我正在尝试制作一款可以通过蓝牙从arduino发送和接收数据的应用。我发送数据的部分非常简单，所以我设法做到了。我在接收数据时遇到了困难。
我的程序有2个布局。首先是一个带有CONNECT按钮的布局和一些改变布局的按钮。这是代码：
Public class MainActivity extends AppCompatActivity {
ImageButton test, manual,connect;
Button back;
private BluetoothAdapter mbluetoothAdapter;
protected AlertDialog.Builder builder;
ConnectThread mBluetooth = new ConnectThread();
String mBluetoothName = "";
String mBluetoothAdress = "";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final Context context = this;
//final LayoutInflater factory = getLayoutInflater();
//final View textEntryView = factory.inflate(R.layout.activity_main);
builder = new AlertDialog.Builder(this);
mbluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
connect = (ImageButton) findViewById(R.id.connect);
test = (ImageButton) findViewById(R.id.test);
manual = (ImageButton) findViewById(R.id.manual);
test.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(context,SecondActivity.class );
context.startActivity(intent);
}
});
manual.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(context,SecondActivity.class );
context.startActivity(intent);
}
});
connect.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!mbluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivity(enableBtIntent);
} else {
if (!mBluetooth.mBluetoothAddress.equals("")) {//if another connection is already exits then close it first
stopAllActivities();
} else {
try {
Intent serverIntent = new Intent(MainActivity.this, DeviceListActivity.class);
startActivityForResult(serverIntent, Helper.REQUEST_CONNECT_DEVICE);
} catch (Exception e) {
showToast(getString(R.string.errorOccured) + ": " + e.getMessage());
e.printStackTrace();
}
}
}
}
});
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case Helper.REQUEST_CONNECT_DEVICE:
if (resultCode == Activity.RESULT_OK) {
mBluetoothName = data.getExtras().getString(Helper.EXTRA_BLUETOOTH_NAME);
mBluetoothAdress = data.getExtras().getString(Helper.EXTRA_BLUETOOTH_ADDRESS);
// setBluetoothInfo();
showToast(R.string.connectedDevice + mBluetoothName);
if (!mBluetoothAdress.equals("")) {
if (!mBluetooth.connect(mBluetoothAdress)){
}
}
}
break;
}
}
SecondActivity包含此应用程序的主要用途：发送和接收数据。这就是它的样子：
public class SecondActivity extends AppCompatActivity {
final Context context = this;
Button back;
ImageButton btnup, btndown, btnright, btnleft;
ConnectThread mBluetooth = new ConnectThread();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnup = (ImageButton) findViewById(R.id.btnup);
btndown = (ImageButton) findViewById(R.id.btndown);
btnleft = (ImageButton) findViewById(R.id.btnleft);
btnright = (ImageButton) findViewById(R.id.btnright);
final TextView direction = (TextView) findViewById(R.id.text_direction);
final TextView steering = (TextView) findViewById(R.id.steering_direction);
final TextView speed = (TextView) findViewById(R.id.speed);
final TextView battery = (TextView) findViewById(R.id.batery);
final Chronometer chronometer = (Chronometer) findViewById(R.id.chronometer);
btndown.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
mBluetooth.write("2");
direction.setText(R.string.Backwards);
} else if (event.getAction() == MotionEvent.ACTION_UP) {
mBluetooth.write("x");
direction.setText(R.string.blank);
}
return false;
}
});
注意：我没有发布整个代码，因为我有更多的按钮，其代码与上面的代码完全相同。
对于蓝牙连接，我有2个单独的类，一个名为ConnectThread：
public class ConnectThread {
BluetoothAdapter mBluetoothAdapter = null;
BluetoothSocket mSocket = null;
OutputStream mOutStream = null;
InputStream mInStream=null;
String mBluetoothAddress = "";
public boolean connect(String bluetoothAddress) {
if (!mBluetoothAddress.equals(bluetoothAddress) && !mBluetoothAddress.equals("")) {
close();
}
mBluetoothAddress = bluetoothAddress;
if (mBluetoothAdapter == null) {
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
}
if (mBluetoothAdapter == null) {
return false;
}
if (!mBluetoothAdapter.isEnabled()) {
return false;
}
try {
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(mBluetoothAddress);
if (mSocket == null) {
mSocket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
mSocket.connect();
}
} catch (IOException e) {
mSocket = null;
e.printStackTrace();
return false;
}
try {
mOutStream = mSocket.getOutputStream();
} catch (IOException e) {
mOutStream = null;
e.printStackTrace();
return false;
}
return true;
}
public boolean check() {
if (mBluetoothAdapter == null) {
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
}
if (mBluetoothAdapter == null) {
return false;
}
if (!mBluetoothAdapter.isEnabled()) {
return false;
}
if (!mSocket.isConnected()) {
return false;
}
return true;
}
public boolean close() {
try {
if (mOutStream != null) {
mOutStream.close();
}
if (mSocket != null) {
mSocket.close();
}
} catch (IOException e) {
e.printStackTrace();
return false;
}
mOutStream = null;
mSocket = null;
return true;
}
public boolean write(String strData) {
byte[] buffer = strData.getBytes();
try {
if (mOutStream != null && mBluetoothAdapter.getState() == BluetoothAdapter.STATE_ON) {
mOutStream.write(buffer);
}
else {
return false;
}
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
}
另一个DeviceListActivity：
public class DeviceListActivity extends Activity {
private BluetoothAdapter mBtAdapter;
private ArrayAdapter<String> mPairedDevicesArrayAdapter;
private ArrayAdapter<String> mNewDevicesArrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Setup the window
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.device_list);
// Set result CANCELED incase the user backs out
setResult(Activity.RESULT_CANCELED);
// Initialize the button to perform device discovery
Button scanButton = (Button) findViewById(R.id.button_scan);
scanButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (mBtAdapter == null)
return;
doDiscovery();
v.setVisibility(View.GONE);
}
});
// Initialize array adapters. One for already paired devices and
// one for newly discovered devices
mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
// Find and set up the ListView for paired devices
ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
pairedListView.setAdapter(mPairedDevicesArrayAdapter);
pairedListView.setOnItemClickListener(mDeviceClickListener);
// Find and set up the ListView for newly discovered devices
ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
newDevicesListView.setOnItemClickListener(mDeviceClickListener);
// Register for broadcasts when a device is discovered
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
// Register for broadcasts when discovery has finished
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(mReceiver, filter);
// Get the local Bluetooth adapter
mBtAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBtAdapter == null) {
mPairedDevicesArrayAdapter.add("DUMMY\n00:00:00:00:00:00");
return;
}
// Get a set of currently paired devices
Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
// If there are paired devices, add each one to the ArrayAdapter
if (pairedDevices.size() > 0) {
findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
for (BluetoothDevice device : pairedDevices) {
mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
} else {
String noDevices = getResources().getText(R.string.none_paired).toString();
mPairedDevicesArrayAdapter.add(noDevices);
}
}
@Override
protected void onDestroy() {
super.onDestroy();
// Make sure we're not doing discovery anymore
if (mBtAdapter != null)
mBtAdapter.cancelDiscovery();
// Unregister broadcast listeners
this.unregisterReceiver(mReceiver);
}
/**
* Start device discover with the BluetoothAdapter
*/
private void doDiscovery() {
if (mBtAdapter == null)
return;
// Indicate scanning in the title
setProgressBarIndeterminateVisibility(true);
setTitle(R.string.scanning);
// Turn on sub-title for new devices
findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);
// If we're already discovering, stop it
if (mBtAdapter.isDiscovering()) {
mBtAdapter.cancelDiscovery();
}
// Request discover from BluetoothAdapter
mBtAdapter.startDiscovery();
}
// The on-click listener for all devices in the ListViews
private AdapterView.OnItemClickListener mDeviceClickListener = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
if (mBtAdapter != null) {
// Cancel discovery because it's costly and we're about to connect
mBtAdapter.cancelDiscovery();
}
// Get the device MAC address, which is the last 17 chars in the View
String info = ((TextView) v).getText().toString();
String name = info.substring(0, info.length() - 18);
String address = info.substring(info.length() - 17);
// Create the result Intent and include the MAC address
Intent intent = new Intent();
intent.putExtra(Helper.EXTRA_BLUETOOTH_ADDRESS, address);
intent.putExtra(Helper.EXTRA_BLUETOOTH_NAME, name);
// Set result and finish this Activity
setResult(Activity.RESULT_OK, intent);
finish();
}
};
// The BroadcastReceiver that listens for discovered devices and
// changes the title when discovery is finished
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// When discovery finds a device
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// If it's already paired, skip it, because it's been listed already
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
for (int i = 0; i < mNewDevicesArrayAdapter.getCount(); i++) {
if (mNewDevicesArrayAdapter.getItem(i).equals(device.getName() + "\n" + device.getAddress())) {
return;
}
}
mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
// When discovery is finished, change the Activity title
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
setProgressBarIndeterminateVisibility(false);
setTitle(R.string.select_device);
if (mNewDevicesArrayAdapter.getCount() == 0) {
String noDevices = getResources().getText(R.string.none_found).toString();
mNewDevicesArrayAdapter.add(noDevices);
}
}
}
};
}
我想用从arduino收到的数据更新两个TextView。数据看起来像＃first_data，second_data *，其中＃是数据系列的开头，*是结束。如果您能帮助我提供一些建议/代码如何做到这一点，我将不胜感激。我对java很新，我还不完全理解一切是如何工作的。
答案 0 :(得分：0)
获得蓝牙套接字后，您可以使用其流来读取/写入内容。
...
m_Input = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
m_Output = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
...
// reading from stream
m_Input.read(buffer, readBytes, 1) ;
int readBytes=0;
while(readBytes < expectedBytes){
timeout = 0;
while((m_Input.available()) == 0 && timeout < ReadTimeout) {
timeout+=250;
// throws interrupted exception
Thread.sleep(250);// let control to other threads
}
if(timeout >= ReadTimeout){
// throw new timeout exception
}
if (m_Input.read(buffer, readBytes, 1) == -1) {
// throw stream/socket closed
}
readBytes++;
}
广告写作使用写法
...
//writting to stream
m_Output.write(buffer,..);