Logitech T650 Multi-Touch Driver Project

This repository provides the research, diagnostic tools, and driver implementation required to unlock the full 5-finger multi-touch capabilities of the Logitech T650 Rechargeable Touchpad on modern operating systems (Linux and Windows 10/11).

Important

Your T650 needs to be at firmware 041.001.00038 to use this anything earlier will not work.

1. The Problem

By default, the T650 identifies as a "Generic HID Mouse" when connected via a Unifying Receiver. This legacy compatibility mode hides the high-resolution digitizer data, resulting in:

• No Touchpad Settings: The OS does not recognize the device as a touchpad.
• Limited Gestures: Only 1-finger movement and 2-finger basic scrolling are available.
• Low Precision: Movement is restricted to standard mouse resolution rather than the native 12-bit digitizer precision.

2. The Solution: HID++ 2.0 Unlock

Our research into the HID++ 2.0 protocol (specifically Firmware 038) revealed that the device requires a specific "Unlock Key" to enable Raw Reporting Mode.

Hardware Constants

• VID: 0x046D (Logitech)
• PID: 0xC52B (Unifying Receiver)
• Interface: 2 (HID++ Protocol Interface)
• Feature Index: 0x10 (Multi-touch Feature)
• Unlock Sequence (Key A): 11 01 10 21 02

3. Repository Structure

Folder	Description
/tools	Diagnostic scripts to verify 5-finger coordinate data.
/drivers	User-space driver implementations (Linux libevdev).
/docs	Technical documentation of the 12-bit bit-packing and protocol.

4. Getting Started

Prerequisites

You must have Python 3.10+ installed along with the hidapi library:

pip install hidapi

Verification

To confirm your hardware is communicating correctly, run the diagnostic tool:

sudo python3 tools/finger_diagnostic.py

If successful, you will see a live update of 5-finger coordinates (X, Y) and the active contact bitmask.

5. OS Implementation Status

Linux (Ubuntu 24.04+) (work in progress,3 fingers click gesture working)

The T650 can be "tricked" into native mode. By sending the unlock command and power-cycling the device, the kernel re-enumerates it as a Precision Touchpad, enabling the native GNOME Touchpad settings panel.

Windows 10/11 (work in progress,see windows-experimental branch)

Work is ongoing to implement a user-space driver that translates raw HID++ packets into Windows Precision Touchpad (PTP) events or virtual keyboard/mouse shortcuts for gestures.

6. Known Issues & Troubleshooting

Kernel Locking: Sometimes the hid-logitech-dj driver prevents user-space scripts from writing to the device.

Reboot Persistence: The "Unlock" command is volatile and must be re-sent after a device power cycle or system reboot. Use the provided udev rules to automate this.

Important

This project is an independent research effort and is not affiliated with Logitech.