def open
      context = LIBUSB::Context.new
      device = context.devices(:idVendor => LEGO_VENDOR_ID, :idProduct => NXT_PRODUCT_ID).first
      raise ::LegoNXT::NoDeviceError.new("Please make sure the device is plugged in and powered on") if device.nil?
      @handle = device.open
      @handle.claim_interface(0)
    end
def open
      context = LIBUSB::Context.new
      device = context.devices(:idVendor => LEGO_VENDOR_ID, :idProduct => NXT_PRODUCT_ID).first
      raise ::LegoNXT::NoDeviceError.new("Please make sure the device is plugged in and powered on") if device.nil?
      @handle = device.open
      @handle.claim_interface(0)
    end
Opens the connection

 This is triggered automatically by intantiating the object.

 @return [nil]