I'm currently working on an Android application that connects to an instrument via Bluetooth and need to write string commands and receive string responses back. Currently I have the connect/read/write working for TCP/IP over Wi-Fi and now trying to implement Bluetooth. But I am running into some roadblocks. I have been searching the web trying to find examples of something similar and haven't had any luck. I have been using the Android developer resource example: Bluetooth Chat as my main reference point.
My current code seems to work.. Then it throws a Service Discovery Failed exception at the point of the connection. I am using the DeviceListActivity class to do the discovery and selecting of the device I want to connect to. It returns anActivityResult and then my Bluetooth class waits for it to handle that and then does the connect to it. The code beneath is almost identical to the Bluetooth Chat App.
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if(!m_BluetoothAdapter.isEnabled())
{
m_BluetoothAdapter.enable();
}
switch (requestCode) {
case REQUEST_CONNECT_DEVICE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
// Get the device MAC address
String address = data.getExtras()
.getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
// Get the BLuetoothDevice object
BluetoothDevice device = m_BluetoothAdapter.getRemoteDevice(address);
// Attempt to connect to the device
connect(device);
}
break;
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
// Bluetooth is now enabled, so set up a chat session
}
else {
// User did not enable Bluetooth or an error occured
Toast.makeText(this, "Bluetooth not enabled", Toast.LENGTH_SHORT).show();
finish();
}
}
}
This is my connect function:
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private void connect(BluetoothDevice device) {
m_Device = device;
BluetoothSocket tmp = null;
// Get a BluetoothSocket for a connection with the
// given BluetoothDevice
try {
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
}
catch (IOException e) {
}
m_Socket = tmp;
m_BluetoothAdapter.cancelDiscovery();
try {
// This is a blocking call and will only return on a
// successful connection or an exception
m_Socket.connect();
}
catch (IOException e) {
try {
m_Socket.close();
}
catch (IOException e2) {
}
return;
}
}
Hopefully, whatever I am doing wrong is simple, but I'm afraid it's never that easy. This is my first time doing any Bluetooth development, and maybe I'm doing something blatantly wrong... But I'm not sure why I get the service discovery failed exception.
You can pair/find the device at all times manually on the phone... It does require a passcode, but I don't think that is the problem that I am having.
After three days I got it figured out thanks to some very helpful posts.
I had to replace:
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
with:
Method m = device.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
tmp = (BluetoothSocket) m.invoke(device, 1);
and voilà it works!
As of API 15 you can use the following method:
Try replacing your UUID with the return value of getUuids() method of BluetoothDevice class.
What worked for me was something like this:
UUID uuid = bluetoothDevice.getUuids()[0].getUuid();
BluetoothSocket socket = bluetoothDevice.createRfcommSocketToServiceRecord(uuid);
The reason this works is that different devices support different UUIDs and by getting the UUIDs of the device using getUuids you are supporting all features and devices.
Another interesting new method (supported since API 14) is this: BluetoothHealth.getConnectionState. Haven't tried it but looks promising...
This was a suggested edit from an anonymous user attempting to reply to the accepted answer.
One big difference between your before and after code is the UUID you are passing. I found my answer here: http://developer.android.com/reference/android/bluetooth/BluetoothDevice.html#createRfcommSocketToServiceRecord(java.util.UUID)
I had to replace:
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
with:
private static final UUID SPP_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
tmp = device.createRfcommSocketToServiceRecord(SPP_UUID);
and voila it works!
The original code is for a peer to peer android app. It makes no sense to use the app UUID when connecting to a simple serial bluetooth device. Thats why discovery fails.
So as it mentioned above, the point is that you need to use the UUID that the server is waiting for.
If you are connecting to a bluetooth device, such as a headset or mouse, you need to check which UUIDs the device is listening for. You can see the UUIDs like this.
UUID[] uuids = bluetoothDevice.getUuids();
And if you want to know what these UUIDs mean, see this.
This is a realy old one question but i found that using the createInsecureRfcommSocketToServiceRecord() instead of createRfcommSocketToServiceRecord() along with the getUuids() previously mentioned do the trick for me
UUID uuid = bluetoothDevice.getUuids()[0].getUuid();
BluetoothSocket socket = bluetoothDevice.createInsecureRfcommSocketToServiceRecord(uuid);
Related
I would like to manually connect a bluetooth device with its MAC address because it is faster and I know exactly which MAC to connect.
I use this method to get the BluetoothDevice : http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#getRemoteDevice%28byte[]%29
But the Android doc does not say if Android ensure that the device is in range before creating the BluetoothDevice object.
Do you have this information ?
My code can automatically connect the device, and I would like to check if the target is in range before trying to connect, but without perform a large scan (which can be long...)
When local device connects to remote device using BluetoothSocket, an exception is required.
If remote device isn't in range, It's not found
private class ConnectThread extends Thread {
public ConnectThread(BluetoothDevice device, boolean isSecure, UUID sharedUUID) throws IncorrectSetupException {
try {
//Secure connections requires to get paired before connect
//Insecure connections allows to connect without pairing
if (isSecure) {
mSocket = device.createRfcommSocketToServiceRecord(sharedUUID);
} else {
mSocket = device.createInsecureRfcommSocketToServiceRecord(sharedUUID);
}
} catch (IOException e) {
//Is there some problem with the setup?
}
}
public void run() {
try {
mSocket.connect();
} catch (IOException e) {
//If device is not found, this exception is throwed
}
}
}
I am trying to establish Bluetooth connection between an Android device with other mobile phone over Handsfree profile. I am using following code -
private static final UUID MY_UUID = UUID.fromString("0000111F-0000-1000-8000-00805F9B34FB"); // UUID for Hands free profile
// Some code...
// Get Bluetooth Adapter.
m_oBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// Some code...
// For paired BT device, getting a connection established.
if(null != m_oBluetoothDevice)
{
if(BluetoothDevice.BOND_BONDED == m_oBluetoothDevice.getBondState())
{
try
{
m_oBluetoothSocket = m_oBluetoothDevice.createRfcommSocketToServiceRecord(MY_UUID);
m_oBluetoothSocket.connect();
Log.i(TAG, "Socket Connected");
}
catch(Exception e)
{
if(null != m_oBluetoothSocket)
{
Log.i(TAG, "Closing socket");
try
{
m_oBluetoothSocket.close();
}
catch (Exception e1)
{
Log.i(TAG, "Error while closing socket : " + e1.getMessage());
}
}
}
}
}
I can create RFCOMMSocket using this code.
Now I want to send AT commands based on Bluetooth Hands-Free profile. e.g. If other mobile phone receives a phone call, my Android device can reject this call by sending AT command- "+CHUP". I am not sure whether this is possible or not.
At this point, I am stuck. I have read Bluetooth APIs where I found -
BluetoothHeadset.ACTION_VENDOR_SPECIFIC_HEADSET_EVENT
Can we use this Intent for sending AT commands? Is this a proper way to send AT command based on Bluetooth Hands-Free profile? Please someone help me out and give me proper direction.
Any input from you all will be great help for me.
Thanks in advance.
You need to create InputStream and OutputStream so you can talk to the phone:
mmInStream = m_oBluetoothSocket.getInputStream();
mmOutStream = m_oBluetoothSocket.getOutputStream();
To setup the HFP connection you start to send:
mmOutStream.write("AT+BRSF=20\r".getBytes());
Where 20 is code for what you support of HFP.
And to read from the phone:
buffer = new byte[200];
mmInStream.read(buffer);
command = new String(buffer).trim();
So now you can talk beetwen the devices and you can read more about the Handsfree profile on https://www.bluetooth.org/docman/handlers/downloaddoc.ashx?doc_id=238193
Adding reference to AT commnads
http://forum.xda-developers.com/showthread.php?t=1471241
http://www.zeeman.de/wp-content/uploads/2007/09/ubinetics-at-command-set.pdf
Iam trying to connect to a socket by using the connect method. Iam generating a String containing the UUID like this:
MY_UUID = UUID.fromString("45341da0-c9c1-11e1-9b21-0800200c9a66");
Then constructing a BluetoothSocket like this:
BluetoothSocket tmp = null;
I also want to connect to a specific device by its mac-address:
BluetoothDevice device = BluetoothAdapter.getDefaultAdapter().getRemoteDevice("00:1B:DC:0F:EC:7E");
and then making the bluetoothSocket
try {
tmp = device.createInsecureRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
Toast.makeText(getApplicationContext(), "Exception1: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
Just for to test I added a breakpoint where the tmp object is been initialized inside the try catch. But it's only containing NULL The remote device does support OBEX OPP, but this is just a layer above the RFCOMM in the bluetooth stack, so I think my device should support RFCOMM for connections. Can anybody tell me why my tmp object is set to null?
Is there anyway I can test whenever the socket is created?
I have a device which supports the OBEX Object Push Profile, this profile is based upon the Serial Port Profile. My guess is that I can use the Android Bluetooth Chat example for connecting this device to my Android Phone. But I ran into a problem, regarding the socket.accept() functionality in the android SDK. I try to accomplish to connect my phone with this device like this:
adapter = BluetoothAdapter.getDefaultAdapter();
device = adapter.getRemoteDevice("00:1B:DC:0F:EC:7E");
AcceptThread = new AcceptThread(true, adapter, device);
AcceptThread.start();
The constructor in AcceptThread is coded like this:
public AcceptThread(boolean secure, BluetoothAdapter adapter, BluetoothDevice device) {
BluetoothServerSocket tmp = null;
this.adapter = adapter;
this.device = device;
// Create a new listening server socket
try {
tmp = adapter.listenUsingInsecureRfcommWithServiceRecord(device.getName(), UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
} catch (Exception e) {
Log.e(TAG, ".AcceptThread # listen() failed", e);
}
mmServerSocket = tmp;
}
The problem is when I try to do a connect() as I said before
public void run() {
BluetoothSocket socket = null;
// Listen to the server socket if we're not connected
while (mState != STATE_CONNECTED) {
try {
// This is a blocking call and will only return on a
// successful connection or an exception
Log.d(TAG, "AcceptThread.run: accepting server socket connection");
socket = mmServerSocket.accept(20000);
Log.d(TAG, ".AcceptThread.run # server socket connection accepted");
} catch (Exception e) {
Log.e(TAG, ".run # accept() failed: "+e);
break;
}
}
}
As you can see the ServerSocket accept every incomming connection for 20 seconds or 20000 ms. When the time is up, the app will throw an IOException like this
07-11 10:30:08.355: E/SIMPLECONNECT(1301): .run # accept() failed: java.io.IOException: Connection timed out
which tells me that my device couldnt connect to my android phone. The device doesnt have a connect button on the display, just a send functionalitywhich will send a file to my phone. I believe that this send functionality also do a connect in the background, but I am not sure.
Can anybody pinpoint any solutions for me? I am running my app on a Samsung Galaxy SIII with Android 4.0.4
I finally solved it, the problem is that different Android Versions and different devices seemes to need different sockets. I tryed it with Samsung Galaxy XCOVER, Tab1, Tab2, Nexus, Note, Motorola Defy and HTC Flyer.
The Sockets I used are:
A:
Method m = mmDevice.getClass().getMethod("createRfcommSocket", new Class[] { int.class });
mSocket = (BluetoothSocket) m.invoke(mmDevice, Integer.valueOf(1));
B:
Method m = mmDevice.getClass().getMethod("createInsecureRfcommSocket", new Class[]{int.class});
mSocket=(BluetoothSocket)m.invoke(mmDevice,Integer.valueOf(1));
C:
mSocket=BluetoothAdapter.getDefaultAdapter().getRemoteDevice(mmDevice.getAddress()).createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
Android 4.0.x works for Nexus, Flyer,Tab1 with A,B
Android 4.0.3 works for Tab2 with B
Android 3,6,x works for DEFY with A,B
Android 2.3.6 works for XCOVER with C
I can't find a solution witch works for all devices and I;m not able to find out witch socket will work before I create and use the Socket, especially the XCOVER perform the connect() for all Sockets without throwing an exception, but catch if i try tro write(). So if you want to setup a bloothoh connection wich works for all devices you have to create the sockets, connect an write and then remeber the socket wich works (e.g. in preferences)
I have spent some time researching Android's ability to communicate with bluetooth devices that are designed to communicate over a Bluetooth COM port on a PC. I haven't been able to find a definitive answer, so I thought I'd ask here. I want to make sure that this is possible with Android.
I am new to Bluetooth communications, but the research I've done so far lead me to RFCOMM which somewhat sounded like what I wanted. Unfortunately, I'm still unable to confirm that this is in fact possible.
Any help/resources on this would be greatly appreciated.
Yes, Android can connect to Bluetooth COM ports on PC's. I am currently developing such an application. Here is a code example (Ite requires the bluetooth permissions te be set in the Manifest.xml file):
<uses-permission android:name="android.permission.BLUETOOTH" />
Java:
BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
if (adapter == null) {
// Device does not support Bluetooth
finish(); //exit
}
if (!adapter.isEnabled()) {
//make sure the device's bluetooth is enabled
Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBluetooth, REQUEST_ENABLE_BT);
}
final UUID SERIAL_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //UUID for serial connection
mac = "00:15:83:3D:0A:57"; //my laptop's mac adress
device = adapter.getRemoteDevice(mac); //get remote device by mac, we assume these two devices are already paired
// Get a BluetoothSocket to connect with the given BluetoothDevice
BluetoothSocket socket = null;
OutputStream out = null;
try {
socket = device.createRfcommSocketToServiceRecord(SERIAL_UUID);
} catch (IOException e) {}
try {
socket.connect();
out = socket.getOutputStream();
//now you can use out to send output via out.write
} catch (IOException e) {}