0x1004 · unifiedBattery

The modern, unified battery feature — one call for percentage, a coarse level, and charge status, replacing the older 0x1000 batteryStatus / 0x1001 batteryVoltage features. getBatteryCapabilities reports what the device can measure; getBatteryInfo returns the charging percentage, a BatteryLevel (full / good / low / critical), and a BatteryStatus (charging, discharging, …). The feature also emits live updates as the device pushes them.

OpenLogi reads it for the battery percentage and charge state shown in the device carousel and the list inventory.

Spec: Logitech HID++ 2.0 — x1004 unifiedBattery. Used by: battery percentage / charge state.

Function reference

The UnifiedBatteryFeature wrapper (0x1004) exposes:

Methods

get_battery_capabilities and get_battery_info are async and return Result<…, Hidpp20Error>. listen is synchronous and returns a channel receiver directly.

Types

BatteryCapabilities

Represents the capabilities of this feature and the battery itself.

BatteryInfo

Represents information about the current battery charge.

BatteryLevel

Represents an approximate level of the battery charge.

BatteryStatus

Represents the charging status of the battery.

Events

UnifiedBatteryFeature implements EmittingFeature<BatteryEvent>. Call listen() to obtain a channel receiver that yields BatteryEvent values pushed by the device.

BatteryEvent

Wire format

Both request payloads are 3 zero bytes; the device replies with a 16-byte long-format payload and the crate reads the first few bytes via extend_payload().

get_battery_capabilities (fn 0)

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

Response (byte → field):

get_battery_info (fn 1)

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

Response (byte → field):

InfoUpdate event (fn 0, event sub-id 0)

The device pushes this event unsolicited whenever battery state changes. The crate's message listener parses it identically to get_battery_info:

Usage (Rust)

use hidpp::{
    device::Device,
    feature::{EmittingFeature, unified_battery::UnifiedBatteryFeature},
};

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

if let Some(feat) = device.get_feature::<UnifiedBatteryFeature>() {
    // Query static capabilities once
    let caps = feat.get_battery_capabilities().await?;
    println!("rechargeable={}, percentage={}", caps.rechargeable, caps.percentage);

    // Poll current state
    let info = feat.get_battery_info().await?;
    println!("{}% — {:?} / {:?}", info.charging_percentage, info.level, info.status);

    // Subscribe to live updates pushed by the device
    let rx = feat.listen();
    while let Ok(event) = rx.recv().await {
        println!("battery event: {:?}", event);
    }
}