A plug-and-play USB HID KVM adapter — CH9329 for keyboard and mouse control, MS2109 for HDMI capture. Driver-free, works down to BIOS, and it runs with the existing CH9329 software ecosystem.
Control any PC's keyboard and mouse over USB while watching its screen via HDMI capture — all from another PC, a script, or an AI agent.
flowchart LR
subgraph Controller["Controller PC"]
APP[software]
end
subgraph Middle["kvm-over-usb adapter"]
USBHOST[USB HOST]
DEVICE[Core Processing]
end
subgraph Target["Target PC"]
HID["Keyboard/Mouse"]
HDMI_OUT["HDMI out"]
end
APP -- USB --> USBHOST
USBHOST --> DEVICE
DEVICE -- HDMI --> HDMI_OUT
DEVICE -- USB --> HID
USBHOST -- USB --> EXT["External USB Device<br>(USB drive / HDD)"]
HID protocol transmission, driver-free
Support BIOS keyboard control
Upper computer program compatible with non-board video capture card
On-board USB-HUB chip, reduce the number of interfaces
Single MCU dual USB Device controller, reduce transmission delay
The USB-A socket, used for USB expansion of the Controller PC, can connect wireless keyboards, Mouse, USB flash drives, external hard drives, and other USB devices.
The CH9329 on this board ships at 9600 baud — its factory default.
That is deliberate. 9600 is also what most existing CH9329 software expects, so the board works with the current ecosystem out of the box: no per-unit configuration, and no changes required to any software project.
It is still the single most common cause of "the video works but the keyboard and mouse do nothing". A baud mismatch is silent: video is unaffected, host software usually reports the serial port as connected, and keystrokes simply never arrive. A green "connected" status is not proof that input will get through.
- Most of the projects listed below already default to 9600, so there is nothing to set. See the tables under Software.
DezKVM-Godefaults to 115200. Set Settings → Serial Baud → 9600; the page reconnects by itself.
These are independent community projects. None of them is bundled with, endorsed by, or supported through this board — they are listed because they work with it. Pick whichever suits you.
Every baud figure below was read out of that project's source, and the list was checked against this hardware on 2026-09-30: the CH9329 answers a GET_INFO query at 9600 and stays silent at 115200, it enumerates as CH340 1A86:7523 on the control side and 345F:2109 on the capture side behind the on-board hub, and a keyboard HID packet came back acknowledged with a valid checksum. If a project later changes its default, that date is the one to trust.
| Project | Type | Notes |
|---|---|---|
| canwdev / web-mediadevices-player | Browser (Web Serial) | Web viewer with CH9329 keyboard/mouse control, screenshots and recording. Also builds as a Tauri desktop app. |
| mofeng-git / One-KVM | Desktop + web | ch9329_baudrate already defaults to 9600. |
| sipper69 / Control3 | Windows desktop | C# laptop KVM, BaudRate defaults to 9600. |
| binnehot / KVM-over-USB | Desktop GUI | PySide client, CH9329 serial mode. |
| sjmf / kvm-serial | Cross-platform (Python) | pip install kvm-serial. --baud flag if the chip was reconfigured. Also drives CH9350L. |
| sunasaji / serial-hid-kvm | Desktop + web + API | pip install serial-hid-kvm. Preview window, browser viewer, TCP JSON Lines API. |
| sunasaji / cli-serial-hid-kvm | CLI | Front-end for serial-hid-kvm, with OCR screen reading. |
| sunasaji / mcp-serial-hid-kvm | MCP server | Lets AI agents drive the target PC directly. |
| hitmoon / guvc-kvm | Linux | guvcview-based, exposes a VNC server. |
Browser-based options need Chrome, Edge or another Chromium browser, because they use the Web Serial API. Firefox and Safari are not supported.
| Project | Type | Notes |
|---|---|---|
| tobychui / DezKVM-Go | Browser (Web Serial) | Defaults to 115200 — set Settings → Serial Baud → 9600. |
| davidkim-code / kvm | Browser / Android Chrome | NanoKVM-USB fork with a baud rate selector for DIY CH9329 hardware. |
| KaroUniform / irbis-kvm | macOS 14+ | UVC capture plus a CH9329 UART bridge, with a baud selector. |
Support is thin here. irbis-kvm is the only macOS client found, and its source is not published in that repository. Everything else is Windows, Linux or browser-based — and the browser options run on macOS only in Chromium.
You should not need this for normal use. It is only relevant if you deliberately want to change the chip's baud rate.
CH9329Test_CfgTool.exe in this repository is the official WCH tool, mirrored here for convenience:
- Version
1.4.0.0,Copyright (C) WCH 2025 - Digitally signed by
Nanjing Qinheng Microelectronics Co., Ltd., DigiCert timestamped - SHA256
FB65F3F3823407DAF473E5F329CCB825FF0E4DE31A4534043F897D1282C709C9
Prefer to download it from the vendor instead: https://www.wch.cn/downloads/CH9329_ZIP.html
Verify before running — right click the file → Properties → Digital Signatures, and confirm the signer is Nanjing Qinheng with a valid status. Or:
Get-FileHash .\CH9329Test_CfgTool.exe -Algorithm SHA256When you do run it, keep your existing wiring. With Host USB-C connected to the controller PC, the board enumerates a CH340 virtual serial port (a COM port on Windows, /dev/ttyUSB* on Linux) — select that port in the tool. No rewiring required, and do not disconnect Target USB-C.
Q: The video works, but the keyboard and mouse do nothing. What is wrong?
A: Almost always a baud rate mismatch. See Serial baud rate.
Q: Why doesn't the mouse work when the controlled end is a Linux distribution?
A: Some operating systems do not support the mouse in absolute coordinate mode. Please try switching to relative coordinate mode for operation.
Q: How to send the Ctrl + Alt + Delete key combination?
A: To send these key combinations to the controlled end, it is recommended to use the shortcut function in the Keyboard menu.
Q: What VID/PID does this board enumerate as?
A: The MS2109 capture side is 345F:2109 (UVC video, USB audio, HID) and the CH9329 control side is a CH340 at 1A86:7523. Both sit behind the board's on-board USB hub.
The documentation in this repository is MIT licensed — see LICENSE.
CH9329Test_CfgTool.exe is the exception. It is a WCH binary, redistributed
unmodified for convenience, and remains under WCH's terms.