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🛰️ GPSD client for Go.

Home Page: https://pkg.go.dev/github.com/stratoberry/go-gpsd

License: MIT License

Go 100.00%

gps-library gpsd golang

go-gpsd's Introduction

go-gpsd

GPSD client for Go.

Installation

# go get github.com/stratoberry/go-gpsd

go-gpsd has no external dependencies.

Usage

go-gpsd is a streaming client for GPSD's JSON service and as such can be used only in async manner unlike clients for other languages which support both async and sync modes.

import ("github.com/stratoberry/go-gpsd")

func main() {
	gps, err := gpsd.Dial("localhost:2947")
	if err != nil { panic(err) }
}

After Dialing the server, you should install stream filters. Stream filters allow you to capture only certain types of GPSD reports.

gps.AddFilter("TPV", tpvFilter)

Filter functions have a type of gps.Filter and should receive one argument of type interface{}.

tpvFilter := func(r interface{}) {
	report := r.(*gpsd.TPVReport)
	fmt.Println("Location updated", report.Lat, report.Lon)
}

Due to the nature of GPSD reports your filter will manually have to cast the type of the argument it received to a proper *gpsd.Report struct pointer.

After installing all needed filters, call the Watch method to start observing reports. Please note that at this time installed filters can't be removed.

done := gps.Watch()
<-done
// ...some time later...
gps.Close()

Watch() spans a new goroutine in which all data processing will happen, done doesn't send anything.

Currently supported GPSD report types

VERSION (gpsd.VERSIONReport)
TPV (gpsd.TPVReport)
SKY (gpsd.SKYReport)
ATT (gpsd.ATTReport)
GST (gpsd.GSTReport)
PPS (gpsd.PPSReport)
TOFF (gpsd.TOFFReport)
DEVICES (gpsd.DEVICESReport)
DEVICE (gpsd.DEVICEReport)
ERROR (gpsd.ERRORReport)

Documentation

For complete library documentation visit Go Reference.

Documentation of GPSD's JSON protocol is available at https://gpsd.gitlab.io/gpsd/gpsd_json.html.

References

This library was originally developed as a part of a student project at FOI/University of Zagreb.

go-gpsd's People

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go-gpsd's Issues

Missing License

I can not find the license terms anywhere. Would you mind adding a License file ?

go get not working

$ go get github.com/stratoberry/go-gpsd
go: github.com/stratoberry/go-gpsd: invalid github.com import path "github.com/stratoberry"

JSON parsing error panic

Not sure what to do about this, how to catch it or if it's my fault

I'm talking to GPSd on another machine across an (admittedly terrible) wireless connction instead of localhost. I expect that the connection is causing split packets or something and the JSON parsing fails

GPS location updated 50.335434 -0.1409792
GPS location updated 50.3354333 -0.1409808
GPS location updated 50.3354333 -0.1409808
GPS location updated 50.3354322 -0.1409816
GPS location updated 50.3354322 -0.1409816
JSON parsing error: invalid character 's' looking for beginning of value
JSON parsing error: invalid character ':' looking for beginning of value
JSON parsing error: unexpected end of JSON input
JSON parsing error: unexpected end of JSON input
panic: runtime error: slice bounds out of range [1460:510]

goroutine 35 [running]:
bufio.(*Reader).ReadSlice(0xc000308000, 0x70?)
        C:/Program Files/Go/src/bufio/bufio.go:354 +0x225
bufio.(*Reader).collectFragments(0xc00021fe10?, 0xc5?)
        C:/Program Files/Go/src/bufio/bufio.go:454 +0x6d
bufio.(*Reader).ReadString(0x7ff679041a60?, 0x80?)
        C:/Program Files/Go/src/bufio/bufio.go:501 +0x1f
github.com/stratoberry/go-gpsd.watch(0x0?, 0xc000306000)
        C:/Users/Joe/go/pkg/mod/github.com/stratoberry/[email protected]/gpsd.go:283 +0x45
created by github.com/stratoberry/go-gpsd.(*Session).Watch in goroutine 1
        C:/Users/Joe/go/pkg/mod/github.com/stratoberry/[email protected]/gpsd.go:233 +0xae
        ```

How to end go-gpsd watch thread gracefully?

I see a way how the watch go-routine can report that it ended, but no Close() or Shutdown() command to end it from the outside.

go get github.com/stratoberry/go-gpsd returns an error

IIf I type:

go get github.com/stratoberry/go-gpsd

then the following compiler error is shown (with the GOPATH part of the path replaced by $GOPATH by me):

# $GOPATH/src/github.com/stratoberry/go-gpsd/gpsd.go:170: line declared and not used

'line' is an unused variable in the Dial function.