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Re: [pyusb-users] Problem accessing USB device
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From: Nicolas P. <nic...@aa...> - 2016-01-28 12:53:48
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Looks like I found the answer to my problem. On this page http://www.libusb.org/wiki/APIs, I've read : "libusb is not suited for HID class devices. While it is possible to use libusb with HID class devices it requires the original HID class driver to be replaced by a driver which supports libusb, and this leads to a quite poor user experience on any platform other than Linux. It is recommended to use HIDAPI <http://www.signal11.us/oss/hidapi/> instead. HIDAPI provides convenient cross-platform access to HID class devices and can do so without any kernel driver concerns across all supported platforms." Nicolas Le 28/01/2016 08:21, Nicolas Pinault a écrit : > 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...> > > *AATON-Digital* > 38000 Grenoble - France > Tel +33 4 7642 9550 > > http://www.aaton.com > http://www.transvideo.eu > French Technologies for Film and Digital Cinematography > > Follow us on Twitter > @Aaton_Digital > @Transvideo_HD > > Like us on Facebook > https://www.facebook.com/AatonDigital > > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > > > _______________________________________________ > pyusb-users mailing list > pyu...@li... > https://lists.sourceforge.net/lists/listinfo/pyusb-users -- *Nicolas PINAULT R&D electronics engineer *** ni...@aa... <mailto:ni...@aa...> *AATON-Digital* 38000 Grenoble - France Tel +33 4 7642 9550 http://www.aaton.com http://www.transvideo.eu French Technologies for Film and Digital Cinematography Follow us on Twitter @Aaton_Digital @Transvideo_HD Like us on Facebook https://www.facebook.com/AatonDigital |
