I'm doing the same, extended the Bluetooth Chat example in a similar way to you.
Not tried with 4 devices yet, your experience is worrying! Any updates? Are you doleing out from a Collection of 7 UUIDs? My Asus EeePad or Nexus One can't sustain a Bluetooth audio stream at the same time as one of my connections, even if there's no data traffic. On Aug 31, 9:19 pm, novakom <[email protected]> wrote: > I am developing an app which will have multiple phones communicating > together concurrently via bluetooth. To this end, I extended the > BluetoothChat example to support multiple simultaneous connections. > Once I got it working with 3 phones, I ramped up to 4 but have > discovered that it appears that phones running Android 2.2 can only > support 2 simultaneous bluetooth connections, while phones running > 2.3.4 can support 3 (at least, if not more). Can anyone confirm this > as a known bug for 2.2? It would be good to know if this is just a > hard limitation. > > Phones I am testing with: > HTC Incredible (2.2) > Nexus S (2.3.4) > Nexus 1 (2.3.4) > Nexus 1 (2.3.4) > > Here's how I determined that there is this hard limit: > > My code extends the BluetoothChat sample program, as I said. > Unfortunately I cannot share it right now (company legal limitations) > but it's basically the same as the original except that all threads > are not killed when new connections are made, all ConnectThread and > ConnectedThread objects are stored in an array, and I kick off a new > AcceptThread whenever an incoming connection is turned into a > ConnectedThread. > > After instrumenting my code with lots of debug, what I've found is > that once my 2.2 device (the incredible) has established 2 > connections, it will literally hang at either the accept() in the > AcceptThread or at the connect() in the ConnectThread. This is true > with whichever order of connections are made. For example, if I do > the following: > 1. Incredible > NS > 2. Incredible > N1 (1) > 3. Incredible > N1 (2) > or > 1. Incredible > N1 (1) > 2. Incredible > N1 (2) > 3. Incredible > NS > or > 1. Incredible > N1 (either) > 2. Incredible > NS > 3. Incredible > N1 (either) > or > 1. NS > Incredible > 2. N1 (either) > Incredible > 3. N1 (either) > Incredible > > In all cases, the Incredible will Always hang on step 3, whether it's > on the connect() in the first 3 cases, or the accept() in the last > case. Debug shows that it hangs specifically on those calls (not the > RFComm socket creation calls or anything else). Now, there are other > potential connection orders but these are the basic ones that need to > work, so I'm not worried about interleaving connects and accepts right > now. > > The other interesting thing is that I instrumented an end program > method from the menu which calls cancel on all open threads. > According to the SDK, when you call close() on an open hanging socket, > it is supposed to throw an error. Well, if the app has already hung > on either accept() or connect() in any of the scenarios above, then > the close() call hangs as well and I have to forceclose the program. > > Other info: > - Using another N1 running 2.3.4, I found that I didn't have any > trouble connecting all 4 phones as long as the incredible wasn't in > the mix. > - Also, when a phone running 2.3.4 with 2 active connections tries to > connect to the incredible while the incredible has 2 other active > connections, the phone running 2.3.4 fails to connect and does not > hang, while attempting the connection in reverse has the (now) > expected hang. > - Also tried to connect 4 phones with a Samsung Infuse (2.2) and > another N1 running 2.2. Both cases had similar hangs (cannot > exhaustively check this thanks to limited access to the devices). > - When trying to establish a 3rd connection with a device which is not > there (turned off the bluetooth on one of the N1s), the connect() call > does NOT hang. However, if I then turn on BT on the 3rd phone and try > to reconnect, it's back to hanging at connect(). Therefore there > definitely appears to be some kind of connection management problem > when running 2.2. > - If I make 2 connections on the incredible, then close one, I can > open another. All closing/opening works fine as long as I'm only > trying to manage 2 connections. > > Anyways, as I said, if anyone can confirm that I simply cannot use my > 2.2. device for testing more than 2 concurrent connections, that would > be very helpful. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
