Hi Pavan, > How do I know what BlueZ versions refer to what Bluetooth specification & confrom to which version ? > I am particularly interested about BlueZ 3.36. > > It shows me a error "Can't read simple pairing mode" on a v2.1 hardware. make sure you use hcidump -X -V to capture what is going on there. Maybe your hardware doesn't support Simple Pairing. It is possible to built 2.1 devices without Simple Pairing support. Also you should switch to 4.22 or something more recent. Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html