NMEA pass-through mode

README.md

@@ -42,14 +42,21 @@ cmdline_init: ""
 vara_mode: false
 ```
 
+Next time ptb will start using the settings in your config file.
+
+## Settings
+
+The meaning of the vables in the config file are as follows:
+
 | Variable          | Meaning                                                                                                        |
-|-------------------|-----------------------------------------------------------------------------------------------------------------------------|
+|-------------------|----------------------------------------------------------------------------------------------------------------|
 | `device`          | Path to the serial device where the modem is connected **or** `tcp://address:port` (useful for Android)        |
 | `baudrate`        | baud rate of the modem                                                                                         |
 | `mycall`          | The callsign to be used on HF                                                                                  |
 | `server_address`  | server socket address for the **commands**                                                                     |
 | `data_address`    | server socket address for the **data**                                                                         |
 | `gpsd_address`    | **optional** See the chapter about GPS below                                                                   |  
+| `nmeapassthrough` | **only when gpsd_address has been set** bool value: if true pass NMEA data trough instead of interpreting them |  
 | `cmdline_init`    | extra commands sent to the modem before going into hostmode, separated by semicolons, Ex: `DISP BR 1;DISP A 1;DISP DIMMOFF` |
 | `vara_mode`       | see the chapter about the VARA mode                                                                            |
 
@@ -97,7 +104,9 @@ to make your position visible to Pat (or any other gpsd client).
 
 To configure it you just need to add a line like
 
-`gpsd_address: 0.0.0.0:2947`
+```yaml
+gpsd_address: 0.0.0.0:2947`
+```
 
 to the config file. In Pat, a possible counterpart could look like this:
 
@@ -110,6 +119,19 @@ to the config file. In Pat, a possible counterpart could look like this:
 },
 ```
 
+### NMEA Pass-Through
+
+If you need the **raw** NMEA data (for example if your GPS is not supported by the built-in mini-gpsd, or you want to 
+run your own gpsd), set `nmeapassthough` to `true`, for example:
+
+```yaml
+gpsd_address: 0.0.0.0:8888
+nmeapassthough: true
+```
+
+Note that if you plan to use Pat, you'd need to run `gpsd` to use
+the position of the GNSS receiver.
+
 ## How to run
 
 As a rule of thumb, you have to start the PACTOR-TCP-bridge before you want to use

gpsd.go

@@ -130,6 +130,20 @@ func isNetConnClosedErr(err error) bool {
 }
 func addClient(client net.Conn) {
 
+	if s.NMEAPassthrough {
+		go func() {
+			defer func() {
+				client.Close()
+				removeClient(client)
+				writeDebug(fmt.Sprintf("GPSd Client disconnected: %v\n", client.RemoteAddr()), 0)
+			}()
+			rd := bufio.NewScanner(client)
+			for rd.Scan() {
+				writeDebug(fmt.Sprintf("GPSd Client received message: %v\n", rd.Text()), 0)
+			}
+		}()
+
+	} else {
 		_, err := client.Write([]byte("{\"class\":\"VERSION\",\"release\":\"3.25\",\"rev\":\"3.25\",\"proto_major\":3,\"proto_minor\":15}\n"))
 		if err != nil {
 			writeDebug(fmt.Sprintf("Error writing to client: %v\n", err), 1)
@@ -147,7 +161,6 @@ func addClient(client net.Conn) {
 				time.Sleep(100 * time.Millisecond)
 				// looks like gpsd does not expect \n terminated lines so read what is there from the socket
 				client.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
-			if true {
 				buff := make([]byte, 1024)
 				n, err := rd.Read(buff)
 				if isNetConnClosedErr(err) {
@@ -197,9 +210,8 @@ func addClient(client net.Conn) {
 
 				}
 			}
-		}
 		}()
-
+	}
 	// register the client, so it gets updates from now on
 	clientMutex.Lock()
 	clients[client] = struct{}{}
@@ -224,6 +236,16 @@ func publishTPV() {
 
 func readAndBroadcast() {
 	device := s.DeviceType
+	if s.NMEAPassthrough {
+		for {
+			nmeaSentence, err := s.GPSStream.DequeueOrWait()
+			if err != nil {
+				writeDebug(fmt.Sprintf("Error dequeuing GPS sentence: %v\n", err), 0)
+				continue
+			}
+			broadcastToClients(nmeaSentence)
+		}
+	} else {
 		for {
 			nmeaSentence, err := s.GPSStream.DequeueOrWait()
 			if err != nil {
@@ -286,6 +308,7 @@ func readAndBroadcast() {
 			}
 		}
 	}
+}
 
 func parseTime(gpstime string) string {
 	// Remove any extra milliseconds after 3 digits (if needed)

main.go

@@ -35,6 +35,7 @@ type TCPServer struct {
 	VARAMode        bool
 	DaemonMode      bool
 	GPSdMode        bool
+	NMEAPassthrough bool
 	DeviceType      string
 	Status          uint8
 	Command         struct {
@@ -48,7 +49,7 @@ type TCPServer struct {
 	GPSStream *StringFIFO // NMEA steam from PTC to gpsd server, see gpsd.go
 }
 
-func NewTCPServer(varamode bool, daemonmode bool, gpsdmode bool) *TCPServer {
+func NewTCPServer(varamode bool, daemonmode bool, gpsdmode bool, nmeapassthrough bool) *TCPServer {
 	return &TCPServer{
 		Protocol:        make(chan string, 1024),
 		ToPactor:        NewByteFIFO(1024),
@@ -56,6 +57,7 @@ func NewTCPServer(varamode bool, daemonmode bool, gpsdmode bool) *TCPServer {
 		VARAMode:        varamode,
 		DaemonMode:      daemonmode,
 		GPSdMode:        gpsdmode,
+		NMEAPassthrough: nmeapassthrough,
 		DeviceType:      "",
 		Status:          0,
 		Command: struct {
@@ -77,6 +79,7 @@ type Userconfig struct {
 	ServerAddress     string `yaml:"server_address"`
 	DataAddress       string `yaml:"data_address"`
 	GPSdAddress       string `yaml:"gpsd_address"`
+	NMEAPassthrough   bool   `yaml:"nmeapassthrough"`
 	CmdLineInit       string `yaml:"cmdline_init"`
 	StartwithVaraMode bool   `yaml:"vara_mode"`
 }
@@ -94,6 +97,7 @@ func configmanage(Config *Userconfig, path string) error {
 			ServerAddress:     "127.0.0.1:8300",
 			DataAddress:       "127.0.0.1:8301",
 			GPSdAddress:       "",
+			NMEAPassthrough:   false,
 			CmdLineInit:       "",
 			StartwithVaraMode: false}
 
@@ -158,7 +162,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	s = NewTCPServer(Config.StartwithVaraMode, daemonMode, Config.GPSdAddress != "")
+	s = NewTCPServer(Config.StartwithVaraMode, daemonMode, Config.GPSdAddress != "", Config.NMEAPassthrough)
 	fmt.Println("Initializing PACTOR modem, please wait...")
 	m, err := OpenModem(Config.Device, Config.Baudrate, Config.Mycall, "", Config.CmdLineInit)
 	if err != nil {