Android Bluetooth Terminal

The post in my another blogspot show how to "Config Raspberry Pi to use HC-06 Bluetooth Module, as Serial Terminal".

My former post show how "Android communicate with Arduino + HC-06 Bluetooth Module" to link Android with other serial devices via bluetooth. Actually, it can communicate with Raspberry Pi + HC-06 also.

This example I re-code "Android communicate with Arduino + HC-06 Bluetooth Module" to make it work like a serial terminal to log-in Raspberry Pi via bluetooth.

- Prepare on Raspberry Pi 2, to config serial terminal work on 9600 baud, refer "Config Raspberry Pi to use HC-06 Bluetooth Module, as Serial Terminal".
-  The Android and HC-06 have to pair in advance.


Create a new project of Blank Activity in Android Studio,

layout/content_main.xml, its the main terminal screen.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 
 
 
 android_layout_width="match_parent"
 android_layout_height="match_parent"
 android_padding="5dp"
 android_orientation="vertical"
 app_layout_behavior="@string/appbar_scrolling_view_behavior"
 tools_showIn="@layout/activity_main"
 tools_context=".MainActivity">

 <TextView
 android_layout_width="wrap_content"
 android_layout_height="wrap_content"
 android_layout_gravity="center_horizontal"
 android_autoLink="web"
 android_text="http://android-er.blogspot.com/"
 android_textStyle="bold" />

 <TextView
 android_id="@+id/body"
 android_layout_width="match_parent"
 android_layout_height="match_parent"
 android_textColor="@android:color/white"
 android_background="@android:color/black"
 android_typeface="monospace"
 android_gravity="bottom"/>

</LinearLayout>

Edit layout/activity_main.xml, just to change the icon of the FloatingActionButton.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
 
 
  android_layout_width="match_parent"
 android_layout_height="match_parent" android_fitsSystemWindows="true"
 tools_context=".MainActivity">

 <android.support.design.widget.AppBarLayout android_layout_height="wrap_content"
 android_layout_width="match_parent" android_theme="@style/AppTheme.AppBarOverlay">

 <android.support.v7.widget.Toolbar android_id="@+id/toolbar"
 android_layout_width="match_parent" android_layout_height="?attr/actionBarSize"
 android_background="?attr/colorPrimary" app_popupTheme="@style/AppTheme.PopupOverlay" />

 </android.support.design.widget.AppBarLayout>

 <include layout="@layout/content_main" />

 <android.support.design.widget.FloatingActionButton android_id="@+id/fab"
 android_layout_width="wrap_content" android_layout_height="wrap_content"
 android_layout_gravity="bottom|end" android_layout_margin="@dimen/fab_margin"
 android_src="@android:drawable/ic_menu_edit" />

</android.support.design.widget.CoordinatorLayout>

Create layout/setting_layout.xml, the layout of SettingDialog (OptionsMenu -> Setting), to list paired bluetooth to connect.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 
 android_orientation="vertical"
 android_layout_width="match_parent"
 android_layout_height="match_parent">

 <ListView
 android_id="@+id/pairedlist"
 android_layout_width="match_parent"
 android_layout_height="match_parent"/>

</LinearLayout>

Create layout/typing_layout.xml, the layout of CmdLineDialog (open once FloatingActionButton is clicked), for user to enter command.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 
 android_orientation="vertical"
 android_layout_width="match_parent"
 android_layout_height="match_parent">


 <LinearLayout
 android_layout_width="match_parent"
 android_layout_height="wrap_content"
 android_orientation="horizontal">
 <EditText
 android_id="@+id/cmdline"
 android_layout_weight="1"
 android_layout_width="0dp"
 android_layout_height="wrap_content" />

 <ImageView
 android_id="@+id/clearcmd"
 android_layout_width="wrap_content"
 android_src="@android:drawable/ic_menu_close_clear_cancel"
 android_layout_height="wrap_content" />
 </LinearLayout>
 <LinearLayout
 android_layout_width="match_parent"
 android_layout_height="match_parent"
 android_orientation="horizontal">
 <Button
 android_id="@+id/clear"
 android_layout_width="0dp"
 android_layout_height="wrap_content"
 android_layout_weight="1"
 android_text="Clear"/>
 <Button
 android_id="@+id/dismiss"
 android_layout_width="0dp"
 android_layout_height="wrap_content"
 android_layout_weight="1"
 android_text="Dismiss"/>
 <Button
 android_id="@+id/enter"
 android_layout_width="0dp"
 android_layout_height="wrap_content"
 android_layout_weight="1"
 android_text="Enter"/>
 </LinearLayout>

</LinearLayout>

MainActivity.java
[remark: a bug here, refer Update@2015-11-11on bottom of this post.]

package com.blogspot.android_er.androidbluetoothterminal;

import android.app.Activity;
import android.app.Dialog;
import android.app.DialogFragment;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.method.ScrollingMovementMethod;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {

 private static final int REQUEST_ENABLE_BT = 1;

 BluetoothAdapter bluetoothAdapter;

 ArrayList<BluetoothDevice> pairedDeviceArrayList;
 ArrayAdapter<BluetoothDevice> pairedDeviceAdapter;
 private static UUID myUUID;
 private final String UUID_STRING_WELL_KNOWN_SPP =
 "00001101-0000-1000-8000-00805F9B34FB";

 ThreadConnectBTdevice myThreadConnectBTdevice;
 ThreadConnected myThreadConnected;

 static TextView body;
 FloatingActionButton fab;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
 setSupportActionBar(toolbar);

 body = (TextView)findViewById(R.id.body);
 body.setMovementMethod(new ScrollingMovementMethod());

 fab = (FloatingActionButton) findViewById(R.id.fab);
 fab.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View view) {
 showCmdLineDialog();
 }
 });

 fab.setEnabled(false);
 fab.setVisibility(FloatingActionButton.GONE);

 if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)){
 Toast.makeText(this,
 "FEATURE_BLUETOOTH NOT support",
 Toast.LENGTH_LONG).show();
 finish();
 return;
 }

 //using the well-known SPP UUID
 myUUID = UUID.fromString(UUID_STRING_WELL_KNOWN_SPP);

 bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
 if (bluetoothAdapter == null) {
 Toast.makeText(this,
 "Bluetooth is not supported on this hardware platform",
 Toast.LENGTH_LONG).show();
 finish();
 return;
 }

 String strInfo = bluetoothAdapter.getName() + " " +
 bluetoothAdapter.getAddress();
 Toast.makeText(getApplicationContext(), strInfo, Toast.LENGTH_LONG).show();

 }

 @Override
 protected void onStart() {
 super.onStart();

 //Turn ON BlueTooth if it is OFF
 if (!bluetoothAdapter.isEnabled()) {
 Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
 }
 }

 @Override
 protected void onDestroy() {
 super.onDestroy();
 closeThreads();
 }

 private void closeThreads(){
 if(myThreadConnectBTdevice!=null){
 myThreadConnectBTdevice.cancel();
 myThreadConnectBTdevice = null;
 }

 if(myThreadConnected!=null){
 myThreadConnected.cancel();
 myThreadConnected = null;
 }
 }

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 if(requestCode==REQUEST_ENABLE_BT){
 if(resultCode == Activity.RESULT_OK){

 }else{
 Toast.makeText(this,
 "BlueTooth NOT enabled",
 Toast.LENGTH_SHORT).show();
 finish();
 }
 }
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
 // Inflate the menu; this adds items to the action bar if it is present.
 getMenuInflater().inflate(R.menu.menu_main, menu);
 return true;
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
 // Handle action bar item clicks here. The action bar will
 // automatically handle clicks on the Home/Up button, so long
 // as you specify a parent activity in AndroidManifest.xml.
 int id = item.getItemId();

 //noinspection SimplifiableIfStatement
 if (id == R.id.action_settings) {
 closeThreads();
 fab.setEnabled(false);
 fab.setVisibility(FloatingActionButton.GONE);
 body.setText("");
 showSettingDialog();
 return true;
 }

 return super.onOptionsItemSelected(item);
 }

 void showSettingDialog() {
 FragmentTransaction ft = getFragmentManager().beginTransaction();
 Fragment prev = getFragmentManager().findFragmentByTag("dialog");
 if (prev != null) {
 ft.remove(prev);
 }
 ft.addToBackStack(null);

 DialogFragment newFragment = SettingDialogFragment.newInstance(MainActivity.this);
 newFragment.show(ft, "dialog");

 }

 void showCmdLineDialog() {

 if(myThreadConnected == null){
 Toast.makeText(MainActivity.this,
 "myThreadConnected == null",
 Toast.LENGTH_LONG).show();
 return;
 }

 FragmentTransaction ft = getFragmentManager().beginTransaction();
 Fragment prev = getFragmentManager().findFragmentByTag("cmdline");
 if (prev != null) {
 ft.remove(prev);
 }
 ft.addToBackStack(null);

 DialogFragment newFragment = TypingDialogFragment.newInstance(MainActivity.this, myThreadConnected);
 newFragment.show(ft, "cmdline");

 }

 private void setup(ListView lv, final Dialog dialog) {
 Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
 if (pairedDevices.size() > 0) {
 pairedDeviceArrayList = new ArrayList<BluetoothDevice>();

 for (BluetoothDevice device : pairedDevices) {
 pairedDeviceArrayList.add(device);
 }

 pairedDeviceAdapter = new ArrayAdapter<BluetoothDevice>(this,
 android.R.layout.simple_list_item_1, pairedDeviceArrayList);
 lv.setAdapter(pairedDeviceAdapter);

 lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {

 @Override
 public void onItemClick(AdapterView<?> parent, View view,
 int position, long id) {
 BluetoothDevice device =
 (BluetoothDevice) parent.getItemAtPosition(position);
 Toast.makeText(MainActivity.this,
 "Name: " + device.getName() + " "
 + "Address: " + device.getAddress() + " "
 + "BondState: " + device.getBondState() + " "
 + "BluetoothClass: " + device.getBluetoothClass() + " "
 + "Class: " + device.getClass(),
 Toast.LENGTH_LONG).show();

 Toast.makeText(MainActivity.this, "start ThreadConnectBTdevice", Toast.LENGTH_LONG).show();
 myThreadConnectBTdevice = new ThreadConnectBTdevice(device, dialog);
 myThreadConnectBTdevice.start();
 }
 });
 }
 }

 public static class SettingDialogFragment extends DialogFragment {

 ListView listViewPairedDevice;
 static MainActivity parentActivity;

 static SettingDialogFragment newInstance(MainActivity parent){
 parentActivity = parent;
 SettingDialogFragment f = new SettingDialogFragment();
 return f;
 }

 @Nullable
 @Override
 public View onCreateView(LayoutInflater inflater,
 ViewGroup container, Bundle savedInstanceState) {
 getDialog().setTitle("Setting");
 getDialog().setCanceledOnTouchOutside(false);
 View settingDialogView = inflater.inflate(R.layout.setting_layout, container, false);

 listViewPairedDevice = (ListView)settingDialogView.findViewById(R.id.pairedlist);

 parentActivity.setup(listViewPairedDevice, getDialog());

 return settingDialogView;
 }
 }

 public static class TypingDialogFragment extends DialogFragment {

 EditText cmdLine;
 static MainActivity parentActivity;
 static ThreadConnected cmdThreadConnected;

 static TypingDialogFragment newInstance(MainActivity parent, ThreadConnected thread){
 parentActivity = parent;
 cmdThreadConnected = thread;
 TypingDialogFragment f = new TypingDialogFragment();
 return f;
 }

 @Nullable
 @Override
 public View onCreateView(LayoutInflater inflater,
 ViewGroup container, Bundle savedInstanceState) {
 getDialog().setTitle("Cmd Line");
 getDialog().setCanceledOnTouchOutside(false);
 View typingDialogView = inflater.inflate(R.layout.typing_layout, container, false);

 cmdLine = (EditText)typingDialogView.findViewById(R.id.cmdline);

 ImageView imgCleaarCmd = (ImageView)typingDialogView.findViewById(R.id.clearcmd);
 imgCleaarCmd.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 cmdLine.setText("");
 }
 });

 Button btnEnter = (Button)typingDialogView.findViewById(R.id.enter);
 btnEnter.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(cmdThreadConnected!=null){
 byte[] bytesToSend = cmdLine.getText().toString().getBytes();
 cmdThreadConnected.write(bytesToSend);
 byte[] NewLine = " ".getBytes();
 cmdThreadConnected.write(NewLine);
 }
 }
 });

 Button btnDismiss = (Button)typingDialogView.findViewById(R.id.dismiss);
 btnDismiss.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 dismiss();
 }
 });

 Button btnClear = (Button)typingDialogView.findViewById(R.id.clear);
 btnClear.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 body.setText("");
 }
 });

 return typingDialogView;
 }
 }

 //Called in ThreadConnectBTdevice once connect successed
 //to start ThreadConnected
 private void startThreadConnected(BluetoothSocket socket){

 myThreadConnected = new ThreadConnected(socket);
 myThreadConnected.start();
 }

 /*
 ThreadConnectBTdevice:
 Background Thread to handle BlueTooth connecting
 */
 private class ThreadConnectBTdevice extends Thread {

 private BluetoothSocket bluetoothSocket = null;
 private final BluetoothDevice bluetoothDevice;
 Dialog dialog;

 private ThreadConnectBTdevice(BluetoothDevice device, Dialog dialog) {
 this.dialog = dialog;
 bluetoothDevice = device;

 try {
 bluetoothSocket = device.createRfcommSocketToServiceRecord(myUUID);
 Toast.makeText(MainActivity.this,
 "bluetoothSocket: " + bluetoothSocket,
 Toast.LENGTH_SHORT).show();
 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 }

 @Override
 public void run() {
 boolean success = false;
 try {
 bluetoothSocket.connect();
 success = true;
 } catch (IOException e) {
 e.printStackTrace();

 final String eMessage = e.getMessage();
 runOnUiThread(new Runnable() {

 @Override
 public void run() {
 Toast.makeText(MainActivity.this,
 "something wrong bluetoothSocket.connect(): " + eMessage,
 Toast.LENGTH_SHORT).show();
 }
 });

 try {
 bluetoothSocket.close();
 } catch (IOException e1) {
 // TODO Auto-generated catch block
 e1.printStackTrace();
 }
 }

 if(success){
 //connect successful
 final String msgconnected = "connect successful: "
 + "BluetoothSocket: " + bluetoothSocket + " "
 + "BluetoothDevice: " + bluetoothDevice;

 runOnUiThread(new Runnable() {

 @Override
 public void run() {
 fab.setEnabled(true);
 fab.setVisibility(FloatingActionButton.VISIBLE);
 body.setText("");
 Toast.makeText(MainActivity.this, msgconnected, Toast.LENGTH_LONG).show();
 dialog.dismiss();
 }
 });

 startThreadConnected(bluetoothSocket);

 }else{
 //fail
 }
 }

 public void cancel() {

 Toast.makeText(getApplicationContext(),
 "close bluetoothSocket",
 Toast.LENGTH_LONG).show();
 try {
 bluetoothSocket.close();
 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }

 }

 }

 /*
 ThreadConnected:
 Background Thread to handle Bluetooth data communication
 after connected
 */
 private class ThreadConnected extends Thread {
 private final BluetoothSocket connectedBluetoothSocket;
 private final InputStream connectedInputStream;
 private final OutputStream connectedOutputStream;

 boolean running;

 public ThreadConnected(BluetoothSocket socket) {
 connectedBluetoothSocket = socket;
 InputStream in = null;
 OutputStream out = null;
 running = true;
 try {
 in = socket.getInputStream();
 out = socket.getOutputStream();
 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }

 connectedInputStream = in;
 connectedOutputStream = out;
 }

 @Override
 public void run() {
 byte[] buffer = new byte[1024];
 int bytes;

 String strRx = "";

 while (running) {
 try {
 bytes = connectedInputStream.read(buffer);
 final String strReceived = new String(buffer, 0, bytes);
 final String strByteCnt = String.valueOf(bytes) + " bytes received. ";

 runOnUiThread(new Runnable(){

 @Override
 public void run() {
 body.append(strReceived);
 }});

 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();

 final String msgConnectionLost = "Connection lost: "
 + e.getMessage();
 runOnUiThread(new Runnable(){

 @Override
 public void run() {
 Toast.makeText(MainActivity.this, msgConnectionLost, Toast.LENGTH_LONG).show();

 }});
 }
 }
 }

 public void write(byte[] buffer) {
 try {
 connectedOutputStream.write(buffer);
 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 }

 public void cancel() {
 running = false;
 try {
 connectedBluetoothSocket.close();
 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 }
 }

}

uses-permission of "android.permission.BLUETOOTH" is needed in src/main/AndroidManifest.xml.

<?xml version="1.0" encoding="utf-8"?>
<manifest 
 package="com.blogspot.android_er.androidbluetoothterminal" >

 <uses-permission android_name="android.permission.BLUETOOTH"/>
 <application
 android_allowBackup="true"
 android_icon="@mipmap/ic_launcher"
 android_label="@string/app_name"
 android_supportsRtl="true"
 android_theme="@style/AppTheme" >
 <activity
 android_name=".MainActivity"
 android_label="@string/app_name"
 android_theme="@style/AppTheme.NoActionBar" >
 <intent-filter>
 <action android_name="android.intent.action.MAIN" />

 <category android_name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 </application>

</manifest>

Download the files (Android Studio Format) .

Download APK .

---

Update@2015-11-11:
In the above code of MainActivity.java, in run() of ThreadConnected, if Connection lost (such as Raspberry Pi or HC-06 power OFF), the thread will still keep running.

So have to cancel the thread and disable the FloatingActionButton. Modify run() of ThreadConnected.

 @Override
 public void run() {
 byte[] buffer = new byte[1024];
 int bytes;

 String strRx = "";

 while (running) {
 try {
 bytes = connectedInputStream.read(buffer);
 final String strReceived = new String(buffer, 0, bytes);
 final String strByteCnt = String.valueOf(bytes) + " bytes received. ";

 runOnUiThread(new Runnable(){

 @Override
 public void run() {
 body.append(strReceived);
 }});

 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();

 cancel();

 final String msgConnectionLost = "Connection lost: "
 + e.getMessage();
 runOnUiThread(new Runnable(){

 @Override
 public void run() {
 Toast.makeText(MainActivity.this, msgConnectionLost, Toast.LENGTH_LONG).show();

 fab.setEnabled(false);
 fab.setVisibility(FloatingActionButton.GONE);

 }});
 }
 }
 }

---

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Install Android Studio 2 0 Preview on Ubuntu Linux parallel with existing installed Android Studio

Android Studio 2.0 Preview is available to download in Canary Channel now. This video show how to download and run in Ubuntu (Ubuntu-GNOME 15.10 on VirtualBox/Windows 10), in parallel with existing installed Android Studio 1.5.


(reference: Android Developers Blog)

Related:
- Download and run Android Studio 2.0 Preview on Windows 10

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