I'm making a OBDII Bluetooth Android app and i'm having some issues sending out commands. I've already made a successfully connection between my mobile device and my OBDII adapter, but when I click on another activity, the Bluetooth connection seems to quit?
When you open up the app you'll see a button that says "Connect Device". When you press that, a ListAdapter will show up with paired Bluetooth devices. Then when you have succesfully connected to the device (OBDII Adapter) it will take you to another layout where there is 3 activities that are 3 different powerplatforms for cars. This is where the problem occurs. For now, I just want to be able to read the voltage from the OBDII. But when I click my button getValue inside one of the 3 activities. I get an logcat error. And I think it's because I haven't initiated my BluetoothHandler properly. I have no idea how to do this.
MainActivity:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
Button b1;
BluetoothAdapter mAdapter;
FragmentHostCallback mHost;
BTHandler btHandler;
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case Constants.MESSAGE_STATE_CHANGE:
switch (msg.arg1) {
case BTHandler.STATE_CONNECTED:
//setContentView(R.layout.activity_connected);
Intent intent = new Intent(MainActivity.this, Connected.class);
startActivity(intent);
Toast.makeText(getApplicationContext(), R.string.title_connected_to, Toast.LENGTH_SHORT).show();
Log.v("Log", "Connected");
break;
case BTHandler.STATE_NONE:
Toast.makeText(getApplicationContext(), R.string.title_not_connected, Toast.LENGTH_SHORT).show();
break;
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btHandler = new BTHandler(MainActivity.this, mHandler);
b1 = (Button) findViewById(R.id.connect);
b1.setOnClickListener(this);
mAdapter = BluetoothAdapter.getDefaultAdapter();
//init();
if (mAdapter == null) {
Toast.makeText(getApplicationContext(), R.string.device_not_supported, Toast.LENGTH_LONG).show();
finish();
} else {
if (!mAdapter.isEnabled()) {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, 1);
}
}
//BTHandler btHandler = new BTHandler(MainActivity.this, mHandler);
//btHandler.connect("");
}
public void onClick(View v) {
int id = v.getId();
//String voltage = ("ATRV");
switch (id) {
case R.id.connect:
onConnect(); //Operation
Log.v("Log", "Pressed onClick");
break;
/*case R.id.getValue:
btHandler.write(voltage);
Log.v("Log", "getValue" + voltage);
break;*/
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_CANCELED) {
Toast.makeText(getApplicationContext(), R.string.enable_bluetooth, Toast.LENGTH_SHORT).show();
finish();
}
}
private void onConnect() {
ArrayList deviceStrs = new ArrayList();
final ArrayList<String> devices = new ArrayList();
BluetoothAdapter mAdapter = BluetoothAdapter.getDefaultAdapter();
Set pairedDevices = mAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (Object device : pairedDevices) {
BluetoothDevice bdevice = (BluetoothDevice) device;
deviceStrs.add(bdevice.getName() + "\n" + bdevice.getAddress());
devices.add(bdevice.getAddress());
}
}
// show list
final AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.select_dialog_singlechoice,
deviceStrs.toArray(new String[deviceStrs.size()]));
alertDialog.setSingleChoiceItems(adapter, -1, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
int position = ((AlertDialog) dialog).getListView().getCheckedItemPosition();
String deviceAddress = devices.get(position);
btHandler.connect(deviceAddress);
//btHandler.write();
}
});
alertDialog.setTitle("Paired devices");
alertDialog.show();
}
BTHandler:
public class BTHandler {
public static final int STATE_NONE = 0; // we're doing nothing
public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
public static final int STATE_CONNECTED = 3; // now connected to a remote device
final ArrayList<String> devices = new ArrayList();
private final Handler mHandler;
private BluetoothAdapter mAdapter;
private BluetoothDevice device;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private BluetoothSocket socket;
private String status;
private int mState;
private boolean connectionStatus = false;
public BTHandler(Context context, Handler handler) { // Konstruktor
mAdapter = BluetoothAdapter.getDefaultAdapter();
mHandler = handler;
}
public void write(String s) {
mConnectedThread.sendRawCommand(s);
Log.v("write", "write");
}
/*
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) {
}
}
*/
public void connect(String deviceAddress) {
mConnectThread = new ConnectThread(deviceAddress);
mConnectThread.start();
}
private void guiHandler(int what, int arg1, String obj) {
Message msg = mHandler.obtainMessage();
msg.what = what;
msg.obj = obj;
msg.arg1 = arg1;
msg.sendToTarget();
}
private class ConnectThread extends Thread {
BluetoothSocket tmp = null;
private BluetoothSocket mmSocket;
public ConnectThread(String deviceAddress) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
device = mAdapter.getRemoteDevice(deviceAddress);
BluetoothAdapter mAdapter = BluetoothAdapter.getDefaultAdapter();
BluetoothDevice device = mAdapter.getRemoteDevice(deviceAddress);
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
try {
tmp = device.createRfcommSocketToServiceRecord(uuid);
//socket.connect();
//Log.v("connect", "connect");
} catch (IOException e) {
//e.printStackTrace();
//Log.v("exception", "e");
}
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
mAdapter.cancelDiscovery();
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes;
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
Log.v("connect", "connect");
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
Log.v("close", "close");
} catch (IOException closeException) {
}
guiHandler(Constants.TOAST, Constants.SHORT, "Connection Failed");
return;
}
guiHandler(Constants.CONNECTION_STATUS, Constants.STATE_CONNECTED, "");
mConnectedThread = new ConnectedThread(mmSocket);
mConnectedThread.start();
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private ObdMultiCommand multiCommand;
public ConnectedThread(BluetoothSocket socket) {
connectionStatus = true;
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
try {
//RPMCommand engineRpmCommand = new RPMCommand();
//SpeedCommand speedCommand = new SpeedCommand();
ModuleVoltageCommand voltageCommand = new ModuleVoltageCommand();
while (!Thread.currentThread().isInterrupted()) {
//engineRpmCommand.run(mmInStream, mmOutStream); //(socket.getInputStream(), socket.getOutputStream());
//speedCommand.run(mmInStream, mmOutStream); //(socket.getInputStream(), socket.getOutputStream());
voltageCommand.run(socket.getInputStream(), socket.getOutputStream());
// TODO handle commands result
//Log.d("Log", "RPM: " + engineRpmCommand.getFormattedResult());
//Log.d("Log", "Speed: " + speedCommand.getFormattedResult());
Log.v("Log", "Voltage: " + voltageCommand.getFormattedResult());
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run() {
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
OBDcmds();
// Keep listening to the InputStream until an exception occurs
while (connectionStatus) {
sendMultiCommand();
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
// CALL this to MainActivity
public void sendRawCommand(String command) {
try {
new OdbRawCommand(command);
} catch (Exception e) {
Log.v("sendRawCommand", "e");
}
}
private void OBDcmds() { // execute commands
try {
new EchoOffCommand().run(socket.getInputStream(), socket.getOutputStream());
new LineFeedOffCommand().run(socket.getInputStream(), socket.getOutputStream());
new TimeoutCommand(100).run(socket.getInputStream(), socket.getOutputStream());
new SelectProtocolCommand(ObdProtocols.AUTO).run(socket.getInputStream(), socket.getOutputStream()); //ISO_15765_4_CAN
} catch (Exception e) {
Log.v("OBDcmds", "e");
// handle errors
}
}
/*
// Call this from the main activity to send data to the remote device
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) {
}
}
*/
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
public void sendMultiCommand() {
try {
// RUN some code here
} catch (Exception e) {
}
}
}
}
SPA: One of the power platforms mentioned before.
public class SPA extends AppCompatActivity implements View.OnClickListener {
Button b2;
BTHandler btHandler;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sp);
b2 = (Button) findViewById(R.id.getValue);
b2.setOnClickListener(this);
}
public void onClick(View v) {
int id = v.getId();
String voltage = ("AT RV");
switch (id) {
case R.id.getValue:
btHandler.write(voltage);
Log.v("Log", "getValue" + voltage);
break;
}
}
}
Logcat:
