Folks,

I have successfully over the years conneted to various Bluetooth modules over SPP using the follwing method:

Finding the MAC address of the module from the results of that scan, then creating a com port using:

Then I can use a terminal emulator or my own Qt programs to connect the Bluetooth com port and send data just as I would a normal com port.

However, with this BT121 module that I'm using, for the first time, I can't do that. It just refuses to connect. It works fine on OS X.

If I look at the module end I can see that it connects, then disconnects, giving a reason that it was terminated by the remote host (ie the Linux laptop in this case).

I realise that this is likely not enough info to track down the issue, but I'm not sure what information would help and where I could get it from. Does anyone have any suggestions of things to try or further information I could get and give you to help track this down please?

Thanks!

You sound like you know what you're doing.
A son of mine studying for his bsce once spent 3 weeks googling and downloading bluetooth stacks, drivers of different versions and dlls and compiling as needed (he operated in m$ windows, now in Macs/IOS) and he failed totally with the occasional device.

If at first you don't succeed, give up!