OpenLogi0x6501 · gestures2
旧版手势描述符表——OpenLogi 借此找到并接管 MX Master 2S 的拇指滚轮，它早于专用的 0x2150 功能。
0x6501 gestures2 是罗技的旧版手势配置功能：设备会公布一张手势 id
描述符表，每一项标注是否存在、是否启用，以及——有时——能否接管给主机。
OpenLogi 只实现了它需要的那一小块：MX Master 2S 把横向拇指滚轮暴露为 0x6501 下的手势
id 46，而不是通过更新的专用
0x2150 thumbwheel
功能。封装会遍历描述符表找到该手势，算出它的接管索引，并可以接管或还原它。
规格： Logitech HID++ 2.0 —— x6501 gestures2（部分实现）。用于： 旧款 MX 鼠标的拇指滚轮捕获。
Function reference
The Gestures2Feature wrapper (0x6501) exposes:
Methods
| Function | HID++ fn | Signature | Returns |
|---|---|---|---|
thumbwheel | 0 (paged) | () | Option<ThumbwheelGesture> |
has_thumbwheel | 0 (paged) | () | bool |
thumbwheel_diverted | 0, 3 | () | Option<bool> |
set_thumbwheel_diverted | 0, 4 | (diverted: bool) | bool |
All are async and return Result<…, Hidpp20Error>. Merely exposing 0x6501
is not enough to assume a thumb wheel: touchpads and other gesture devices expose
the feature without one, which is why every call starts from the descriptor
table.
Types
ThumbwheelGesture
| Field | Type | Description |
|---|---|---|
diversion_index | Option<u16> | Sequential index among gestures that advertise the divertable bit. None means gesture 46 exists but cannot be diverted. |
Constants
| Name | Value | Description |
|---|---|---|
THUMBWHEEL_GESTURE_ID | 46 | The gestures2 id of the horizontal thumb wheel. |
Wire format
Descriptor scan (fn 0)
Request: [hi, lo, 0x00] — the big-endian index of the first descriptor field
on this page. The response carries up to eight two-byte fields:
| Byte | Meaning |
|---|---|
| high | 0x01 marks the end of the table. Bit 7 set marks a gesture entry; bit 1 marks it divertable. |
| low | The gesture id. |
The walk advances eight fields at a time, counting divertable gestures as it goes: that running count is the diversion index of the next divertable gesture. It stops at the end marker, at gesture 46, or after 1024 fields — the bound stops a malformed table from causing an unbounded probe loop.
Diversion state (fn 3) and write (fn 4)
The diversion bit for index i lives at byte i >> 3, mask 1 << (i & 7):
| Function | Payload | Notes |
|---|---|---|
| 3 (read) | [offset, 0x01, mask] | Response byte 0 AND mask → currently diverted. |
| 4 (write) | [offset, 0x01, mask, value] | value is mask to divert, 0 to restore. Needs a long HID++ report. |
Usage (Rust)
use hidpp::{device::Device, feature::gestures2::Gestures2Feature};
// device: &mut Device, already created via Device::new(channel, index)
device.enumerate_features().await?;
if let Some(feat) = device.get_feature::<Gestures2Feature>() {
if feat.has_thumbwheel().await? {
// Divert the wheel to the host; false when it isn't divertable.
let diverted = feat.set_thumbwheel_diverted(true).await?;
println!("thumb wheel diverted: {diverted}");
}
}