gpsfeed

README

Overview

• library to handle gps nmea emitting devices via bufio.Scanner interface
• automatic recovery (watchdog), handling cecksums,
• can detect if the devices is unresponsive, emitts defective frames, disconnects, missbehaves ...
• 100 % pure go, stdlib only, no external dependencies
• see api.go for more details, cmd/gpsfeed for an example app

Documentation

Overview

package gpsfeed

package gpsfeed ...

Index

• Constants
• func CheckSumTag(sentence string) string
• func CheckSumValid(sentence string) bool
• func GetDeviceName(arg, old string) string
• type GpsDevice
  • func (dev *GpsDevice) CheckErrAdd() bool
  • func (dev *GpsDevice) Close()
  • func (dev *GpsDevice) GetErr() string
  • func (dev *GpsDevice) Open()

Constants

const DeviceTimeout = _deviceDataValidTimeout + 1 // wait before try to access device again

DeviceTimeout ...

Functions

func CheckSumTag

func CheckSumTag(sentence string) string

CheckSumTag calculates the NMEA sentence CheckSum and returns an tag string [ok|fail]

func CheckSumValid

func CheckSumValid(sentence string) bool

CheckSumValid validates an NMEA sentence checksum

func GetDeviceName

func GetDeviceName(arg, old string) string

GetDeviceName ...

Types

type GpsDevice

type GpsDevice struct {
	FileIO     string         // file name, eg. /dev/gps0
	Feed       *bufio.Scanner // line feed
	ErrCount   atomic.Uint64  // global err counter
	InitDone   atomic.Bool    // initial time sync done
	Responsive atomic.Bool    // feed state [responsive/unresponsive]
	DataValid  atomic.Bool    // feed state [datavalid/invalidutput]]
	Dog        atomic.Bool    // watchdog state
	Lock       sync.Mutex     // global device lock
	Handle     *os.File       // file handle
	Global     sync.WaitGroup // global state
}

GpsDevice holds all the feed, locks and handles for a specifc gps input device dongle

func (*GpsDevice) CheckErrAdd

func (dev *GpsDevice) CheckErrAdd() bool

CheckErrAdd validates the current number of global errors

func (*GpsDevice) Close

func (dev *GpsDevice) Close()

Close ...

func (*GpsDevice) GetErr

func (dev *GpsDevice) GetErr() string

GetErr returns the number of errors assoc with this device

func (*GpsDevice) Open

func (dev *GpsDevice) Open()

Open ...