Merge 1e7fa76 into 2310df0

README.md

@@ -17,6 +17,7 @@ After this command *go-nmea* is ready to use. Its source will be in:
 At this moment, this library supports the following sentence types:
 
 - [RMC](http://aprs.gids.nl/nmea/#rmc) - Recommended Minimum Specific GPS/Transit data
+- [PMTK](https://www.rhydolabz.com/documents/25/PMTK_A11.pdf) - Messages for setting and reading commands for MediaTek gps modules.
 - [GGA](http://aprs.gids.nl/nmea/#gga) - GPS Positioning System Fix Data
 - [GSA](http://aprs.gids.nl/nmea/#gsa) - GPS DOP and active satellites
 - [GSV](http://aprs.gids.nl/nmea/#gsv) - GPS Satellites in view

go.mod

@@ -1,3 +1,7 @@
 module github.com/adrianmo/go-nmea
 
-require github.com/stretchr/testify v1.2.1
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.2.1
+)

go.sum

@@ -0,0 +1,6 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.2.1 h1:52QO5WkIUcHGIR7EnGagH88x1bUzqGXTC5/1bDTUQ7U=
+github.com/stretchr/testify v1.2.1/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=

mtk.go

@@ -0,0 +1,25 @@
+package nmea
+
+const (
+	// TypeMTK type for PMTK sentences
+	TypeMTK = "PMTK"
+)
+
+// MTK is the Time, position, and fix related data of the receiver.
+type MTK struct {
+	BaseSentence
+	Cmd,
+	Flag int64
+}
+
+// newMTK constructor
+func newMTK(s BaseSentence) (MTK, error) {
+	p := newParser(s)
+	cmd := p.Int64(0, "command")
+	flag := p.Int64(1, "flag")
+	return MTK{
+		BaseSentence: s,
+		Cmd:          cmd,
+		Flag:         flag,
+	}, p.Err()
+}

sentence.go

@@ -88,6 +88,9 @@ func parseSentence(raw string) (BaseSentence, error) {
 
 // parsePrefix takes the first field and splits it into a talker id and data type.
 func parsePrefix(s string) (string, string) {
+	if strings.HasPrefix(s, "PMTK") {
+		return "PMTK", s[4:]
+	}
 	if strings.HasPrefix(s, "P") {
 		return "P", s[1:]
 	}
@@ -97,7 +100,7 @@ func parsePrefix(s string) (string, string) {
 	return s[:2], s[2:]
 }
 
-// xor all the bytes in a string an return it
+// xorChecksum xor all the bytes in a string an return it
 // as an uppercase hex string
 func xorChecksum(s string) string {
 	var checksum uint8
@@ -114,6 +117,12 @@ func Parse(raw string) (Sentence, error) {
 		return nil, err
 	}
 	if strings.HasPrefix(s.Raw, SentenceStart) {
+		// MTK message types share the same format
+		// so we return the same struct for all types.
+		switch s.Talker {
+		case TypeMTK:
+			return newMTK(s)
+		}
 		switch s.Type {
 		case TypeRMC:
 			return newRMC(s)