add onstart callback, throw error for set functions

cmd/gobot/main.go

@@ -13,9 +13,14 @@ func main() {
 	a := gk.NewAdaptorTCP("127.0.0.1:3333")
 	kb := gk.NewDriver(a)
 
+	kb.OnStart(func() {
+		kb.SetGyroTolerance(0)
+	})
+
 	work := func() {
-		kb.OnWheelsCurrent(func(w *ks.CurrentWheels) {
-			log.Printf("%d:%d", w.LeftMotor, w.RightMotor)
+
+		kb.OnGyro(func(g *ks.GyroData) {
+			log.Printf("%f : %f : %f", g.X, g.Y, g.Z)
 		})
 
 		gobot.Every(1*time.Minute, func() {

gobot/driver.go

@@ -1,6 +1,7 @@
 package kobuki
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/tinogoehlert/gobuki/commands"
@@ -52,6 +53,7 @@ const (
 type Driver struct {
 	name    string
 	adaptor *Adaptor
+	started func()
 	gobot.Eventer
 }
 
@@ -93,7 +95,7 @@ func (d *Driver) SetName(s string) {
 // Start initiates the Driver
 func (d *Driver) Start() error {
 	d.adaptor.bot.Start()
-
+	d.started()
 	d.adaptor.bot.OnAll(func(name string, data interface{}) {
 		d.Publish(name, data)
 	})
@@ -108,18 +110,30 @@ func (d *Driver) Halt() error {
 }
 
 // SetCliffADCTolerance set tolerance for Cliff ADC
-func (d *Driver) SetCliffADCTolerance(t int) {
+func (d *Driver) SetCliffADCTolerance(t int) error {
+	if d.adaptor.bot == nil {
+		return errors.New("driver not started")
+	}
 	d.adaptor.bot.SetCliffADCTolerance(t)
+	return nil
 }
 
 // SetGyroTolerance set tolerance for gyroscope
-func (d *Driver) SetGyroTolerance(t float64) {
+func (d *Driver) SetGyroTolerance(t float64) error {
+	if d.adaptor.bot == nil {
+		return errors.New("driver not started")
+	}
 	d.adaptor.bot.SetGyroTolerance(t)
+	return nil
 }
 
 // SetCurrentWheelsTolerance set tolerance for wheels current
-func (d *Driver) SetCurrentWheelsTolerance(t int) {
+func (d *Driver) SetCurrentWheelsTolerance(t int) error {
+	if d.adaptor.bot == nil {
+		return errors.New("driver not started")
+	}
 	d.adaptor.bot.SetCurrentWheelsTolerance(t)
+	return nil
 }
 
 // Move moves the robot
@@ -137,6 +151,11 @@ func (d *Driver) Connection() gobot.Connection {
 	return d.adaptor
 }
 
+// OnStart triggered when driver was started, useful for setup
+func (d *Driver) OnStart(f func()) {
+	d.started = f
+}
+
 // OnGyro new GyroData available
 func (d *Driver) OnGyro(f func(*sensors.GyroData)) {
 	d.adaptor.bot.On(GyroEvent, func(data interface{}) {