Android Bluetooth - Can't connect out

Question

I am developing an application which uses Bluetooth to connect to a device and send/receive data. I am doing all of my testing with a Nexus One phone.

I have never b

Answer 1

The solution, as it turns out, was to disable the server functionality of the Bluetooth service. By only using createRfcommSocketToServiceRecord and never calling listenUsingRfcommWithServiceRecord (in the BluetoothChat example this means never starting the "AcceptThread") the problem was fixed.

Even though these two calls are supposed to be totally separated and have no affect on each other (according to the Android docs), simply commenting out listenUsingRfcommWithServiceRecord fixed my supposedly unrelated issue.

I can take the Bluetooth Chat program unedited and it will not be able to establish an outgoing connection to ANY bluetooth device I have tested (laptops, desktops, headsets, etc.), but if I remove that one thing it works flawlessly as a client.

Anyway, I hope this will help someone else if they come across the same issue. This must be a bug with the Android OS, or possibly the firmware on the Nexus One.

Answer 2

I would ignore the stopDiscovery error - its good that you're cancelling discovery before making your connection. Per the SDK docs:

Because discovery is a heavyweight precedure for the Bluetooth adapter, this method should always be called before attempting to connect to a remote device with connect(). Discovery is not managed by the Activity, but is run as a system service, so an application should always call cancel discovery even if it did not directly request a discovery, just to be sure.

So with that said, were you able to get the Bluetooth Chat example to work before you made any modifications to the code?

The UUID you want for SPP/RFCOMM is:

static UUID UUID_RFCOMM_GENERIC = new UUID(0x0000110100001000L,0x800000805F9B34FBL);

or defined another way (both accomplish the same thing).

static final UUID UUID_RFCOMM_GENERIC = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");