In Case of Emergency, Plug In a KeyMod

Whether it is a stack of Raspberry Pis in a homelab or a rack of servers in a data center, techies work with a lot of machines that are built for remote access. Leaving out the keyboards and mice reduces clutter a great deal, but it can be a pain when you need to work directly at the machine. And that day will come — whether there is a networking problem or a configuration issue, there are many ways that remote access can be severed, leaving you flying blind.

Carrying a keyboard and mouse around with you everywhere to always be prepared for these situations isn’t very practical. Fortunately, TechxArtisan has come up with a much more convenient solution. It has developed a tiny device called the Openterface KeyMod that easily fits on a keychain. It plugs into a USB port and communicates wirelessly with a phone, turning it into a makeshift keyboard and mouse.

KeyMod is a compact, programmable USB and Bluetooth HID (Human Interface Device) emulator. Once connected to a target machine, it presents itself as a standard keyboard and mouse — no drivers, no special setup, just plug and play. Your phone then becomes a portable control console, complete with a virtual keyboard, trackpad, and customizable input layouts.

The concept is especially appealing for edge cases where a device already has display output but lacks convenient input. Think digital signage players, kiosks, smart TVs, set-top boxes, lab equipment, or outdoor display computers. In these scenarios, dragging out a full keyboard and mouse is awkward at best. With KeyMod, you simply plug in the device and pull out your phone.

The hardware is built around the CH9329 HID emulator chip, paired with a microcontroller, Bluetooth module, and USB interface. Because it uses a true hardware-based HID approach, the host system treats it as a native input device. This makes it broadly compatible across operating systems and hardware platforms.

KeyMod is planned in two hardware variants. One features a clever 2-in-1 flip-up connector that combines USB Type-A and USB Type-C, allowing it to work with both legacy and modern devices. The other offers a dedicated USB Type-C plug for a streamlined design.

Beyond basic keyboard and mouse emulation, KeyMod supports custom input profiles, macros, and hotkeys. Advanced modes, including keypad-style layouts and gamepad configurations, are also in the works. The team envisions uses ranging from workflow shortcuts to controlling retro games through keyboard-mapped emulators, turning a smartphone into a flexible input surface.

The mobile app is designed for Android and iPadOS, with plans to expand desktop-side control tools for Windows and macOS as part of the broader Openterface ecosystem. KeyMod is fully open source. Schematics, PCB files, firmware, software, and bill of materials will be published as the project matures, inviting the maker community to experiment, improve, and adapt the design.

The price has not yet been released, but you can sign up to receive notifications at Crowd Supply to be among the first to have a crack at owning a KeyMod.