What is uuid in android bluetooth

UUID of bluetooth server and client

what is UUID in android bluetoothserversocket meant? how we can set UUID for bluetooth server and client?

UUID is a universal unique identifier, it is meant to be a unique identifier and it is designed to be unique in most cases. It is generated at random, there isn’t anything more about it really.

1 Answer 1

It is a long story but let’s short it. Yes, UUID is an universal unique identifier to mark one special items, e.g. profiles, or characters, or whatever, just like your driver license’s ID. On Bluetooth, SIG defined some official UUID and you can find here: https://www.bluetooth.com/specifications/assigned-numbers/service-discovery

Then regarding to the bluetoothserversocket , this is the SPP actually and SPP does have the UUID named 0x1101 . however more and more requests need that more SPP channel on one device, hence more and more Bluetooth stack vendor defined the multi-SPP support channel, but the official UUID only one, so we can define our spec UUID, which need client and server use the same UUID.

The value itself can be defined any value only if it is «universal unique».

Related

Hot Network Questions

Subscribe to RSS

To subscribe to this RSS feed, copy and paste this URL into your RSS reader.

Site design / logo © 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA . rev 2023.7.14.43533

By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy.

Источник

What is bluetooth uuid ? and how do i get it?

Solution 3: Unfortunately, I don’t think there is any good way to get the UUID’s supported by a BluetoothDevice with API level < 15. My understanding is that the SDP is a list of UUIDs that other devices can fetch.

What is bluetooth uuid ? and how do i get it?

I am tring to connect my app to server with bluetooth. but i dont know what is this uuid and how should i find it?

class ConnectThread extends Thread < private final BluetoothSocket mmSocket; private final BluetoothDevice mmDevice; // Get a BluetoothSocket to connect with the given BluetoothDevice try < // MY_UUID is the app's UUID string, also used by the server code tmp = device.createRfcommSocketToServiceRecord(MY_UUID); 

/// this gives me an error, how shoud i fix it?

If you are using BluetoothChat source code, then, locate UUID in file BluetoothChatService.java as shown below:

public class BluetoothChatService < . . // Unique UUID for this application private static final UUID MY_UUID_SECURE = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66"); private static final UUID MY_UUID_INSECURE = UUID.fromString("8ce255c0-200a-11e0-ac64-0800200c9a66"); . . 

Bluetooth - Having trouble with custom UUID in Android, you are using the official base UUID: xxxxxxxx-0000-1000-8000-00805f9b34fb, from which all upper 32-bit are reserved (some already assigned.) …

How do I get the UUID of a bluetooth device?

I need to know UUID on API 8 (2.2) or possibly 2.3.3.

As I understand the documentation, this should be allowed:

 phoneDevice = blueAdapter.getRemoteDevice(phoneAddress); ParcelUuid[] phoneUuids = phoneDevice.getUuids(); // Won't compile 

Eclipse gives me: "The method getUuids() is undefined for the type BluetoothDevice." But see: http://developer.android.com/reference/android/bluetooth/BluetoothDevice.html#getUuids()

Also, I would like to know how the UUIDs are "parceled" inside the ParcelUuid[]. In case I ever manage to get there, how do I retrieve a UUID from a parcelUuid[]? Documentation for Android bluetooth seems to be very poor, in my opinion.

What a joke! Now I try to get it from the intent, but this too gives: *"EXTRA_UUID cannot be resolved or is not a field"*:

intent.getParcelableExtra(BluetoothDevice.EXTRA_UUID); 

You have to use reflection to use the getUuids() and fetchUuidsWithSdp() on android version < 3. So, try the code:

Method method = phoneDevice.getClass().getMethod("getUuids", null); ParcelUuid[] phoneUuids = (ParcelUuid[]) method.invoke(phoneDevice, null); 

//this will support from API level 15 and above.

Broadcast Action: This intent is used to broadcast the UUID wrapped as a ParcelUuid of the remote device after it has been fetched. This intent is sent only when the UUIDs of the remote device are requested to be fetched using Service Discovery Protocol Always contains the extra field EXTRA_DEVICE Always contains the extra field EXTRA_UUID Requires BLUETOOTH to receive. Constant Value: "android.bluetooth.device.action.UUID" 

//no way to degrade its hardware related. there is no supporting jar also. http://developer.android.com/sdk/compatibility-library.html

Unfortunately, I don't think there is any good way to get the UUID's supported by a BluetoothDevice with API level < 15. I guess that's why they added the new functions in API 15.

Note, from the docs for BluetoothClass

BluetoothClass is useful as a hint to roughly describe a device (for example to show an icon in the UI), but does not reliably describe which Bluetooth profiles or services are actually supported by a device. Accurate service discovery is done through SDP requests, which are automatically performed when creating an RFCOMM socket with createrfcommsockettoservicerecord(UUID) and listenUsingRfcommWithServiceRecord(String, UUID).

So, perhaps the device class could be used as a hint as to what services will be available until you perform one of the listed functions. Certainly it doesn't hurt to check the class since this won't require any additional bluetooth operations.

Note that the service class is also available (it is part of the device class) but this is just a general class, not a listing of specific services (like from SDP).

try BluetoothAdapter class

any question, read: http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html

Android - BLE how to set uuid to 16bit, 1 Answer. Sorted by: 10. If you want to declare a 16-bit UUID, you have to use a base-uuid, which is fixed: 0000xxxx-0000-1000-8000 …

How do Bluetooth SDP and UUIDs work? (specifically for Android)

My understanding is that the SDP is a list of UUIDs that other devices can fetch.

According to this PDF from MIT, "A more general way to think of SDP is as an information database." Does this mean I can add multiple values to SDP? Since Android has BluetoothDevice.fetchUuidsWithSdp() , how do I set the UUIDs of a device?

Also, what does each section of an UUID mean? UUIDs look like 00000000-0000-1000-8000-00805F9B34FB , but what information does this convey?

An UUID identifies a service that is available on a particular device. So if you call BluetoothDevice.fetchUUidsWithSdp() your BroadcastReceiver will receive the relevant Intent ACTION_UUID containing the device and the service UUID. The bluetooth specification defines some common UUIDs.

If you don't want to connect to one of these well known services but intent to implement your own bluetooth application, then you have to just generate your own UUID (use uuidgen from a unix console or an online generator) that identifies your application/service. You can create an UUID instance in java like this UUID uuid = UUID.fromString("785da8ea-1220-11e5-9493-1697f925ec7b"); .

So if you create the server side for your bluetooth application on Android you typically do this

BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter(); BluetoothServerSocket serverSocket = adapter.listenUsingRfcommWithServiceRecord("YourHumanReadableServiceName", uuid); 

And this is where you "set" your UUID. The Android bluetooth API creates the SDP-entry consisting of YOUR application's UUID and name for you. Other devices can now retrieve this entry. Androids bluetooth stack will now associate a bluetooth channel to your BluetoothServerSocket. If you want to connect to this ServerSocket, the connecting side usually connects doing this:

// you will most likely already have this instance from a discovery or paired device list BluetoothDevice serverDevice = adapter.getRemoteDevice(bluetoothMacAddress); // connect to your ServerSocket using the uuid BluetoothSocket socket = serverDevice.createRfcommSocketToServiceRecord(uuid); socket.connect(); 

Android will again do the heavy lifting for you: It checks the SDP-Records on the remote device, looks up the bluetooth channel that corresponds to your service's UUID and connects using this information.

There is a common code snippet spooking around here on SO that advices you to use "reflection" to get to a hidden API looking similar to this code:

 try < // this is the way to go socket = device.createRfcommSocketToServiceRecord(uuid); socket.connect( ); >catch ( IOException exception ) < // don't do that! You will bypass SDP and things will go sideways. Method m = device.getClass().getMethod("createRfcommSocket", new Class[] ); socket = (BluetoothSocket) m.invoke(device, 1); socket.connect(); > 

Most people try this and it "just works" in their dev environment but you should know what you do using this. You actively bypass the SDP lookup that retrieves the right bluetooth channel to be used with your service and you will end up connecting to channel 1. If you have more than one Service running on the device, things WILL go sideways in this cases and you will end up in debugging hell 😉

I developed a small middleware called Blaubot to create small networks using bluetooth/wifi/nfc and experienced all sorts of problems on the devices I used to test with (12 models). It was often the case that the bluetooth stack was not fully functional anymore in cases where it got some load or after many connects/disconnects (which you usually will have, if you are developing your app). In these cases the device.createRfcommSocketToServiceRecord(uuid) would occasionally fail and only turning the bluetooth adapter off and on again helped to bring the bluetooth adapters back to life (in some cases only after a full power cycle). If this happens and you use the reflection method, you will probably not have much fun with bluetooth.

But if you know this and keep concurrent calls to the BluetoothAdapter within bounds, bluetooth connections and the adapters will be pretty stable.

What is bluetooth uuid ? and how do i get it?, The base UUID with service UUID, forms the complete UUID for each service. Any UUID outside this 232 is a custom uuid. Hence UUID in above code snippet, from BluetoothChat.java, is a custom UUID. New UUID may not be required if your application involves serial port profile (SPP), where UUID mentioned by you is suitable. – Code sample.private static final UUID MY_UUID_SECURE =UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");private static final UUID MY_UUID_INSECURE =UUID.fromString("8ce255c0-200a-11e0-ac64-0800200c9a66");Feedback

Источник

How do I get the UUID of a bluetooth device?

I need to know UUID on API 8 (2.2) or possibly 2.3.3. As I understand the documentation, this should be allowed:

 phoneDevice = blueAdapter.getRemoteDevice(phoneAddress); ParcelUuid[] phoneUuids = phoneDevice.getUuids(); // Won't compile 

Eclipse gives me: "The method getUuids() is undefined for the type BluetoothDevice." But see: http://developer.android.com/reference/android/bluetooth/BluetoothDevice.html#getUuids() Also, I would like to know how the UUIDs are "parceled" inside the ParcelUuid[]. In case I ever manage to get there, how do I retrieve a UUID from a parcelUuid[]? Documentation for Android bluetooth seems to be very poor, in my opinion. What a joke! Now I try to get it from the intent, but this too gives: *"EXTRA_UUID cannot be resolved or is not a field"*:

intent.getParcelableExtra(BluetoothDevice.EXTRA_UUID); 

Hi facing same problem , in my project have provide support from android 2.3.1 , min api level 8. Please help.

Hi. Long time passed fro this post but I am now facing this exact same issue. Do you have any workaround for that (my minimum API is 10) ?Thanks for any clue

5 Answers 5

You have to use reflection to use the getUuids() and fetchUuidsWithSdp() on android version < 3. So, try the code:

Method method = phoneDevice.getClass().getMethod("getUuids", null); ParcelUuid[] phoneUuids = (ParcelUuid[]) method.invoke(phoneDevice, null); 

//this will support from API level 15 and above.

Broadcast Action: This intent is used to broadcast the UUID wrapped as a ParcelUuid of the remote device after it has been fetched. This intent is sent only when the UUIDs of the remote device are requested to be fetched using Service Discovery Protocol Always contains the extra field EXTRA_DEVICE Always contains the extra field EXTRA_UUID Requires BLUETOOTH to receive. Constant Value: "android.bluetooth.device.action.UUID" 

//no way to degrade its hardware related. there is no supporting jar also. http://developer.android.com/sdk/compatibility-library.html

So, the way to do it is to create UUIDs? It's not a property of the hardware, it's just a number I make up, is that right?

Unfortunately, I don't think there is any good way to get the UUID's supported by a BluetoothDevice with API level < 15. I guess that's why they added the new functions in API 15.

BluetoothClass is useful as a hint to roughly describe a device (for example to show an icon in the UI), but does not reliably describe which Bluetooth profiles or services are actually supported by a device. Accurate service discovery is done through SDP requests, which are automatically performed when creating an RFCOMM socket with createRfcommSocketToServiceRecord(UUID) and listenUsingRfcommWithServiceRecord(String, UUID).

So, perhaps the device class could be used as a hint as to what services will be available until you perform one of the listed functions. Certainly it doesn't hurt to check the class since this won't require any additional bluetooth operations.

Note that the service class is also available (it is part of the device class) but this is just a general class, not a listing of specific services (like from SDP).

Источник