Module write 

HID++ reads and writes per feature — DPI, SmartShift, wheel modes, lighting, backlight, and diagnostics.

Each entry point takes a DeviceRoute and resolves it to an open channel through open_route_channel, so the same call works whether the device is behind a Bolt receiver or attached directly (USB cable / Bluetooth). Each route-addressed call re-enumerates and re-opens, while the corresponding _on entry points reuse a crate::SharedChannel already owned by inventory or a standalone capture session.

Structs

Dpi

A sensor resolution that fits HID++’s unsigned 16-bit DPI field.

DpiCapabilities

Supported DPI values reported by a device’s HID++ AdjustableDpi feature.

DpiInfo

Current DPI plus the supported values reported by the device.

EasySwitchHosts

The Easy-Switch channels of a multi-host device, read from 0x1815.

EasySwitchSlot

One Easy-Switch channel of a multi-host device.

FeatureEntry

Snapshot of one HID++ feature exposed by a device: protocol ID + version. Returned by dump_features for diagnostics.

FirmwareEntityInfo

Firmware fields for one entity whose record the device answered and this parser decoded.

HostOs

The operating system a keyboard’s platform descriptors are matched against.

HostOsInfo

The OS and version the computer on a slot recorded in the device.

LightingWrite

One complete solid-colour transaction, including RGB ownership rollback.

LitraDescriptor

A known Litra raw-HID identity and its static product metadata.

OsMask

Operating systems covered by a platform descriptor.

OsVersion

An OS version as a platform descriptor bounds it: a major version and a revision.

PointerScaling

A pointer-motion multiplier in 8.8 fixed point (0x0100 is 1×).

ReportRate

How often a device sends movement reports, in whole hertz.

ReportRateInfo

A device’s report rate and the rates it lets software choose.

ReprogControlEntry

Snapshot of one HID++ 0x1b04 reprogrammable control. Returned by dump_reprog_controls for diagnostics so new device controls can be identified before OpenLogi maps them to a first-class button.

RgbControlLease

0x8071 software control a lighting write left asserted, with the control and event flags the device reported before that claim.

ScrollWheelMode

Current HID++ 0x2121 wheel reporting mode.

Enums

FirmwareEntity

One firmware entity a device reports through HID++ 0x0003 function 1. Returned by dump_firmware_entities so a device report can name the exact firmware it is running.

HapticWaveform

A haptic waveform ID accepted by playWaveform.

HidppFeatureErrorKind

HID++ feature error kind in a serializable wire-safe form.

HidppOperation

HID++ operation being performed when a device write/read failed.

HostConnection

How a host slot reaches its computer.

HostOsKind

An operating system a host slot can record.

LightCommand

A semantic command accepted by the standalone-light layer.

LightingMethod

Which HID++ lighting path drives a solid keyboard colour. Auto is what the GUI/agent use; the explicit variants exist for the diag A/B test.

LitraModel

A supported Litra product model.

OsLayoutOutcome

What keep_os_layout_on did.

ScrollReportingTarget

Destination for vertical wheel movement reports.

ScrollResolution

Vertical wheel reporting resolution for HID++ 0x2121 HiResWheel.

WriteError

Error returned by HID++ read/write operations.

Constants

LITRA_BEAM_PRODUCT_ID

Litra Beam product ID.

LITRA_GLOW_PRODUCT_ID

Litra Glow product ID.

Functions

apply_litra

Apply a semantic Litra command through a raw HID route.

commands_for_light_settings

Expand protocol-neutral saved settings into only the controls advertised by a standalone light. Unsupported controls are omitted rather than sent speculatively, which keeps power-only and brightness-only drivers usable.

dump_features

Enumerate every HID++ feature the device on route reports — used by openlogi diag features to confirm which DPI / SmartShift / etc. feature IDs a given peripheral actually exposes (e.g. whether a mouse speaks 0x2201 AdjustableDpi, 0x2202 ExtendedAdjustableDpi, or both — write::dpi drives either).

dump_firmware_entities

Read every firmware entity the device on route reports.

dump_reprog_controls

Enumerate the device’s HID++ 0x1b04 reprogrammable controls. This is a diagnostics-only probe used to discover controls for newly released devices. For example, MX Master 4 has both a Gesture Button and a separate Haptic Sense Panel in the thumb area; this probe lets us identify the panel’s CID and capabilities before wiring it into the capture/remapping model.

encode_litra_command

Encode a semantic command into the exact fixed-width Litra report.

ensure_haptics_armed_on

Ensure the firmware haptic engine is armed: the enable flag set. Returns true when a repair write was needed.

find_litra

Finds a Litra descriptor by its complete writable raw-HID identity.

get_backlight

Read the current backlight state of the keyboard on route.

get_backlight_on

Read the current backlight state on an already-open SharedChannel.

get_dpi

Read the device’s current DPI on sensor 0 — companion to set_dpi. Used by openlogi diag dpi and any future Settings → Diagnostics surface that wants to display the current value without writing.

get_dpi_info

Read the current DPI and the supported DPI values for sensor 0 in one route/channel session.

get_dpi_info_on

Read current DPI and supported values on an already-open SharedChannel.

get_easy_switch_hosts

Read the Easy-Switch slots of the device on route.

get_easy_switch_hosts_on

Read the Easy-Switch slots on an already-open SharedChannel.

get_fn_lock

Read the keyboard’s Fn-lock state on route.

get_fn_lock_on

Read the keyboard’s Fn-lock state on an already-open SharedChannel.

get_pointer_scaling

Read the pointer-motion scaling of the device route reaches.

get_report_rate_info

Read the report rate and the rates the device lists on route.

get_report_rate_info_on

Read the report rate and the rates the device lists on an already-open SharedChannel.

get_scroll_wheel_mode

Read the current vertical wheel reporting mode.

get_scroll_wheel_mode_on

Read the current wheel mode on an already-open SharedChannel.

get_smartshift_status

Read the device’s current SmartShift mode + sensitivity — companion to toggle_smartshift.

get_smartshift_status_on

Read SmartShift mode and sensitivity on an already-open SharedChannel.

keep_os_layout_on

Keep the keyboard’s current Easy-Switch slot on host’s platform, on an already-open SharedChannel. A slot already on it is left alone; a write the keyboard does not read back surfaces as WriteError::UnsupportedResponse.

litra_model_for_route

Resolve a model only when the complete raw-HID route matches a registered Litra interface.

matches_litra

Whether an HID descriptor identifies a supported Litra interface.

play_haptic

Play a waveform immediately by route. A waveform the device does not advertise fails with WriteError::HapticWaveformUnsupported, and a play while the device reports a non-zero haptic status with WriteError::HapticsUnavailable, before anything is sent.

play_haptic_on

Play a waveform immediately on an open capture channel.

read_battery_raw

Diagnostic read of the device’s raw battery report — the unified 0x1004 fields, the legacy 0x1000 discharge_level/next_level/status, or the 0x1F20 ADC voltage and charging state. For openlogi diag battery: surfaces exactly what the firmware reports so a claim like “MX2S shows 0% while charging” can be confirmed against the wire instead of guessed (the GUI only ever shows the mapped value).

release_rgb_control

Hand lease back to the firmware on shared, as a long-lived host does when it leaves. available must reject retired publications and suspended host I/O. Bounded by the same five-second read deadline as a write.

rename_easy_switch_host

Name the computer on Easy-Switch slot of the device on route and return the slots the device reports afterwards. The checks of EasySwitchHosts::name_for run against a fresh read before anything is written; a name the device does not read back fails with WriteError::HostNameNotApplied.

rename_easy_switch_host_on

rename_easy_switch_host on an already-open SharedChannel.

set_dpi

Set sensor 0’s DPI for the device addressed by route.

set_dpi_on

Write DPI on an already-open SharedChannel — the fast path that skips enumeration and channel setup.

set_fn_lock

Write the keyboard’s Fn-lock state on route: true = the F-row sends F1–F12 without holding Fn. Returns the state the keyboard reports after the write; a keyboard that did not take it surfaces as WriteError::UnsupportedResponse.

set_fn_lock_on

Write keyboard Fn-lock on an already-open SharedChannel — the fast path that skips enumeration and channel setup.

set_keyboard_color

Set a device to a solid (r, g, b) colour, choosing the HID++ path automatically: 0x8070 → 0x8071 → 0x8081 → 0x8080.

set_keyboard_color_on

Set a solid keyboard colour on an already-open SharedChannel, using LightingMethod::Auto.

set_keyboard_color_with

set_keyboard_color with an explicit LightingMethod. Unsupported discovery permits fallback; failures after RGB ownership is claimed do not. Like LightingWrite::apply_on, this future must be driven to completion.

set_keyboard_color_with_on

Set a solid keyboard colour on an already-open SharedChannel with an explicit lighting method. Drive to completion; see LightingWrite::apply_on.

set_pointer_scaling

Write a pointer-motion scaling and return the value the device reports afterwards.

set_report_rate

Set the report rate on route and return what the device reports afterwards. A rate the device does not list fails with WriteError::ReportRateUnsupported before anything is written.

set_report_rate_on

Set the report rate on an already-open SharedChannel — the fast path that skips enumeration and channel setup.

set_scroll_inversion

Write the device’s native vertical-scroll inversion flag while preserving its current resolution. Enabling inversion selects native HID reporting; disabling it preserves the current reporting target so an unrelated host-side consumer does not lose diverted wheel events.

set_scroll_inversion_on

Write scroll inversion on an already-open SharedChannel, with the same reporting-target behavior as set_scroll_inversion.

set_scroll_resolution

Set only the wheel resolution while preserving the current inversion flag. Reporting is always normalized to native HID.

set_scroll_resolution_on

Set only the wheel resolution on an already-open SharedChannel.

set_scroll_wheel_mode

Set wheel resolution and native inversion together in one HID++ write.

set_scroll_wheel_mode_on

Set wheel resolution and inversion on an already-open SharedChannel.

set_smartshift

Write a full SmartShift configuration to route. The values are volatile device state and should be re-applied after reconnect. Callers that mean to change one field should read the current SmartShiftStatus and update it.

set_smartshift_on

Write a full SmartShift configuration on an already-open SharedChannel — the fast path that skips enumeration and channel setup.

set_smartshift_sensitivity

Set the SmartShift auto-disengage sensitivity on route, preserving the current mode. Returns the read-back status after the write so the caller can display and verify it.

toggle_smartshift

Toggle SmartShift mode (free ↔ ratchet) on route. Reads the current mode first, then writes the opposite — keeps current sensitivity. Returns the new mode written.

toggle_smartshift_on

Toggle SmartShift on an already-open SharedChannel.

update_backlight

Apply one BacklightChange to the keyboard on route, and return the read-back state.

update_backlight_on

update_backlight on an already-open SharedChannel.