0x2110 · smartShift – OpenLogi Docs

Read or write the scroll wheel mode (free-spin or ratchet) and the speed threshold at which the wheel automatically disengages into free-spin.

The original smartShift scroll-wheel feature. getRatchetControlMode (function 0) reads the current wheel mode, the auto-disengage speed threshold, and its factory default; setRatchetControlMode (function 1) writes them back. Fields passed as None (or 0 for the byte values) are left unchanged by the device.

wheelMode — Freespin (1) or Ratchet (2); reflects the software-set or button-set mode, not the transient auto-disengage state.
autoDisengage — 0x01–0xFE, quarter-turns per second at which a ratchet-mode wheel releases into free-spin; 0xFF keeps the ratchet permanently engaged.
autoDisengageDefault — the factory-default threshold stored alongside the active value.

Note: OpenLogi's SmartShift panel and ToggleSmartShift action drive the newer 0x2111 smartShiftEnhanced variant instead.

Spec: Logitech HID++ 2.0 — smartShift. Used by: Typed wrapper in openlogi-hidpp.

Function reference

The SmartShiftFeature wrapper (0x2110) exposes:

Methods

Function	HID++ fn	Signature	Returns
`get_ratchet_control_mode`	0	`()`	`RatchetControlMode`
`set_ratchet_control_mode`	1	`(wheel_mode: Option<WheelMode>, auto_disengage: Option<u8>, auto_disengage_default: Option<u8>)`	`()`

All methods are async and return Result<…, Hidpp20Error>.

Types

`RatchetControlMode`

Represents the ratchet control mode of the mouse wheel.

Field	Type	Description
`wheel_mode`	`WheelMode`	The mode the wheel is currently set to. Does not reflect the transient auto-disengage state.
`auto_disengage`	`u8`	Quarter-turns per second at which the wheel automatically disengages. `0xff` disables automatic disengagement (permanent ratchet).
`auto_disengage_default`	`u8`	The factory-default value of `auto_disengage`.

`WheelMode`

Represents the ratchet mode of the scroll wheel.

Variant	Value	Description
`Freespin`	`1`	Free-spin wheel mode.
`Ratchet`	`2`	Ratchet wheel mode.

Wire format

Both functions send a 3-byte short-report request payload. The response is accessed via extend_payload(), which always returns a 16-byte array (zero-padded from a short response); only bytes 0–2 carry meaningful data for get_ratchet_control_mode.

`get_ratchet_control_mode` (fn 0)

Request: [0x00, 0x00, 0x00] — no parameters; all bytes are zero.

Response (byte → field):

Byte	Field	Notes
0	`wheel_mode`	`WheelMode` enum: `1` = `Freespin`, `2` = `Ratchet`
1	`auto_disengage`	Quarter-turns/s threshold; `0xFF` = permanent ratchet
2	`auto_disengage_default`	Factory-default value of `auto_disengage`

`set_ratchet_control_mode` (fn 1)

Request: [wheel_mode_byte, auto_disengage_byte, auto_disengage_default_byte]

Byte	Source	Notes
0	`wheel_mode.map_or(0, u8::from)`	`0` = leave unchanged; `1` = `Freespin`, `2` = `Ratchet`
1	`auto_disengage.unwrap_or(0)`	`0` = leave unchanged; `0x01`–`0xFE` = threshold; `0xFF` = permanent
2	`auto_disengage_default.unwrap_or(0)`	`0` = leave unchanged; same range as byte 1

Response: not used (the device echoes the written values but the wrapper discards them).

Usage (Rust)

use hidpp::{device::Device, feature::smartshift::SmartShiftFeature};

// device: &mut Device, already created via Device::new(channel, index)
device.enumerate_features().await?;
if let Some(feat) = device.get_feature::<SmartShiftFeature>() {
    // Read current mode
    let mode = feat.get_ratchet_control_mode().await?;
    println!("wheel_mode={:?}, auto_disengage={}", mode.wheel_mode, mode.auto_disengage);

    // Switch to free-spin, keep the auto_disengage threshold unchanged
    feat.set_ratchet_control_mode(
        Some(hidpp::feature::smartshift::WheelMode::Freespin),
        None,
        None,
    ).await?;
}

0x2110 · smartShift

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