go-gpsd

GPSD client for Go.

Installation

This version of go-gpsd requires Go 1.7.

go get github.com/dotpy3/go-gpsd

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.

This fork of the original go-gpsd adds support for the context package, and programmatic error handling.

import "github.com/dotpy3/go-gpsd"

func main() {
	gps := gpsd.Dial("localhost:2947")
}

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.

ctx, cancel := context.WithCancel()
gps.Watch(ctx)
<-time.After(30 * time.Second)
cancel()

Watch() will span a new goroutine in which all data processing will happen. In this case, this goroutine will be stopped after 30 seconds.

To handle errors, call the OnError method, with a function taking an error as an argument.

gps.OnError(func (err error) {
	fmt.Println("Error:", err)
})

Currently supported GPSD report types

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

Documentation

For complete library docs, visit GoDoc.org or take a look at the gpsd.go file in this repository.

GPSD's documentation on their JSON protocol can be found at http://catb.org/gpsd/gpsd_json.html