Rust library and applications for the ChargerLAB POWER-Z KM003C USB-C power analyzer.

km003c-rs provides a cross-platform Rust implementation for communicating with the KM003C device, enabling real-time USB-C power analysis and USB Power Delivery message capture.

• Dual interface support: Vendor (bulk, ~0.6ms latency) or HID (interrupt)
• Cross-platform support using nusb
• Asynchronous communication with Tokio
• Automatic device discovery, initialization, and authentication

• Real-time voltage, current, and power measurements
• Two modes:
  • Simple ADC: Single-shot readings with temperature and statistics
  • AdcQueue streaming: High-speed continuous streaming (2, 10, 50, 1000 SPS)
• USB data line voltage measurements (D+, D-)
• USB-C CC line voltage measurements (CC1, CC2)

• Capture and parse USB PD messages
• Connection/disconnection event detection
• Full PD message parsing using the usbpd crate
• Support for SPR and EPR source capabilities
• Chunked message reassembly for EPR

• Model, firmware version, hardware version
• Serial number and UUID
• Hardware ID and authentication level

Core library providing:

• Device communication and automatic initialization
• Streaming authentication (required for AdcQueue)
• ADC and AdcQueue data parsing
• USB PD event parsing

Command-line tools:

• adc_simple - Single-shot ADC readings with device info
• adc_queue_simple - AdcQueue streaming demo
• test_usbpd - USB PD negotiation capture

GUI application featuring:

• Real-time voltage/current/power plots
• AdcQueue streaming with configurable sample rates
• Adjustable time window (2s to 5min or all data)
• Device info panel with auth status
• Connect/disconnect control

Python bindings for parsing KM003C data structures.

• Rust 1.75+ (uses let-else and let-chains)
• USB access permissions (udev rules on Linux)
• POWER-Z KM003C device

git clone https://github.com/okhsunrog/km003c-rs.git
cd km003c-rs
cargo build --release

Create udev rules for non-root access:

sudo cp 71-powerz-km003c.rules /etc/udev/rules.d/
sudo udevadm control --reload-rules
sudo udevadm trigger

The rules use the uaccess tag for secure, dynamic access to logged-in users.

cargo run --bin adc_simple

cargo run --bin adc_queue_simple -- --rate 50 --duration 10

cargo run --bin test_usbpd

cargo run --bin km003c-egui

use km003c_lib::{DeviceConfig, KM003C, GraphSampleRate};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Connect with vendor interface (Full mode - includes init and auth)
    let mut device = KM003C::new(DeviceConfig::vendor()).await?;

    // Access device info (always available in Full mode)
    let state = device.state().unwrap();
    println!("{}", state);  // Pretty-printed device info
    println!("AdcQueue enabled: {}", state.adcqueue_enabled);

    // Simple ADC reading
    let adc = device.request_adc_data().await?;
    println!("Voltage: {:.3} V", adc.vbus_v);
    println!("Current: {:.3} A", adc.ibus_a);

    // AdcQueue streaming (if authenticated)
    if device.adcqueue_enabled() {
        device.start_graph_mode(GraphSampleRate::Sps50).await?;
        // ... poll for samples ...
        device.stop_graph_mode().await?;
    }

    Ok(())
}

// Vendor interface (Full mode) - recommended, fastest
let config = DeviceConfig::vendor();

// HID interface (Basic mode) - most compatible, ADC/PD polling only
let config = DeviceConfig::hid();

// Skip USB reset (default on macOS for compatibility)
let config = DeviceConfig::vendor().skip_reset();

This implementation is based on reverse engineering documented at: km003c-protocol-research

The research repository contains:

• Complete protocol specification
• USB transport documentation
• PCAPNG captures and analysis tools
• Firmware analysis notes

• Device discovery and dual-interface communication
• Automatic initialization and streaming authentication
• Simple ADC measurements
• AdcQueue high-speed streaming (2-1000 SPS)
• USB PD message capture and parsing
• Memory read for device info/calibration
• Real-time GUI with plotting

• Linux (primary development platform)
• macOS (uses --no-reset by default for compatibility)
• Windows (uses cross-platform nusb)

• Rust: 1.75+ (stable)
• Platforms: Linux, Windows, macOS
• Hardware: POWER-Z KM003C

Contributions welcome! See the research repository for protocol details.

MIT License - see LICENSE file.

• km003c-protocol-research - Protocol reverse engineering
• usbpd - Rust USB PD protocol library