Logitech documents 2200_mousepointer.pdf, 4301_k750_solarkeyboard_lightandbattery.pdf, 6100_touchpadraw.pdf, 6110_touchmouseraw.pdf, logitech_hidpp10_specification_for_Unifying_Receivers.pdf have been created from .doc(x) files using LibreOffice. logitech_hidpp_2.0_specification_draft_2012-06-04.pdf was already a PDF, so no conversion was necessary. The contents of the aforementioned files are (C) Logitech. Retrieved from https://drive.google.com/?tab=mo&pli=1&authuser=0#folders/0BxbRzx7vEV7eWmgwazJ3NUFfQ28 (found at http://code.google.com/p/chromium/issues/detail?id=175572) usbmon.awk was a RE attempt before I found the spec, it helped me understand the packets when the specification was not available. You will find the HID++ 1.0 spec the most interesting, I hope to produce a pairing program soon. 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 The source is not too beautiful, but crafted quickly together while I learned more about the protocol. Set the DEBUG environment variable to get more verbose details. 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 Firmware version: 024.000.00018 Bootloader version: BL.000.006 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 succesfully 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 ~ Peter Wu