PyUSB: USB Scanner read fails on CENTOS 7

Question

I'm trying to implement driver mechanism for usb barcode scanner on Centos.

Using PyUSB,

Here is high-level code. I am trying to achieve is to be able to read QR-Codes and BarCodes when someone scans and send it to message queue without user interaction.

dev = usb.core.find(idVendor=VENDOR_ID, idProduct=PRODUCT_ID)
if dev.is_kernel_driver_active(0) is True:
    dev.detach_kernel_driver(0)
dev.set_configuration()
dev.reset()
data = dev.read(endpoint.bEndpointAddress, 120,
                    timeout=10000)
currentData = list(chunks(data))

This code work fine on the same system with Ubuntu operating system. But on Centos 7 , All I hear rapid beeps, and nothing read from the scanner.

Here is everything installed on Centos, almost similar to Ubuntu that I ran on the same machine.

"libgusb.x86_64                         0.2.9-1.el7                     @base
libgusb-devel.x86_64                   0.2.9-1.el7                     @base
libusb.x86_64                          1:0.1.4-3.el7                   @base
libusb-devel.x86_64                    1:0.1.4-3.el7                   @base
libusbmuxd.x86_64                      1.0.10-5.el7                    @base
libusbmuxd-devel.x86_64                1.0.10-5.el7                    @base
libusbmuxd-utils.x86_64                1.0.10-5.el7                    @base
libusbx.x86_64                         1.0.20-1.el7                    @base
libusbx-devel.x86_64                   1.0.20-1.el7                    @base
pyusb.noarch                           1.0.0-0.11.b1.el7               @base
usb_modeswitch.x86_64                  2.4.0-5.el7                     @base
usb_modeswitch-data.noarch             20160612-2.el7                  @base
usbmuxd.x86_64                         1.1.0-1.el7                     @base
usbredir.x86_64                        0.7.1-2.el7                     @base
usbutils.x86_64                        007-5.el7                       @base"

Not sure what's the isse.

If I run, bellow block in loop,

 print("Waiting to Read")
 data = dev.read(endpoint.bEndpointAddress, 120,
                    timeout=10000)
 currentData = list(chunks(data))

Output is Waiting to read

But why? Put the scanner in HID mode and use a HID library instead. — Ignacio Vazquez-Abrams, Nov 03 '17 at 22:54
Not sure how to do that. My Idea is to read the barcode scanner and post the data to a message queue without focusing on to a text area. Also not printing it into any other place even if the curser focused. — SrujanSreepathi, Nov 06 '17 at 23:45
You set the mode by scanning the appropriate code in the manual. If you float it from X then it won't be used for keyboard input. — Ignacio Vazquez-Abrams, Nov 06 '17 at 23:47

PyUSB: USB Scanner read fails on CENTOS 7

0 Answers0