Struct RootFeature 

pub struct RootFeature { /* private fields */ }

IRoot feature implementation.

Implementations

impl RootFeature

pub fn new(device_index: u8) -> Self

Creates a new root feature accessor.

Arguments

• device_index - Device index (0xFF for direct USB/Bluetooth)

pub fn direct() -> Self

Creates root feature for direct connection.

pub async fn ping(&self, channel: &HidapiChannel) -> Result<ProtocolVersion>

Pings the device and returns the protocol version.

This is the primary way to detect if a device supports HID++ and which version it uses.

Arguments

• channel - HID channel to communicate over

Errors

Returns an error if the device doesn’t respond, returns invalid data, or returns an HID++ error.

pub async fn get_feature_index( &self, channel: &HidapiChannel, feature_id: u16, ) -> Result<Option<u8>>

Gets the feature index for a given feature ID.

Arguments

• channel - HID channel to communicate over
• feature_id - The feature ID to look up (e.g., 0x2201 for DPI)

Returns

The feature index if found, or None if the feature is not supported.

Errors

Returns an error if HID++ communication fails or the device returns an error (other than “unknown feature”).