0x2150 · thumbwheel

The horizontal thumb wheel on MX-line mice. getThumbwheelInfo reports its capabilities (resolution, native vs divertable, default direction); getThumbwheelStatus reads the current reporting mode; setThumbwheelReporting diverts the wheel so its rotation is delivered to OpenLogi as events instead of native scrolling. While diverted, the feature emits status updates carrying the rotation delta plus touch / tap flags.

OpenLogi diverts the thumb wheel to drive horizontal scroll and the ThumbwheelScrollUp / ThumbwheelScrollDown bindings, scaled by the thumb-wheel sensitivity setting.

Spec: Logitech HID++ 2.0 — x2150 thumbwheel. Used by: thumb-wheel bindings.

Function reference

The ThumbwheelFeature wrapper (0x2150) exposes:

Methods

get_thumbwheel_info, get_thumbwheel_status, and set_thumbwheel_reporting are async and return Result<…, Hidpp20Error>. listen is synchronous and returns a receiver directly.

Types

ThumbwheelInfo

Information about the thumbwheel as reported by get_thumbwheel_info.

ThumbwheelCapabilities

The capabilities the thumbwheel may support.

ThumbwheelDirection

Determines which rotation direction produces a positive value in ThumbwheelStatusUpdate::rotation. Direction descriptors (LeftOrBack, RightOrFront) are specific to device orientation.

ThumbwheelStatus

Current thumbwheel status as reported by get_thumbwheel_status.

ThumbwheelReportingMode

The mode how the thumbwheel reports its events.

Events

ThumbwheelFeature implements EmittingFeature<ThumbwheelEvent>. Call listen() to obtain an async_channel::Receiver<ThumbwheelEvent>. Events are only delivered when the thumbwheel is in ThumbwheelReportingMode::Diverted.

ThumbwheelEvent

ThumbwheelStatusUpdate

ThumbwheelRotationStatus

Wire format

All three methods use a 3-byte request payload. Getter responses are read from the 16-byte extended payload returned by extend_payload(). The event payload is delivered by the message listener on function sub-id 0.

get_thumbwheel_info (fn 0)

Request: [0x00, 0x00, 0x00] (no parameters)

Response (byte → field):

get_thumbwheel_status (fn 1)

Request: [0x00, 0x00, 0x00] (no parameters)

Response (byte → field):

set_thumbwheel_reporting (fn 2)

Request: [mode, invert, 0x00]

Response: ignored (no fields decoded).

StatusUpdate event (fn 0, sub-id 0)

Emitted by the device while in Diverted mode. The listener filters on function sub-id 0 via func.to_lo() != 0.

Usage (Rust)

use hidpp::feature::thumbwheel::{ThumbwheelFeature, ThumbwheelReportingMode};

// mut device: Device, already created via Device::new(channel, index)
device.enumerate_features().await?;

if let Some(feat) = device.get_feature::<ThumbwheelFeature>() {
    let info = feat.get_thumbwheel_info().await?;
    println!("native res: {}, diverted res: {}", info.native_resolution, info.diverted_resolution);

    // Divert the thumbwheel so HID++ events are delivered instead of native scrolling.
    feat.set_thumbwheel_reporting(ThumbwheelReportingMode::Diverted, false).await?;

    // Subscribe to rotation events.
    let rx = feat.listen();
    while let Ok(event) = rx.recv().await {
        println!("{event:?}");
    }
}