0x4530 · dualPlatform

The dualPlatform feature lets a device persist its HID key-code table across two OS families. The selection is set during pairing or by short-pressing a dedicated OS-selection button. getPlatform (function 1) reads the active setting; setPlatform (function 2) writes it and echoes the committed value back; it does not trigger a PlatformChanged notification. A PlatformChanged event is emitted only when the user switches via the hardware button.

0x4530 is the predecessor of 0x4531 multiPlatform; a device exposing 0x4531 should be driven through that feature instead.

• IosOrMac (0) — iOS or macOS HID key-code table.
• AndroidOrWindows (1) — Android or Windows HID key-code table.

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

Function reference

The DualPlatformFeature wrapper (0x4530) exposes:

Methods

get_platform and set_platform are async and return Result<…, Hidpp20Error>. listen is synchronous and infallible.

Types

DualPlatformSelection

The platform a device is configured for. The selection is persistent, chosen during pairing or by short-pressing an OS-selection button; there is no default.

Events

DualPlatformFeature implements EmittingFeature<DualPlatformEvent>. Call listen() to obtain an async_channel::Receiver<DualPlatformEvent> that receives hardware-button switch events. set_platform does not trigger this event.

Wire format

Each request carries a 3-byte payload; responses are read from the returned long payload via extend_payload(). The event payload is parsed from the raw HID++ message.

get_platform (fn 1)

Request: [0x00, 0x00, 0x00] — all bytes are unused padding.

Response (byte → field):

set_platform (fn 2)

Request: [platform, 0x00, 0x00] — byte 0 is the u8 representation of the new DualPlatformSelection; bytes 1–2 are unused padding.

Response (byte → field):

PlatformChanged event (sub-id 0)

Emitted by the hardware OS-selection button. Decoded from the raw HID++ event message when the feature index and func.to_lo() == 0 match.

Usage (Rust)

use hidpp::{device::Device, feature::dual_platform::{DualPlatformFeature, DualPlatformEvent, DualPlatformSelection}};

// chan: Arc<HidppChannel>, device_index: u8
let mut device = Device::new(chan, device_index).await?;
device.enumerate_features().await?;
if let Some(feat) = device.get_feature::<DualPlatformFeature>() {
    // Read the current platform setting.
    let current = feat.get_platform().await?;
    println!("Current platform: {:?}", current);

    // Switch to Android/Windows key-code table and confirm the echo.
    let committed = feat.set_platform(DualPlatformSelection::AndroidOrWindows).await?;
    println!("Committed: {:?}", committed);

    // Listen for hardware-button platform-switch events.
    let rx = feat.listen();
    if let Ok(DualPlatformEvent::PlatformChanged(p)) = rx.recv().await {
        println!("Hardware switch → {:?}", p);
    }
}