gps: improvements and corrections for config commands

This contains some improvements and corrections for the gps driver
It adds some additional functions for different modes (automobile, bike, etc)
and also ignores the return results from any config commands.

Basically due to the fact that there is a constant stream of updates
coming from NMEA messages, the results from sending any UBX commands
are getting lost. Better to just ignore them for now.

Signed-off-by: deadprogram <ron@hybridgroup.com>

gps/ublox.go

@@ -4,9 +4,8 @@ import (
 	"time"
 )
 
-// FlightModeCmd is a UBX-CFG-NAV5 command to set the GPS into
-// flight mode (airborne <1g)
-var flightModeCmd = CfgNav5{
+// FlightModeCmd is a UBX-CFG-NAV5 command
+var nav5Cmd = CfgNav5{
 	Mask:                  CfgNav5Dyn | CfgNav5MinEl | CfgNav5PosFixMode,
 	DynModel:              DynModeAirborne1g, // Airborne with <1g acceleration
 	FixMode:               FixModeAuto,       // Auto 2D/3D
@@ -29,7 +28,37 @@ var flightModeCmd = CfgNav5{
 
 // SetFlightMode sends UBX-CFG-NAV5 command to set GPS into flight mode
 func (d *Device) SetFlightMode() (err error) {
-	flightModeCmd.Put42Bytes(d.buffer[:])
+	nav5Cmd.DynModel = DynModeAirborne1g
+	nav5Cmd.FixMode = FixModeAuto
+	nav5Cmd.Put42Bytes(d.buffer[:])
+
+	return d.SendCommand(d.buffer[:42])
+}
+
+// SetPedestrianMode sends UBX-CFG-NAV5 command to set GPS into pedestrian mode
+func (d *Device) SetPedestrianMode() (err error) {
+	nav5Cmd.DynModel = DynModePedestrian
+	nav5Cmd.FixMode = FixModeAuto
+	nav5Cmd.Put42Bytes(d.buffer[:])
+
+	return d.SendCommand(d.buffer[:42])
+}
+
+// SetAutomotiveMode sends UBX-CFG-NAV5 command to set GPS into automotive mode
+func (d *Device) SetAutomotiveMode() (err error) {
+	nav5Cmd.DynModel = DynModeAutomotive
+	nav5Cmd.FixMode = FixModeAuto
+	nav5Cmd.Put42Bytes(d.buffer[:])
+
+	return d.SendCommand(d.buffer[:42])
+}
+
+// SetBikeMode sends UBX-CFG-NAV5 command to set GPS into bike mode
+func (d *Device) SetBikeMode() (err error) {
+	nav5Cmd.DynModel = DynModeBike
+	nav5Cmd.FixMode = FixModeAuto
+	nav5Cmd.Put42Bytes(d.buffer[:])
+
 	return d.SendCommand(d.buffer[:42])
 }
 
@@ -44,19 +73,19 @@ var (
 	messageRateGLLCmd = CfgMsg1{
 		MsgClass: 0xF0,
 		MsgID:    0x01,
-		Rate:     0, // Disabled
+		Rate:     1, // Every position fix
 	}
 	// GSA (satellite id list)
 	messageRateGSACmd = CfgMsg1{
 		MsgClass: 0xF0,
 		MsgID:    0x02,
-		Rate:     1, // Every position fix
+		Rate:     0, // Disabled
 	}
 	// GSV (satellite locations)
 	messageRateGSVCmd = CfgMsg1{
 		MsgClass: 0xF0,
 		MsgID:    0x03,
-		Rate:     1, // Every position fix
+		Rate:     0, // Every position fix
 	}
 	// RMC (time, lat/lng, speed, course)
 	messageRateRMCCmd = CfgMsg1{
@@ -84,18 +113,19 @@ var (
 	}
 )
 
-// SetMessageRatesMinimal configures the GPS to output a minimal set of NMEA sentences
+// SetMessageRatesMinimal configures the GPS to output a minimal set of NMEA sentences:
+// GSV, GGA, GLL, and RMC only.
 func SetMessageRatesMinimal(d *Device) (err error) {
 	commands := []CfgMsg1{
 		messageRateGSACmd,
-		messageRateGGACmd,
 		messageRateGLLCmd,
-		messageRateGSVCmd,
-		messageRateRMCCmd,
 		messageRateVTGCmd,
 		messageRateZDACmd,
 		messageRateTXTCmd,
 	}
+	for i := range commands {
+		commands[i].Rate = 0 // Disable
+	}
 	return setCfg1s(d, commands)
 }
 
@@ -111,18 +141,26 @@ func SetMessageRatesAllEnabled(d *Device) (err error) {
 		messageRateZDACmd,
 		messageRateTXTCmd,
 	}
+	for i := range commands {
+		commands[i].Rate = 1 // Enable
+	}
 	return setCfg1s(d, commands)
 }
 
 func setCfg1s(d *Device, commands []CfgMsg1) (err error) {
 	var buf [9]byte
 	for _, cmd := range commands {
-		cmd.Put9Bytes(buf[:9])
-		if err = d.SendCommand(buf[:9]); err != nil {
-			return err
-		}
+		cmd.Put9Bytes(buf[:])
+		// TODO handle errors differently here?
+		// This implementation just saves the last error and continues.
+		// Due to the GPS modules sending updates asynchronously
+		// the response is interleaved along with regular ASCII
+		// NMEA messages.
+		err = d.SendCommand(buf[:])
+		time.Sleep(100 * time.Millisecond)
 	}
-	return nil
+
+	return
 }
 
 // gnssDisableCmd is a UBX-CFG-GNSS command to disable all GNSS but GPS
@@ -146,6 +184,7 @@ func (d *Device) SetGNSSDisable() (err error) {
 	if err != nil {
 		return err
 	}
+
 	return d.SendCommand(d.buffer[:])
 }