require "usb"

r = LibUSB.init(out ctx)
raise "libusb_init" if r < 0

cnt = LibUSB.get_device_list(ctx, out devices)
raise "libusb_get_device_list" if cnt < 0

cnt.times do |i|
  device = devices[i]

  LibUSB.get_device_descriptor(device, out device_descriptor)
  next unless device_descriptor.vendor_id == 0x0001 && device_descriptor.product_id == 0x0002

  r = LibUSB.open(device, out device_handle)
  raise "libusb_open" if r < 0

  r = LibUSB.claim_interface(device_handle, 0x00)
  raise "libusb_claim_interface" if r < 0

  data = Bytes.new(2)
  r = LibUSB.interrupt_transfer(device_handle, 0x81, data, data.size, out transferred, 0)
  raise "libusb_interrupt_transfer" if r < 0

  r = LibUSB.release_interface(device_handle, 0x00)
  raise "libusb_release_interface" if r < 0

  LibUSB.close(device_handle)
end

LibUSB.free_device_list(devices, 1)

LibUSB.exit(ctx)