Update sphero package error handling

platforms/sphero/sphero_adaptor.go

@@ -13,7 +13,7 @@ var _ gobot.AdaptorInterface = (*SpheroAdaptor)(nil)
 type SpheroAdaptor struct {
 	gobot.Adaptor
 	sp      io.ReadWriteCloser
-	connect func(*SpheroAdaptor)
+	connect func(*SpheroAdaptor) (err error)
 }
 
 // NewSpheroAdaptor returns a new SpheroAdaptor given a name and port
@@ -24,28 +24,31 @@ func NewSpheroAdaptor(name string, port string) *SpheroAdaptor {
 			"SpheroAdaptor",
 			port,
 		),
-		connect: func(a *SpheroAdaptor) {
+		connect: func(a *SpheroAdaptor) (err error) {
 			c := &serial.Config{Name: a.Port(), Baud: 115200}
 			s, err := serial.OpenPort(c)
 			if err != nil {
-				panic(err)
+				return err
 			}
 			a.sp = s
+			return
 		},
 	}
 }
 
 // Connect initiates a connection to the Sphero. Returns true on successful connection.
-func (a *SpheroAdaptor) Connect() error {
-	a.connect(a)
+func (a *SpheroAdaptor) Connect() (err error) {
+	if err = a.connect(a); err != nil {
+		return
+	}
 	a.SetConnected(true)
-	return nil
+	return
 }
 
 // Reconnect attempts to reconnect to the Sphero. If the Sphero has an active connection
 // it will first close that connection and then establish a new connection.
 // Returns true on Successful reconnection
-func (a *SpheroAdaptor) Reconnect() error {
+func (a *SpheroAdaptor) Reconnect() (err error) {
 	if a.Connected() == true {
 		a.Disconnect()
 	}
@@ -53,8 +56,10 @@ func (a *SpheroAdaptor) Reconnect() error {
 }
 
 // Disconnect terminates the connection to the Sphero. Returns true on successful disconnect.
-func (a *SpheroAdaptor) Disconnect() error {
-	a.sp.Close()
+func (a *SpheroAdaptor) Disconnect() (err error) {
+	if err = a.sp.Close(); err != nil {
+		return
+	}
 	a.SetConnected(false)
 	return nil
 }

platforms/sphero/sphero_adaptor_test.go

@@ -8,7 +8,7 @@ import (
 func initTestSpheroAdaptor() *SpheroAdaptor {
 	a := NewSpheroAdaptor("bot", "/dev/null")
 	a.sp = gobot.NullReadWriteCloser{}
-	a.connect = func(a *SpheroAdaptor) {}
+	a.connect = func(a *SpheroAdaptor) (err error) { return nil }
 	return a
 }
 

platforms/sphero/sphero_driver.go

@@ -3,7 +3,7 @@ package sphero
 import (
 	"bytes"
 	"encoding/binary"
-	"fmt"
+	"errors"
 	"time"
 
 	"github.com/hybridgroup/gobot"
@@ -60,6 +60,7 @@ func NewSpheroDriver(a *SpheroAdaptor, name string) *SpheroDriver {
 		responseChannel: make(chan []uint8, 1024),
 	}
 
+	s.AddEvent("error")
 	s.AddEvent("collision")
 	s.AddCommand("SetRGB", func(params map[string]interface{}) interface{} {
 		r := uint8(params["r"].(float64))
@@ -114,11 +115,14 @@ func (s *SpheroDriver) adaptor() *SpheroAdaptor {
 //
 // Emits the Events:
 // 	"collision" SpheroDriver.Collision - On Collision Detected
-func (s *SpheroDriver) Start() error {
+func (s *SpheroDriver) Start() (err error) {
 	go func() {
 		for {
 			packet := <-s.packetChannel
-			s.write(packet)
+			err = s.write(packet)
+			if err != nil {
+				gobot.Publish(s.Event("error"), err)
+			}
 		}
 	}()
 
@@ -265,20 +269,17 @@ func (s *SpheroDriver) craftPacket(body []uint8, did byte, cid byte) *packet {
 	return packet
 }
 
-func (s *SpheroDriver) write(packet *packet) {
+func (s *SpheroDriver) write(packet *packet) (err error) {
 	buf := append(packet.header, packet.body...)
 	buf = append(buf, packet.checksum)
 	length, err := s.adaptor().sp.Write(buf)
 	if err != nil {
-		fmt.Println(s.Name, err)
-		s.adaptor().Disconnect()
-		fmt.Println("Reconnecting to SpheroDriver...")
-		s.adaptor().Connect()
-		return
+		return err
 	} else if length != len(buf) {
-		fmt.Println("Not enough bytes written", s.Name)
+		return errors.New("Not enough bytes written")
 	}
 	s.seq++
+	return
 }
 
 func (s *SpheroDriver) calculateChecksum(packet *packet) uint8 {