(Dis)Connecting bluetooth devices with Windows.Devices.Bluetooth.Rfcomm (WP8.1)
I would try CoolTerm and see if that works for you. I was having a similar issue connecting a speaker with a Sigma DSP chip inside via USB connection, so if you are having trouble seeing external devices it may be that the device is incompatible with your computer. Download CoolTerm and go to options and under Serial Port you should change your Port to the desired connection (bluetooth, usb, etc.) Then edit the options as necessary and go to the main window and hit connect and see if it works for you.