What is KVMego?

KVMego is a do-it-yourself, modular KVM switch designed to overcome the limitations of commercial off-the-shelf solutions. At its core, it's a highly customizable keyboard/mouse switch that provides advanced features not commonly found together.

Key Features:

• Modular Architecture: The main control unit for the keyboard and mouse is separate from the video switches. This allows you to use your existing video switches or build a custom solution tailored to your specific monitor setup, drastically reducing cable clutter.
• Undetectable Switching: Unlike most KVMs that physically disconnect and reconnect USB devices, KVMego maintains a persistent USB connection to all computers. This makes the switching process completely invisible to the operating systems, preventing device detection delays and issues.
• Integrated Mouse Jiggler: A built-in mouse jiggler can be toggled for any connected computer, both active and inactive. This feature simulates subtle mouse movements to prevent systems from entering sleep mode or locking the screen.
• Hidden Controls: All switching and jiggler functions are controlled via hotkeys (double-pressing Scroll Lock), meaning there are no external buttons or LEDs required. The unit can be completely hidden from view for a cleaner desk setup.
• Cost-Effective & Accessible: The design is based on custom PCB as well as readily available development modules for the ATMega2560 and CH9350L chips, eliminating the need for high-precision SMD soldering and making it accessible for hobbyists.

Why Build KVMego?

Commercial KVM switches often force compromises. They are typically monolithic units that combine video and USB switching, leading to a mess of thick, unwieldy cables. Finding a model with the perfect combination of features—like proper EDID emulation, hotkey support, and the right number of display ports—is nearly impossible.

The biggest drawback, however, is that most switches simply disconnect your keyboard and mouse from one computer and reconnect them to another. This is easily detected by the OS and can be disruptive. Furthermore, features like a mouse jiggler are almost never included. KVMego was created to solve these problems by giving you full control over a flexible, feature-rich, and affordable solution.

How Does It Work?

To avoid the complexity of implementing a full USB stack, the KVMego design uses CH9350L ICs. These chips act as dedicated USB HID host controllers, converting USB keyboard and mouse data into simple UART packets. The system uses one "master" CH9350L for the keyboard/mouse input and up to three "slave" chips for connecting to the computers.

An ATMega2560 microcontroller serves as the brain of the operation. It reads the UART data from all CH9530L chips, processes the control sequences initiated by the user (via hotkeys), routes the keyboard/mouse data to the selected computer, and generates the random movement patterns for the mouse jiggler function. The firmware is written in plain C, making it straightforward to modify or extend.

Video switching is handled by simple on/off signals sent from the control unit, which can be used to trigger relays, RF transmitters, or any custom video switch solution you devise.

Disclaimer: The Bill of Materials (BOM) included in the KiCad project files is auto-generated and may not be fully complete or accurate. Please verify all components and quantities against the schematics before ordering parts.

Please refer to the GitHub repo for the latest updates.