bt_spp_get_service_port() Get the RFCOMM channel number of the established connection or the registered service.
bt_spp_init() Initialize the resources required for the Bluetooth library.
bt_spp_open() Create a Serial Port Profile (SPP) connection to a service on a remote Bluetooth device (server)
bt_spp_open_ex() Create a Serial Port Profile (SPP) connection to a service on a remote Bluetooth device (server) - an extended version of bt_spp_open.