Updated Android application, modified Arduino Sketch to stop in case of

loss of signal.

AndroidExplorerbotServer/res/layout/activity_main.xml

@@ -22,4 +22,31 @@
         android:text="@string/srv"
         android:textAppearance="?android:attr/textAppearanceLarge" />
 
+    <TextView
+        android:id="@+id/textView1"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_below="@+id/text"
+        android:layout_centerHorizontal="true"
+        android:layout_margin="10dp"
+        android:gravity="center_horizontal"
+        android:text="@string/explain" />
+
+    <Button
+        android:id="@+id/killserverbutton"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_below="@+id/textView1"
+        android:layout_centerHorizontal="true"
+        android:text="@string/killserver" />
+
+    <ImageButton
+        android:id="@+id/startvideo"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_alignParentRight="true"
+        android:layout_alignParentTop="true"
+        android:layout_margin="10dp"
+        android:src="@drawable/ic_device_access_video" />
+
 </RelativeLayout>

AndroidExplorerbotServer/res/values/strings.xml

@@ -3,5 +3,7 @@
 
     <string name="app_name">AndroidExplorerbotServer</string>
     <string name="srv">Server started</string>
+    <string name="explain">Exiting with HOME key will keep the server running. To exit completly press BACK or use the button below.</string>
+    <string name="killserver">Kill server</string>
 
 </resources>

AndroidExplorerbotServer/src/it/danieleverducci/explorerbotserver/AppConfiguration.java

@@ -21,4 +21,5 @@ package it.danieleverducci.explorerbotserver;
 public class AppConfiguration {
 	public static final int PORT=6787;	//The default server port
 	public static final boolean LOG_ENABLED=false;
+	public static final String DEFAULT_IPCAMERA_APP_PACKAGENAME="com.pas.webcam";
 }

AndroidExplorerbotServer/src/it/danieleverducci/explorerbotserver/MainActivity.java

@@ -23,10 +23,15 @@ import it.danieleverducci.explorerbot.objects.GamepadPosition;
 import java.io.IOException;
 
 import android.app.Activity;
+import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
+import android.view.View;
+import android.view.View.OnClickListener;
 
-public class MainActivity extends Activity implements OnControllerPolledListener {
+public class MainActivity extends Activity implements OnControllerPolledListener, OnClickListener {
 	private SerialCommunication serial;
+	private ServerNetworkCommunicationThread sct;
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
@@ -37,10 +42,13 @@ public class MainActivity extends Activity implements OnControllerPolledListener
 		serial = new SerialCommunication(this);
 
 		//Start network communication server
-		ServerNetworkCommunicationThread sct = new ServerNetworkCommunicationThread();
+		sct = new ServerNetworkCommunicationThread();
 		sct.setOnControllerPolledListener(this);
 		sct.start();
 
+		//Register interface buttons listener
+		findViewById(R.id.killserverbutton).setOnClickListener(this);
+		findViewById(R.id.startvideo).setOnClickListener(this);
 	}
 
 	@Override
@@ -56,6 +64,11 @@ public class MainActivity extends Activity implements OnControllerPolledListener
 
 	@Override
 	protected void onDestroy() {
+		//Terminate network thread
+		if(sct!=null && sct.isAlive()){
+			sct.setMustExit(true);
+		}
+		//Terminate serial connection to Arduino
 		if(serial!=null){
 			try {
 				serial.closeConnection();
@@ -66,4 +79,25 @@ public class MainActivity extends Activity implements OnControllerPolledListener
 		super.onDestroy();
 	}
 
+	@Override
+	public void onClick(View v) {
+		switch(v.getId()){
+		case R.id.killserverbutton:
+			finish();	//Finishing the activity, onDestroy will be called
+			break;
+		case R.id.startvideo:
+			launchStreamingApp();
+			break;
+		}
+	}
+
+	/**
+	 * If the app is installed, start it. Otherwise, open the Android Market for download
+	 */
+	private void launchStreamingApp() {
+		Intent launchIntent = getPackageManager().getLaunchIntentForPackage(AppConfiguration.DEFAULT_IPCAMERA_APP_PACKAGENAME);
+		if(launchIntent==null) launchIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + AppConfiguration.DEFAULT_IPCAMERA_APP_PACKAGENAME));
+		startActivity( launchIntent );
+	}
+
 }

ArduinoExplorerbotSketch/explorerbot/explorerbot.ino

@@ -37,6 +37,7 @@ const int hBridge2pin = 10;
 #include <Servo.h>
 Servo steeringServo;
 byte gamepadPosition[2];
+byte missedUpdates=0;
 
 void setup(){
   steeringServo.attach(servoPin);  //steering servo to pin 7
@@ -48,8 +49,16 @@ void setup(){
 
 void loop(){
   if(readGamepadPositionFromSerial()){
+    missedUpdates=0;
+    //If data ready, drive motors
     steerTo(gamepadPosition[0]);
     accelerateTo(gamepadPosition[1]);
+  } else {
+    //If data not ready for 5 times (500ms), stop the robot (for security reasons, e.g. the connection may be dropped)
+    missedUpdates++;
+    if(missedUpdates>5){
+      accelerateTo(63);
+    }
   }
   delay(100);
 }
@@ -80,6 +89,6 @@ void accelerateTo(byte speedByte){
     //speedByte = speedByte-64;    
   }
   //analogWrite(hBridgeEnable, speedByte*2);
-  if(speedByte<32 || speedByte>96) digitalWrite(hBridgeEnable, HIGH);
+  if(speedByte<47 || speedByte>79) digitalWrite(hBridgeEnable, HIGH);
   else digitalWrite(hBridgeEnable, LOW);
 }