionAware lets you ask what direction something is moving. Only used for Encoder for now, unclear future. DirectionMoving returns -1 if the motor is currently turning backwards, 1 if forwards and 0 if off.

type Encoder

type Encoder struct {
	resource.Named

	I board.DigitalInterrupt
	// contains filtered or unexported fields
}

Encoder keeps track of a motor position using a rotary encoder.s.

func (*Encoder) AttachDirectionalAwareness

func (e *Encoder) AttachDirectionalAwareness(da DirectionAware)

AttachDirectionalAwareness to pre-created encoder.

func (*Encoder) Close

func (e *Encoder) Close(ctx context.Context) error

Close shuts down the Encoder.

func (*Encoder) Position

func (e *Encoder) Position(
	ctx context.Context,
	positionType encoder.PositionType,
	extra map[string]interface{},
) (float64, encoder.PositionType, error)

Position returns the current position in terms of ticks or degrees, and whether it is a relative or absolute position.

func (*Encoder) Properties

func (e *Encoder) Properties(ctx context.Context, extra map[string]interface{}) (encoder.Properties, error)

Properties returns a list of all the position types that are supported by a given encoder.

func (*Encoder) Reconfigure

func (e *Encoder) Reconfigure(
	ctx context.Context,
	deps resource.Dependencies,
	conf resource.Config,
) error

Reconfigure atomically reconfigures this encoder in place based on the new config.

func (*Encoder) ResetPosition

func (e *Encoder) ResetPosition(ctx context.Context, extra map[string]interface{}) error

ResetPosition sets the current position of the motor (adjusted by a given offset).

type Pin

type Pin struct {
	I string `json:"i"`
}

Pin describes the configuration of Pins for a Single encoder.