Changes between Version 16 and Version 17 of FAQ


Ignore:
Timestamp:
01/14/12 21:47:32 (5 years ago)
Author:
stuge
Comment:

Mention more about Linux and Mac OS X problems with HID class

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  • FAQ

    v16 v17  
    2020 
    2121== Can I create a "driverless" device using HID class? == 
    22 Yes, sortof, but the device will only be really easy to access on Microsoft Windows (and Linux, if you can temporarily replace the driver, which libusb provides [http://libusb.sourceforge.net/api-1.0/group__dev.html#ga0bc7a17090debf6d2b2711c505ad9725 an API for], but which can require elevated system privileges). 
     22Yes, sortof, but the device will only be really easy to access on Microsoft Windows. On Linux you must detach the kernel driver, which libusb has an [http://libusb.sourceforge.net/api-1.0/group__dev.html#ga0bc7a17090debf6d2b2711c505ad9725 API] for, but this API can require elevated system privileges depending on system configuration. On Mac OS X you must install a codeless kext kernel driver and then reboot, before you can communicate with the device. 
    2323 
    2424It is important to remember that USB devices are never driverless, rather quite the opposite. Multiple kernel drivers are always involved: USB stack with USB core, USB hub drivers, maybe a composite class driver, and then ultimately a class- or device-specific driver. This is true for every operating system, and also when using libusb.