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USB KVM Contest 2024

2025-05-20 | iPad KVM: Creative Bridge Between iOS and Low-Level Devices

Casey Howard's innovativ e "iPad KVM" project demonstrates exceptional problem-solving in action. As a Computer Science & Mathematics student at the University of Kentucky, where every student is issued an iPad, Casey faced a challenge: accessing and managing low-level devices directly from their iPad. After discovering that the Openterface Mini-KVM lacked native iOS connectivity, they built their own bridge.

Screenshot of YouTube chat interview with Casey on iPad KVM

The Challenge

  • iOS locks down USB, preventing Arduino programming, BIOS-level control, and headless server access
  • Casey needed a way to use their iPad as a BIOS-level console for everything from Arduinos to Ubuntu servers,without Wi-Fi, external power, or bulky peripherals

The Solution: Raspberry Pi Bridge

The project's core innovation uses a Raspberry Pi in "gadget mode" as a dual-purpose bridge:

  1. Draws Power
    • Pi's USB-C port is configured to pull 5 V directly from the iPad
  2. Carries IP Traffic
    • Internal network bridge carries IP packets over the same USB-C cable
  3. Serves VNC
    • VNC server on the Pi allows direct remote desktop on the iPad,no Wi-Fi required
  4. Drives KVM
    • OpenterfaceQT on the Pi interfaces with the Mini-KVM hardware
    • iPad's VNC session streams video and sends keyboard/mouse events to any target computer

Implementation Details

  1. Raspberry Pi Configuration

    • Enable gadget mode in /boot/config.txt and /etc/modules
    • Configure USB-C for 5 V power delivery
    • Establish network bridge with static IP (10.55.0.1)

  2. Remote Desktop Setup

    • Install and configure x11vnc on the Pi
    • Auto-start VNC server on the bridge interface
    • On the iPad, connect with a VNC client (e.g., RNC Viewer) to 10.55.0.1 or pi.local

  3. Mini-KVM Integration

    • Compile OpenterfaceQT for ARM architecture
    • Plug Mini-KVM into the Pi's USB and HDMI ports
    • Power the Pi via its USB-C port

  4. Operation

    • Connect the Pi to the iPad using a single USB-C cable
    • Launch the VNC client and authenticate
    • Open the Mini-KVM interface on the Pi
    • Stream the target device's video feed and control it in real time

System Architecture

Standalone KVM Setup

Components

  • iPad (Host): VNC client and power source
  • Raspberry Pi 5: USB gadget, network bridge, and OpenterfaceQT host
  • Openterface Mini-KVM: Hardware interface for target computers
  • Connectivity: USB-C (power + network), HDMI, and USB-A cables

Impact and Accessibility

With just an iPad, a Pi, and a Mini-KVM, Casey turned everyday tablets into BIOS-level consoles, no extra gear or network needed. This solution operates entirely on iPad battery power, requires no external power or internet, and remains highly portable for field use. Casey's detailed documentation and build scripts make this approach accessible to anyone with a Raspberry Pi and an iPad.

Special thanks to Casey Howard, our Hardware Hero winner in the USB-KVM DIY Challenge 2024, for expanding the Mini-KVM's capabilities and providing an elegant workaround until native iOS support becomes available. Learn more here:

2025-05-20 | Audio Bridge Concept: Inspiring Bidirectional Sound & AI Workflows

Veera Pendyala's "Audio Bridge" concept, proven through hands-on experiments, sparked forward-thinking ideas for bi-directional audio and Jetson-powered AI on the Mini-KVM. As a Senior Software Engineer at NVIDIA with 15+ years in software engineering, Veera explored a vision: bringing host ↔ target audio, conversational AI, and home-automation workflows into the USB KVM.

Veera Pendyala, brought a forward-thinking idea to the USB-KVM DIY Challenge 2024. His concept for enabling bidirectional audio with the Openterface Mini-KVM aims to enhance remote control and AI-driven applications, particularly for single-board computers like the Jetson Nano. Veera's experiments with USB audio dongles and his interview sparked inspiring discussions about the potential for audio bridging in home automation and conversational AI workflows.

Veera discussing audio bridge ideas with Billy & Kevin

The Challenge

  • Unidirectional Sound HDMI from Mini-KVM streams target → host audio only, no pathway for host mic to reach the remote device

  • Zero-Infrastructure Goal Any solution must run without internet, external power, or bulky extras

  • AI & Automation Use Cases Veera envisions live speech to a headless device for conversational AI, remote assistance, and home-monitoring scenarios

Proposed Bridge Architecture

  1. Dual USB Sound Adapters

    • Host-side dongle captures local mic/audio
    • Target-side dongle injects that audio into the remote machine's mic jack

  2. Jetson Nano as Audio Router

    • Runs ALSA/PulseAudio to map between the two dongles
    • Hosts OpenterfaceQT for KVM control and potential AI inference

  3. Mini-KVM for Video & Control

    • HDMI carries video and target audio back to the host
    • Single USB link handles keyboard/mouse and (future) audio channels
  4. Software Channel Mapping
    • Proposes extending OpenterfaceQT to expose multiple USB interfaces
    • UI toggle for enabling host mic → target routing alongside KVM streams

Impact & Community

Veera's experiments highlight the breadth of use cases waiting to be unlocked by adding audio into the Mini-KVM ecosystem. His concepts align closely with our roadmap for AI-powered workflows, home automation, and richer remote-IT experiences.

Special thanks to Veera Pendyala for sharing his vision and inspiring our next generation of Mini-KVM features. Learn more and explore other entries on the USB-KVM DIY Challenge 2024 page:

Dive into our YouTube streaming talk, Crowd Supply Teardown with Helen Leigh, Billy R.B. Wang & Kevin Peng, to learn more about Openterface Mini-KVM and the brilliant ideas from the Contest: https://youtu.be/Tp4f_uxEo6E

2025-05-20 | Openterface Viewer: Kashall's Lightweight, Browser-Based KVM Solution

Kashall’s Openterface Viewer is a standout entry in the USB-KVM DIY Challenge 2024, offering a lightweight, open-source alternative to the Openterface_QT desktop application. This browser-based KVM interface runs entirely client-side in Chromium-based browsers and requires no installation or backend server. Designed for use with the Openterface Mini-KVM, it’s built on emerging web standards like WebUSB, WebSerial, and WebHID to provide a portable solution for managing headless devices.

Screenshot of Openterface Viewer Web Interface showing the browser-based control panel Screenshot of Openterface Viewer in action controlling a target device

Why It Matters

The early version of Openterface_QT required installation and offered only basic functionality. In contrast, Openterface Viewer:

  • Runs in-browser with no installation needed
  • Works across different systems thanks to a static deployment
  • Enhances functionality with features like keyboard input and mouse capture
  • Demonstrates the power of modern web APIs for hardware control

Key Features

  1. Install-Free Operation Works directly in Chromium-based browsers like Chrome — no software or server setup required.

  2. Client-Side Architecture Built as a static web app and hosted on Cloudflare Pages (openterface-viewer.pages.dev), the Viewer communicates directly with the Mini-KVM using:

    • WebUSB for video and control data
    • WebSerial for configuration
    • WebHID for mouse and keyboard input

  3. Lightweight and Portable Ideal for quick access across various setups — from laptops to tablets — with minimal resource usage.

  4. Enhanced Control Features Improves upon QT’s early limitations with mouse capture, keyboard input support, and a responsive interface.

Implementation

  • Codebase: Developed in TypeScript with modular design and Vite for fast builds
  • Hosting: Static deployment via Cloudflare Pages
  • Dependencies: Includes usb and serialport libraries for low-level device interactions
  • UI: Responsive web interface with live video feed, input toggles, and dynamic resolution support
  • Error Handling: Incorporates reconnection logic for handling unstable USB API behaviour, especially on USB 3.0/3.1 ports

System Overview

  • Host Device: Any Chromium browser (e.g. Chrome)
  • Mini-KVM: Connects to headless devices via USB and HDMI
  • Target Device: SBCs or servers (e.g. Jetson Nano)
  • Communication: USB (control + data), HDMI (video)
  • Deployment: Static web app hosted on Cloudflare Pages

Challenges & Limitations

  • WebUSB/WebSerial/WebHID are still experimental, and can behave inconsistently on different ports or platforms
  • Limited to Chromium-based browsers
  • Viewer development occasionally trailed rapid QT updates, though Kashall’s contributions directly influenced new features in QT (e.g. improved mouse support)

Impact

Openterface Viewer redefines plug-and-play KVM access — no downloads, no drivers, just open a browser and go. It's a practical tool for:

  • IT professionals needing portable remote control
  • Hobbyists managing SBCs and headless devices
  • Developers working across platforms without cluttering their setup

This project also highlights the growing potential of web-native hardware interfaces, paving the way for more advanced, cross-platform tools in the future.

Explore Further

Special thanks to Kashall for this elegant and forward-thinking solution in the USB-KVM DIY Challenge 2024!