Demos/Device/ClassDriver/GenericHID/HostTestApp/test_generic_hid_libusb.py

   1 #!/usr/bin/env python
   2
   3 """
   4              LUFA Library
   5      Copyright (C) Dean Camera, 2017.
   6
   7   dean [at] fourwalledcubicle [dot] com
   8            www.lufa-lib.org
   9 """
  10
  11 """
  12     LUFA Generic HID device demo host test script. This script will send a
  13     continuous stream of generic reports to the device, to show a variable LED
  14     pattern on the target board. Send and received report data is printed to
  15     the terminal.
  16
  17     Requires the PyUSB library (http://sourceforge.net/apps/trac/pyusb/).
  18 """
  19
  20 import sys
  21 from time import sleep
  22 import usb.core
  23 import usb.util
  24
  25 # Generic HID device VID, PID and report payload length (length is increased
  26 # by one to account for the Report ID byte that must be pre-pended)
  27 device_vid = 0x03EB
  28 device_pid = 0x204F
  29
  30 def get_and_init_hid_device():
  31     device = usb.core.find(idVendor=device_vid, idProduct=device_pid)
  32
  33     if device is None:
  34         sys.exit("Could not find USB device.")
  35
  36     if device.is_kernel_driver_active(0):
  37         try:
  38             device.detach_kernel_driver(0)
  39         except usb.core.USBError as exception:
  40             sys.exit("Could not detatch kernel driver: %s" % str(exception))
  41
  42     try:
  43         device.set_configuration()
  44     except usb.core.USBError as exception:
  45         sys.exit("Could not set configuration: %s" % str(exception))
  46
  47     return device
  48
  49 def send_led_pattern(device, led1, led2, led3, led4):
  50     # Report data for the demo is LED on/off data
  51     report_data = [led1, led2, led3, led4]
  52
  53     # Send the generated report to the device
  54     number_of_bytes_written = device.ctrl_transfer(  # Set Report control request
  55         0b00100001,  # bmRequestType (constant for this control request)
  56         0x09,        # bmRequest (constant for this control request)
  57         0,           # wValue (MSB is report type, LSB is report number)
  58         0,           # wIndex (interface number)
  59         report_data  # report data to be sent
  60     );
  61     assert number_of_bytes_written == len(report_data)
  62
  63     print("Sent LED Pattern: {0}".format(report_data))
  64
  65 def receive_led_pattern(hid_device):
  66     endpoint = hid_device[0][(0,0)][0]
  67     report_data = hid_device.read(endpoint.bEndpointAddress, endpoint.wMaxPacketSize)
  68     return list(report_data)
  69
  70 def main():
  71     hid_device = get_and_init_hid_device()
  72
  73     print("Connected to device 0x%04X/0x%04X - %s [%s]" %
  74           (hid_device.idVendor, hid_device.idProduct,
  75            usb.util.get_string(hid_device, 256, hid_device.iProduct),
  76            usb.util.get_string(hid_device, 256, hid_device.iManufacturer)))
  77
  78     p = 0
  79     while (True):
  80         # Convert the current pattern index to a bit-mask and send
  81         send_led_pattern(hid_device,
  82                          (p >> 3) & 1,
  83                          (p >> 2) & 1,
  84                          (p >> 1) & 1,
  85                          (p >> 0) & 1)
  86
  87         # Receive and print the current LED pattern
  88         led_pattern = receive_led_pattern(hid_device)[0:4]
  89         print("Received LED Pattern: {0}".format(led_pattern))
  90
  91         # Compute next LED pattern in sequence
  92         p = (p + 1) % 16
  93
  94         # Delay a bit for visual effect
  95         sleep(.2)
  96
  97 if __name__ == '__main__':
  98     main()