java ME + bluetooth problem with device discovery [modified]

[mk_4]

Hello I'm writing bluetooth client application for my mobile phone and I got stuck on device discovery. My app can't discover any device, although in-built bluetooth app works fine. How can I make it work? My code for device discovery:

localDevice = LocalDevice.getLocalDevice();
discoveryAgent = localDevice.getDiscoveryAgent();
discoveryAgent.startInquiry(DiscoveryAgent.GIAC,this);

modified on Sunday, February 27, 2011 1:50 PM

[Peter_in_2780]

What you have done so far is initiate a search, which can take a long time. You have two ways to get the results: 1. write inquiryCompleted() in your DiscoveryListener implementation, and, when (or after) it is called, use discoveryAgent.retrieveDevices() to get an array of devices that have been discovered. 2. write deviceDiscovered() in your DiscoveryListener implementation, and, each time it is called, see if the device is what you are looking for. I tried both ways (and they both work), but settled on #1 for production code. Peter If you like the answer, vote for it

Software rusts. Simon Stephenson, ca 1994.

[mk_4]

Thank you for reply but I have these methods implemented. The problem is that my app can't find any device, though at least one - my laptop - is on and is discoverable. I can easily connect with it through in-built bluetooth app. Yet, another thing that puzzles me is why I can't get bluetooth address and friendly name from LocalDevice object. The only thing I get is empty string or null and my app suspends. Well it seems that the problem is caused by my phone. I rebooted it, launched my app and it worked but only once. Anyway I think that this topic can be considered as closed.

[Peter_in_2780]

In my experience, the phone's bluetooth manager can get totally confused if you do something it doesn't expect. The result is as you describe - reboot, your code works once (but the BT manager is locked up). I've found that you need to try and get "inside it's head" and imagine what state various BT internals might be in. Then avoid anything that might upset it. It took me a long time to develop code that could reliably switch the phone's BT connection back and forth between two external devices (PC, printer). Then when I tried it on a different brand of phone, I had to modify it again... Peter

Software rusts. Simon Stephenson, ca 1994.