[pyusb-users] Problem accessing USB device

[Nicolas P. <nic...@aa...>]

Hi,

I'm trying to use a USB device under Windows7x64.
The device is HID like with custom protocol.
The USB device is recognised by Windows as a HID device (without error 
nor warning shown is device manager).
It works perfectly with a host running QNX OS.

With PyUSB :
Discovery of the device is OK.
Configuration of the device seems to be OK.
Reading/writing the device fails.

Here is the code I use :

import usb.core
import usb.util

class Test(object):
     def __init__(self):
         self.VendorId = 0x15A2
         self.ProductId = 0x0073
         self.dev = usb.core.find(idVendor=self.VendorId, 
idProduct=self.ProductId)
         if not self.dev :
             raise ValueError("Device not found")
         print self.dev

         self.dev.set_configuration()

         cfg = self.dev.get_active_configuration()
         intf = cfg[(0,0)]
         self.interface = cfg[(0,0)].bInterfaceNumber

         self.dev.set_interface_altsetting(interface = self.interface, 
alternate_setting = self.interface)

         print "Interface :", self.interface
         self.DeviceSetIdle()

     def DeviceSetIdle(self):
         self.dev.ctrl_transfer(bmRequestType = 
usb.util.build_request_type(usb.util.CTRL_OUT,
usb.util.CTRL_TYPE_CLASS,
usb.util.CTRL_RECIPIENT_INTERFACE),
                                bRequest = USB_HID_SET_IDLE_REQUEST,    
# 0x0A
                                wValue   = 0,#8 << 8,
                                wIndex   = self.interface,
                                data_or_wLength = None,
                                timeout  = 0)

if __name__ == '__main__':
     t = Test()

I get the following output :
DEVICE ID 15a2:0073 on Bus 003 Address 023 =================
  bLength                :   0x12 (18 bytes)
  bDescriptorType        :    0x1 Device
  bcdUSB                 :  0x200 USB 2.0
  bDeviceClass           :    0x0 Specified at interface
  bDeviceSubClass        :    0x0
  bDeviceProtocol        :    0x0
  bMaxPacketSize0        :   0x40 (64 bytes)
  idVendor               : 0x15a2
  idProduct              : 0x0073
  bcdDevice              :    0x2 Device 0.02
  iManufacturer          :    0x1 Freescale Semiconductor Inc.
  iProduct               :    0x2 Kinetis Bootloader
  iSerialNumber          :    0x0
  bNumConfigurations     :    0x1
   CONFIGURATION 1: 100 mA ==================================
    bLength              :    0x9 (9 bytes)
    bDescriptorType      :    0x2 Configuration
    wTotalLength         :   0x29 (41 bytes)
    bNumInterfaces       :    0x1
    bConfigurationValue  :    0x1
    iConfiguration       :    0x0
    bmAttributes         :   0xc0 Self Powered
    bMaxPower            :   0x32 (100 mA)
     INTERFACE 0: Human Interface Device ====================
      bLength            :    0x9 (9 bytes)
      bDescriptorType    :    0x4 Interface
      bInterfaceNumber   :    0x0
      bAlternateSetting  :    0x0
      bNumEndpoints      :    0x2
      bInterfaceClass    :    0x3 Human Interface Device
      bInterfaceSubClass :    0x0
      bInterfaceProtocol :    0x0
      iInterface         :    0x0
       ENDPOINT 0x81: Interrupt IN ==========================
        bLength          :    0x7 (7 bytes)
        bDescriptorType  :    0x5 Endpoint
        bEndpointAddress :   0x81 IN
        bmAttributes     :    0x3 Interrupt
        wMaxPacketSize   :   0x40 (64 bytes)
        bInterval        :    0xa
       ENDPOINT 0x2: Interrupt OUT ==========================
        bLength          :    0x7 (7 bytes)
        bDescriptorType  :    0x5 Endpoint
        bEndpointAddress :    0x2 OUT
        bmAttributes     :    0x3 Interrupt
        wMaxPacketSize   :   0x40 (64 bytes)
        bInterval        :    0xa
Interface : 0
Traceback (most recent call last):
   File 
"Z:\Cantar2\Processeur\Apps_2\PyCantarem2Update\src\PyCantarem2Update.py", 
line 244, in <module>
     t = Test()
   File 
"Z:\Cantar2\Processeur\Apps_2\PyCantarem2Update\src\PyCantarem2Update.py", 
line 154, in __init__
     self.DeviceSetIdle()
   File 
"Z:\Cantar2\Processeur\Apps_2\PyCantarem2Update\src\PyCantarem2Update.py", 
line 174, in DeviceSetIdle
     timeout  = 0)
   File "C:\Python27\lib\site-packages\usb\core.py", line 1043, in 
ctrl_transfer
     self.__get_timeout(timeout))
   File "C:\Python27\lib\site-packages\usb\backend\libusb1.py", line 
883, in ctrl_transfer
     timeout))
   File "C:\Python27\lib\site-packages\usb\backend\libusb1.py", line 
595, in _check
     raise USBError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBError: [Errno 22] Invalid parameter

As I am far from a USB ninja, I spent days documenting myself and 
searching the Internet for a solution without success.

What's wrong with my code ?

Nicolas

-- 
*Nicolas PINAULT
R&D electronics engineer
*** ni...@aa... <mailto:ni...@aa...>

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