I'm writing an application that is able to communicate with my PC. I have used the Bluetooth functionalities of the SDK 2.1.
I can find devices, get their MAC address, create an RFCOMM socket, but when I start the connection, I get the following error message.
Service discovery failed.
If I write a such application, is my Nexus One the client or the server?
OK, I got the same problem, but I think I can answer a few of your questions. If your PC opened an SPP Port, for example, by using "sdptool add --channel=3 SP" your Android phone would be the client opening a socket and connecting with this socket to the server (your PC or any other Bluetooth device, for example, GPS, mouse, etc.).
You can get this information by reading the article Bluetooth, the definition of a client did I take out of this article.
If you are opening an SPP Port on the server (your PC, etc.) you are offering a standard service and there is a special UUID assigned to this service. This would be: 00001101-0000-1000-8000-00805F9B34FB
if I'm not mistaken.
So I think we should get a qualified answer from an Android developer. Or ask this question on Thursday during the IRC office hours.