Question

我是Android编程的新手，但我设法解决了以下问题。

我有此设置：

具有HC-05蓝牙模块和中继板模块的Arduino。
Android手机。

我在Android上制作了一个应用，该应用通过蓝牙向Arduino发送了一些字符。这部分工作正常。

与此同时，Arduino以每500毫秒的间隔发送回“ A”字符。

在应用程序中，我要检查是否接收到字符，然后更改TextView的文本。

我不知道为什么，处理程序中的if (readMessage.equals("A")无法正常工作（它不会在ID为“ readBuffer”的TextView上将文本更改为“ work”），而{{ 1}}工作正常。

Android代码

mReadBuffer.setText(readMessage)

部分Arduino代码

public class MainActivity extends AppCompatActivity {
private static final UUID BTMODULEUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); // "random" unique identifier
// #defines for identifying shared types between calling functions
private final static int REQUEST_ENABLE_BT = 1; // used to identify adding bluetooth names
private final static int MESSAGE_READ = 2; // used in bluetooth handler to identify message update
private final static int CONNECTING_STATUS = 3; // used in bluetooth handler to identify message status
private final String TAG = MainActivity.class.getSimpleName();
private TextView mBluetoothStatus;
private TextView mReadBuffer;
private Button mScanBtn;
private Button mOffBtn;
private Button mListPairedDevicesBtn;
private Button mDiscoverBtn;
private BluetoothAdapter mBTAdapter;
private Set<BluetoothDevice> mPairedDevices;
private ArrayAdapter<String> mBTArrayAdapter;
private ListView mDevicesListView;
private ToggleButton Sw2;
private ToggleButton Sw1;
private Handler mHandler; // Our main handler that will receive callback notifications
private ConnectedThread mConnectedThread; // bluetooth background worker thread to send and receive data
private BluetoothSocket mBTSocket = null;
public static final byte SW2ON = (byte)65;
public static final byte SW2OFF = (byte)78;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mBluetoothStatus = (TextView) findViewById(R.id.readBuffer);
    mReadBuffer = (TextView) findViewById(R.id.rx);
    mScanBtn = (Button) findViewById(R.id.btcon);
    mOffBtn = (Button) findViewById(R.id.btdiscon);
    mDiscoverBtn = (Button) findViewById(R.id.discover);
    mListPairedDevicesBtn = (Button) findViewById(R.id.paired);
    Sw1 = (ToggleButton) findViewById(R.id.sw1);
    Sw2 = (ToggleButton) findViewById(R.id.sw2);
    mBTArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1);
    mBTAdapter = BluetoothAdapter.getDefaultAdapter(); // get a handle on the bluetooth radio

    mDevicesListView = (ListView) findViewById(R.id.devicesListView);
    mDevicesListView.setAdapter(mBTArrayAdapter); // assign model to view
    mDevicesListView.setOnItemClickListener(mDeviceClickListener);
   // if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
   //     ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1);

    mHandler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            if (msg.what == MESSAGE_READ) {
                String readMessage = null;
                try {
                    readMessage = new String((byte[]) msg.obj, "UTF-8");
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

                mReadBuffer.setText(readMessage);
                if (readMessage.equals("A") ){
                    mBluetoothStatus.setText("works ");
                    Sw2.setChecked(true);
                }

            }

            if (msg.what == CONNECTING_STATUS) {
                if (msg.arg1 == 1)
                    mBluetoothStatus.setText("Connected to Device: " + (String) (msg.obj));
                else
                    mBluetoothStatus.setText("Connection Failed");
            }
        }
    };

    if (mBTArrayAdapter == null) {
        // Device does not support Bluetooth
        mBluetoothStatus.setText("Status: Bluetooth not found");
        Toast.makeText(getApplicationContext(), "Bluetooth device not found!", Toast.LENGTH_SHORT).show();
    } else {

        Sw1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mConnectedThread != null) //First check to make sure thread created
                    mConnectedThread.write("1");
            }
        });

        Sw2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked){
                    if (mConnectedThread != null)
                        mConnectedThread.write("A");
                }
                else
                {
                    if (mConnectedThread != null)
                        mConnectedThread.write("N");
                }
            }
        });
        Sw1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked){
                    if (mConnectedThread != null)
                        mConnectedThread.write("B");
                }
                else
                {
                    if (mConnectedThread != null)
                        mConnectedThread.write("O");
                }
            }
        });

        mScanBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                bluetoothOn(v);
            }
        });

        mOffBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                bluetoothOff(v);
            }
        });

        mListPairedDevicesBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                listPairedDevices(v);
            }
        });

        mDiscoverBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                discover(v);
            }
        });
    }
}

private void bluetoothOn(View view) {
    if (!mBTAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
        mBluetoothStatus.setText("Bluetooth enabled");
        Toast.makeText(getApplicationContext(), "Bluetooth turned on", Toast.LENGTH_SHORT).show();

    } else {
        Toast.makeText(getApplicationContext(), "Bluetooth is already on", Toast.LENGTH_SHORT).show();
    }
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent Data){
    // Check which request we're responding to
    if (requestCode == REQUEST_ENABLE_BT) {
        // Make sure the request was successful
        if (resultCode == RESULT_OK) {
            // The user picked a contact.
            // The Intent's data Uri identifies which contact was selected.
            mBluetoothStatus.setText("Enabled");
        }
        else
            mBluetoothStatus.setText("Disabled");
    }
}
private void bluetoothOff(View view){
    mBTAdapter.disable(); // turn off
    mBluetoothStatus.setText("Bluetooth disabled");
    Toast.makeText(getApplicationContext(),"Bluetooth turned Off", Toast.LENGTH_SHORT).show();
}
private void discover(View view){
    // Check if the device is already discovering
    if(mBTAdapter.isDiscovering()){
        mBTAdapter.cancelDiscovery();
        Toast.makeText(getApplicationContext(),"Discovery stopped",Toast.LENGTH_SHORT).show();
    }
    else{
        if(mBTAdapter.isEnabled()) {
            mBTArrayAdapter.clear(); // clear items
            mBTAdapter.startDiscovery();
            Toast.makeText(getApplicationContext(), "Discovery started", Toast.LENGTH_SHORT).show();
            registerReceiver(blReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
        }
        else{
            Toast.makeText(getApplicationContext(), "Bluetooth not on", Toast.LENGTH_SHORT).show();
        }
    }
}
final BroadcastReceiver blReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if(BluetoothDevice.ACTION_FOUND.equals(action)){
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            // add the name to the list
            mBTArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            mBTArrayAdapter.notifyDataSetChanged();
        }
    }
};
private void listPairedDevices(View view){
    mPairedDevices = mBTAdapter.getBondedDevices();
    if(mBTAdapter.isEnabled()) {
        // put it's one to the adapter
        for (BluetoothDevice device : mPairedDevices)
            mBTArrayAdapter.add(device.getName() + "\n" + device.getAddress());

        Toast.makeText(getApplicationContext(), "Show Paired Devices", Toast.LENGTH_SHORT).show();
    }
    else
        Toast.makeText(getApplicationContext(), "Bluetooth not on", Toast.LENGTH_SHORT).show();
}
private AdapterView.OnItemClickListener mDeviceClickListener = new AdapterView.OnItemClickListener() {
    public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {

        if(!mBTAdapter.isEnabled()) {
            Toast.makeText(getBaseContext(), "Bluetooth not on", Toast.LENGTH_SHORT).show();
            return;
        }

        mBluetoothStatus.setText("Connecting...");
        // Get the device MAC address, which is the last 17 chars in the View
        String info = ((TextView) v).getText().toString();
        final String address = info.substring(info.length() - 17);
        final String name = info.substring(0,info.length() - 17);

        // Spawn a new thread to avoid blocking the GUI one
        new Thread()
        {
            public void run() {
                boolean fail = false;

                BluetoothDevice device = mBTAdapter.getRemoteDevice(address);

                try {
                    mBTSocket = createBluetoothSocket(device);
                } catch (IOException e) {
                    fail = true;
                    Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_SHORT).show();
                }
                // Establish the Bluetooth socket connection.
                try {
                    mBTSocket.connect();
                } catch (IOException e) {
                    try {
                        fail = true;
                        mBTSocket.close();
                        mHandler.obtainMessage(CONNECTING_STATUS, -1, -1)
                                .sendToTarget();
                    } catch (IOException e2) {
                        //insert code to deal with this
                        Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_SHORT).show();
                    }
                }
                if(fail == false) {
                    mConnectedThread = new ConnectedThread(mBTSocket);
                    mConnectedThread.start();

                    mHandler.obtainMessage(CONNECTING_STATUS, 1, -1, name)
                            .sendToTarget();
                }
            }
        }.start();
    }
};
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
    try {
        final Method m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", UUID.class);
        return (BluetoothSocket) m.invoke(device, BTMODULEUUID);
    } catch (Exception e) {
        Log.e(TAG, "Could not create Insecure RFComm Connection",e);
    }
    return  device.createRfcommSocketToServiceRecord(BTMODULEUUID);
}

private class ConnectedThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;

    public ConnectedThread(BluetoothSocket socket) {
        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;

        // Get the input and output streams, using temp objects because
        // member streams are final
        try {
            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();
        } catch (IOException e) { }

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }

    public void run() {
        byte[] buffer = new byte[1024];  // buffer store for the stream
        int bytes; // bytes returned from read()
        // Keep listening to the InputStream until an exception occurs
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.available();
                if(bytes != 0) {
                    buffer = new byte[1024];
                    SystemClock.sleep(100); //pause and wait for rest of data. Adjust this depending on your sending speed.
                    bytes = mmInStream.available(); // how many bytes are ready to be read?
                    bytes = mmInStream.read(buffer, 0, bytes); // record how many bytes we actually read
                    mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
                            .sendToTarget(); // Send the obtained bytes to the UI activity
                }
            } catch (IOException e) {
                e.printStackTrace();

                break;
            }
        }
    }

    /* Call this from the main activity to send data to the remote device */
    public void write(String input) {
        byte[] bytes = input.getBytes();           //converts entered String into 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) { }
    }
}

}

使用手机上的Bluetooth终端显示已收到“ A”字符。

蓝牙终端：

有人可以告诉我我在做什么错吗？

通过蓝牙模块与Arduino通信

0 个答案: