km003c-rs

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

Overview

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.

Features

🔌 Device Communication

• USB HID communication (VID: 0x5FC9, PID: 0x0063)
• Cross-platform support using nusb
• Asynchronous communication with Tokio
• Automatic device discovery and connection management

📊 ADC Data Acquisition

• Real-time voltage, current, and power measurements
• Multiple sample rates (1, 10, 50, 1000, 10000 SPS)
• Temperature monitoring
• USB data line voltage measurements (D+, D-)
• USB CC line voltage measurements (CC1, CC2)

⚡ USB Power Delivery Support

• Capture and parse USB PD messages
• Connection event detection
• Full PD message parsing using the usbpd crate
• Support for source capabilities and control messages

Components

km003c-lib

Core library providing device communication and data parsing.

km003c-cli

Command-line tools:

• adc_simple - Basic ADC data reading
• pd_monitor - Real-time PD message monitoring

km003c-egui

GUI application with real-time plotting and live status display.

Python Bindings

Python bindings for parsing KM003C data structures (no async device communication).

Quick Start

Prerequisites

• Rust 1.89 or newer
• USB access permissions (udev rules on Linux)
• POWER-Z KM003C device

Installation

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

Linux USB Permissions

On Linux, you need to set up udev rules to allow non-root access to the device:

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

Note: The udev rules use the modern uaccess tag approach recommended for systemd systems. This provides secure, dynamic access to logged-in users without requiring overly permissive modes or group membership. The file is numbered 71-* to ensure it's processed before systemd's 73-seat-late.rules. See the Arch Wiki on udev for more details.

Usage Examples

ADC Reading

cargo run --bin adc_simple

PD Message Monitoring

cargo run --bin pd_monitor --frequency 1.0

GUI Application

cargo run --bin km003c-egui

Python Bindings

# Install in development mode
uv run maturin develop

# Use the bindings
python -c "
import km003c
print(f'KM003C VID: {hex(km003c.VID)}, PID: {hex(km003c.PID)}')
rates = km003c.get_sample_rates()
print(f'Available sample rates: {[rate.name for rate in rates]}')
"

Library Usage

use km003c_lib::KM003C;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut device = KM003C::new().await?;
    
    // Read ADC data
    let adc_data = device.request_adc_data().await?;
    println!("Voltage: {:.3} V", adc_data.vbus_v);
    println!("Current: {:.3} A", adc_data.ibus_a);
    
    // Read PD data
    let pd_data = device.request_pd_data().await?;
    // Process PD messages...
    
    Ok(())
}

Protocol Research

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

The research repository contains:

• Complete protocol documentation
• PCAPNG captures and analysis
• Python analysis tools
• Reverse engineering methodology

Development Status

✅ Working Features

• Device communication and data acquisition
• ADC measurements with all supported sample rates
• USB PD message capture and parsing
• Real-time GUI with plotting
• Command-line monitoring tools

🔄 In Progress

• Additional device commands
• Enhanced error handling
• Performance optimizations

Requirements

• Rust: 1.89+
• Dependencies: See Cargo.toml files
• Platforms: Linux, Windows, macOS
• Hardware: POWER-Z KM003C device

Contributing

Contributions are welcome! Please see the research repository for protocol details and reverse engineering findings.

License

MIT License - see LICENSE file for details.

Related Projects

• km003c-protocol-research - Protocol reverse engineering
• usbpdpy - Python bindings for USB PD parsing
• usbpd - Rust USB PD protocol library

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For protocol research and analysis tools, visit: km003c-protocol-research