Logitech Unifying tool for Linux

See also the article on https://lekensteyn.nl/logitech-unifying.html

Logitech documents

I have learned a bit from the kernel source code hid-logitech-dj, but the "official" Logitech specification (HID++ 1.0) was much more useful. These documents can be found on https://lekensteyn.nl/files/logitech/.

Debuggers usbmon.awk - initial debugging tool used for tapping usbmon from debugfs hidraw.c - successor of usbmon.awk that can parse packets of usb payload. read-dev-usbmon.c - Reads data from /dev/usbmonX and show interpreted data in a more human-readable way.

Note: as a quick-n-dirty hack, I included hidraw.c at some point into the read-dev-usbmon program. Otherwise, I had no way to show the difference between a send or receive packet without adding to the same stdout stream. If I included it in the stderr pipe, then it would be interleaved with stdout in an unpredictable manner. This means that hidraw.c is currently unusable, it does not process data correctly.

Usage of USB debugger:

1. Use lsusb -d 046d:c52b to determine the bus number. If the output is "Bus 001 ..", your usb monitor device is at /dev/usbmon1.
2. sudo chgrp $USER /dev/usbmon1
3. sudo chmod g+r /dev/usbmon1
4. ./read-dev-usbmon /dev/usbmon1
5. Profit!

Pairing tool (ltunify) ltunify allows you to pair new devices, unpair existing devices or view information for those devices. In order to build the ltunify binary and install it to $HOME/bin/ltunify:

make ltunify
make install-home

If you intend to package ltunify or otherwise install it system-wide with a udevrule, you can use:

make ltunify
make install DESTDIR=$pkgdir bindir=/usr/bin udevrulesdir=/lib/udev/rules.d

Once installed, run ltunify --help for available options.

Usage of the pairing tool is pretty straight-forward. Example session:

$ ./ltunify list
/dev/hidraw0: Permission denied
Logitech Unifying Receiver device is not accessible.
Try running this program as root or enable read/write permissions
for /dev/hidraw0
$ sudo chgrp $USER /dev/hidraw0 && sudo chmod g+rw /dev/hidraw0 
$ ./ltunify list
Devices count: 1
Connected devices:
idx=1   Mouse   M525
$ ./ltunify info 1
Device index 1
Mouse
Name: M525
Wireless Product ID: 4013
Serial number: DAFA335E
Device was unavailable, version information not available.
$ ./ltunify unpair 1
Device 0x01 Mouse successfully unpaired
$ ./ltunify list
Devices count: 0
Connected devices:
$ ./ltunify pair
Please turn your wireless device off and on to start pairing.
Found new device, id=0x01 Mouse
$ ./ltunify list
Devices count: 1
Connected devices:
idx=1   Mouse   M525

TODO

• organize code in multiple files
• simplify code
• HID++ 2.0 debugging (transparent if possible)

~ Peter Wu lekensteyn@gmail.com