31 lines
1.3 KiB
Plaintext
31 lines
1.3 KiB
Plaintext
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Notes on libusb and pyusb
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Libusb provides access to the USB bus from user space. It uses the
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files in /dev/bus/usb/*/*. The following commands are useful on Linux:
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List devices on the USB bus:
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lsusb
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Add -d 16c0:05dc for a specific device, -v for more information.
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List file permissions for bus 001 device 005:
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ls -l /dev/bus/usb/001/005
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These permissions default to 660 group root.
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List udev information for bus 001 device 005:
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udevadm info --query=all --name=/dev/bus/usb/001/005 --attribute-walk
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These items can be used in udev rules.
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Default USB permissions do not allow a non-root user to write to the bus.
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To change permissions, add a rule to /etc/udev/rules.d/local.rules like this:
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SUBSYSTEM=="usb", ATTR{idVendor}=="16c0" , ATTR{idProduct}=="05dc", MODE="0666", GROUP="dialout"
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Then notify udev with "udevadm control --reload_rules", or /etc/init.d/udev/restart. But
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on my system, I need to plug in the SoftRock and reboot.
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To install Libusb on Windows, follow the instructions in
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http://sourceforge.net/apps/trac/libusb-win32/wiki.
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Run the program libusb-win32*/bin/inf-wizard.exe.
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On Windows, when libusb-win32 is properly installed, Device Manager reports a
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top-level device "libusb-win32 devices" and a sub-device "DG8SAQ-I2C". Otherwise
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it reports "Unknown Device" under "Universal Serial Bus controllers".
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