The bluetooth tutorial example worked for me. My android device is a SGT2 7.0. For the remote end I am using a KCwirefree BT radio connected to a FTDI USB to rx, tx converter from a PC.
I made two changes to the bluetooth example code, one for non-prefix mode, the other for connect insecure. Both of these changes can be found in B4A posts. I will migrate to prefix mode, once my programming skills improve. For now progress is good, and learning quickly.
I have used TeraTerm on PC to verify duplex communications. I will also be working with embedded application. To reduce hardware devices, and improve debugging, I am using VB6 application to emulate the embedded system communications dialog. VB6 communications also works using MSCOMM, in text mode.