def open
      if open?
        self.open_count += 1
        if open_count < 1
          HIDAPI.debug "open_count for open device #{path} is #{open_count}"
          self.open_count = 1
        end
        return self
      end
      self.open_count = 0
      begin
        self.handle = usb_device.open
        raise 'no handle returned' unless handle

        begin
          if handle.kernel_driver_active?(interface)
            handle.detach_kernel_driver(interface)
          end
        rescue LIBUSB::ERROR_NOT_SUPPORTED
          HIDAPI.debug 'cannot determine kernel driver status, continuing to open device'
        end

        handle.claim_interface(interface)

        self.input_endpoint = self.output_endpoint = nil

        # now we need to find the endpoints.
        usb_device.settings
            .keep_if {|item| item.bInterfaceNumber == interface}
            .each do |intf_desc|
          intf_desc.endpoints.each do |ep|
            if ep.transfer_type == :interrupt
              if input_endpoint.nil? && ep.direction == :in
                self.input_endpoint = ep.bEndpointAddress
                self.input_ep_max_packet_size = ep.wMaxPacketSize
              end
              if output_endpoint.nil? && ep.direction == :out
                self.output_endpoint = ep.bEndpointAddress
              end
            end
            break if input_endpoint && output_endpoint
          end
        end

        # output_ep is optional, input_ep is required
        raise 'failed to locate input endpoint' unless input_endpoint

        # start the read thread
        self.input_reports = []
        self.thread_initialized = false
        self.shutdown_thread = false
        self.thread = Thread.start(self) { |dev| dev.send(:execute_read_thread) }
        sleep 0.001 until thread_initialized

      rescue =>e
        handle.close rescue nil
        self.handle = nil
        HIDAPI.debug "failed to open device #{path}: #{e.inspect}"
        raise DeviceOpenFailed, e.inspect
      end
      HIDAPI.debug "opened device #{path}"
      self.open_count = 1
      self
    end
def open
      if open?
        self.open_count += 1
        if open_count < 1
          HIDAPI.debug "open_count for open device 
          self.open_count = 1
        end
        return self
      end
      self.open_count = 0
      begin
        self.handle = usb_device.open
        raise 'no handle returned' unless handle

        begin
          if handle.kernel_driver_active?(interface)
            handle.detach_kernel_driver(interface)
          end
        rescue LIBUSB::ERROR_NOT_SUPPORTED
          HIDAPI.debug 'cannot determine kernel driver status, continuing to open device'
        end

        handle.claim_interface(interface)

        self.input_endpoint = self.output_endpoint = nil

        
        usb_device.settings
            .keep_if {|item| item.bInterfaceNumber == interface}
            .each do |intf_desc|
          intf_desc.endpoints.each do |ep|
            if ep.transfer_type == :interrupt
              if input_endpoint.nil? && ep.direction == :in
                self.input_endpoint = ep.bEndpointAddress
                self.input_ep_max_packet_size = ep.wMaxPacketSize
              end
              if output_endpoint.nil? && ep.direction == :out
                self.output_endpoint = ep.bEndpointAddress
              end
            end
            break if input_endpoint && output_endpoint
          end
        end

        
        raise 'failed to locate input endpoint' unless input_endpoint

        
        self.input_reports = []
        self.thread_initialized = false
        self.shutdown_thread = false
        self.thread = Thread.start(self) { |dev| dev.send(:execute_read_thread) }
        sleep 0.001 until thread_initialized

      rescue =>e
        handle.close rescue nil
        self.handle = nil
        HIDAPI.debug "failed to open device 
        raise DeviceOpenFailed, e.inspect
      end
      HIDAPI.debug "opened device 
      self.open_count = 1
      self
    end
def open if open? self . open_count += 1 if open_count < 1 HIDAPI . debug "open_count for open device #{path} is #{open_count}" self . open_count = 1 end return self end self . open_count = 0 begin self . handle = usb_device . open raise 'no handle returned' unless handle begin if handle . kernel_driver_active? ( interface ) handle . detach_kernel_driver ( interface ) end rescue LIBUSB :: ERROR_NOT_SUPPORTED HIDAPI . debug 'cannot determine kernel driver status, continuing to open device' end handle . claim_interface ( interface ) self . input_endpoint = self . output_endpoint = nil # now we need to find the endpoints. usb_device . settings . keep_if { | item | item . bInterfaceNumber == interface } . each do | intf_desc | intf_desc . endpoints . each do | ep | if ep . transfer_type == :interrupt if input_endpoint . nil? && ep . direction == :in self . input_endpoint = ep . bEndpointAddress self . input_ep_max_packet_size = ep . wMaxPacketSize end if output_endpoint . nil? && ep . direction == :out self . output_endpoint = ep . bEndpointAddress end end break if input_endpoint && output_endpoint end end # output_ep is optional, input_ep is required raise 'failed to locate input endpoint' unless input_endpoint # start the read thread self . input_reports = [ ] self . thread_initialized = false self . shutdown_thread = false self . thread = Thread . start ( self ) { | dev | dev . send ( :execute_read_thread ) } sleep 0.001 until thread_initialized rescue => e handle . close rescue nil self . handle = nil HIDAPI . debug "failed to open device #{path}: #{e.inspect}" raise DeviceOpenFailed , e . inspect end HIDAPI . debug "opened device #{path}" self . open_count = 1 self end
Opens the device.

 Returns the device.
Opens the device .