[Android Studio] hantescu:
Hi!

I have some problems with my bluetooth app. I made the setup for a bluetooth server on a Raspberry Pi and I was able to send data to it with my app, but I don't know how to receive data from the server. The server works properly, I tried with the BlueTerm 2 app and I can receive data from it. Can someone help me to implement the receiver in my app?

My code below:

package com.example.bluetooth1;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.UUID;

import com.example.bluetooth1.R;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
private static final String TAG = "bluetooth1";

Button btnOn, btnOff;

private BluetoothAdapter btAdapter = null;
private BluetoothSocket btSocket = null;
private OutputStream outStream = null;

// SPP UUID service
private static final UUID MY_UUID = UUID.fromString("94f39d29-7d6d-437d-973b-fba39e49d4ee");

// MAC-address of Bluetooth module (you must edit this line)
private static String address = "00:1A:7D:DA:71:14";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

btnOn = (Button) findViewById(R.id.btnOn);
btnOff = (Button) findViewById(R.id.btnOff);

btAdapter = BluetoothAdapter.getDefaultAdapter();
checkBTState();

btnOn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
sendData("esti un prost");
//Toast.makeText(getBaseContext(), "Turn on LED", Toast.LENGTH_SHORT).show();
}
});

btnOff.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
sendData("cel mai prost");
// Toast.makeText(getBaseContext(), "Turn off LED", Toast.LENGTH_SHORT).show();
}
});
}

private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
if(Build.VERSION.SDK_INT >= 10){
try {
final Method m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", new Class[] { UUID.class });
return (BluetoothSocket) m.invoke(device, MY_UUID);
} catch (Exception e) {
Log.e(TAG, "Could not create Insecure RFComm Connection",e);
}
}
return device.createRfcommSocketToServiceRecord(MY_UUID);
}

@Override
public void onResume() {
super.onResume();

// Set up a pointer to the remote node using it's address.
BluetoothDevice device = btAdapter.getRemoteDevice(address);
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e1) {
errorExit("Fatal Error", "In onResume() and socket create failed: " + e1.getMessage() + ".");
}

btAdapter.cancelDiscovery();
try {
btSocket.connect();
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
}
}

try {
outStream = btSocket.getOutputStream();
} catch (IOException e) {
errorExit("Fatal Error", "In onResume() and output stream creation failed:" + e.getMessage() + ".");
}
}

private void checkBTState() {
// Check for Bluetooth support and then check to make sure it is turned on
// Emulator doesn't support Bluetooth and will return null
if(btAdapter==null) {
errorExit("Fatal Error", "Bluetooth not support");
} else {
if (btAdapter.isEnabled()) {
Log.d(TAG, "...Bluetooth ON...");
} else {
//Prompt user to turn on Bluetooth
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
}
}
}

private void errorExit(String title, String message){
Toast.makeText(getBaseContext(), title + " - " + message, Toast.LENGTH_LONG).show();
finish();
}

private void sendData(String message) {
byte[] msgBuffer = message.getBytes();

try {
outStream.write(msgBuffer);
} catch (IOException e) {
String msg = "In onResume() and an exception occurred during write: " + e.getMessage();
if (address.equals("00:00:00:00:00:00"))
msg = msg + ".\n\nUpdate your server address from 00:00:00:00:00:00 to the correct address on line 35 in the java code";
msg = msg + ".\n\nCheck that the SPP UUID: " + MY_UUID.toString() + " exists on server.\n\n";

errorExit("Fatal Error", msg);
}
}
}