Help
Install
Nothing to install to
Unplug every cable. Hold the button next to USB1 (USB3 for the mouse-side chip) while you plug that port into this computer, then press Install.
A flash stopped partway
Each chip's download mode is in ROM (memory no flash can overwrite), so a flash that stops partway never locks the chip out. Hold the button again, plug the port back in and press Install.
Which computer do I install from?
Any computer with Chrome or Edge. Install the main chip over USB1, unplug it, then the mouse-side chip over USB3.
This browser can't talk to your box
Open the page in Chrome or Edge on a computer. The dashboard reaches the box through Web Serial (browser access to serial ports).
This page isn't secure
Open the dashboard from https://medius.k4tech.net/dashboard.
Connection
This computer can't see your box
Plug USB2 into this computer. A box never set up needs the installer first.
The box isn't answering
Check USB1 is plugged in too.
The browser needs one more click before it asks
Press Retry.
Another tab or program has this box open
Close it. Only one program at a time can have the box open.
This computer can't read from the box
Unplug USB2 and plug it back in.
Mouse and keyboard
My mouse doesn't move
Connect the box on the dashboard: Overview offers Allow imperfect when the device needs it.
A device doesn't clone, or misbehaves
Check Devices for a setting it needs. If none helps, send its USB Device Tree Viewer text in a support ticket on Discord.
My Logitech mouse feels delayed, or runs at 125 Hz
Connect the box on the dashboard: Overview offers the Logitech fix. Press Force 1000 Hz and give the box up to a minute to restart.
My box has no Options
My Razer 8K mouse runs at 125 Hz
Plug it into the PC directly, set it to 8000 Hz in Razer Synapse, then plug it back into the box. Through the box it runs at 1000 Hz.
Can one box take a mouse and a keyboard?
Only through one receiver that carries both.
Software
Why doesn't my software work with Medius?
Medius uses a different control protocol (the commands software sends the box) from the stock MAKCU firmware. Software written for the stock firmware needs its developer to add Medius support. Libraries for Rust, Python, C and C++ are in the docs. The AI access page serves the docs to coding agents.
Does my software need updating when Medius updates?
Only when a release changes the protocol. The release notes say so.
Which baud rate do I set?
6,000,000, fixed. The libraries set it.
Update
Too old to update from here
One-click update needs v3.2.0 or later. Set the box up once with the installer. After that it updates in one click.
How does an update work?
With USB2 in this computer and USB1 and USB3 as they are, the Update page updates both chips, or either alone. Each chip writes the new firmware beside its current one, then boots the new one. The mouse-side chip's copy goes through the main chip. If a chip's new firmware won't run, the chip boots its old firmware.
The box came back, but not on the version sent
The chip kept its old firmware. Update again.
Newer firmware
This box speaks a newer protocol than this page. Reload the page. The Flash page can still flash it.
How do I go back to an older version?
On the Flash page, choose Older release and pick the version. Over USB2 both chips take it at once. With a chip's button held, flash the main chip, then the mouse-side chip. Versions before v3.2.0 aren't listed: this page can't connect to a box running one. With Image set to Factory, the flash also clears your settings.
Windows
My PC blue-screens
The Medius library fixed this in v3.4.2. Update the software you use with the box. For software on an older library, uninstall the WCH CH343 driver that Windows Update installs and use Windows' built-in usbser.sys driver.
Medius
Why use Medius?
It clones your mouse or keyboard to the PC byte for byte, media keys included. It gives developers an open protocol with tools the stock firmware lacks, such as motion mirroring.
Is Medius free?
Yes, and it stays free, updates included.
Do I need to install drivers?
No. Windows, macOS and Linux already have the serial driver the box uses.
Which operating systems work?
The dashboard runs wherever Chrome or Edge runs on a computer. The libraries support Windows, Linux and macOS.
Does Medius support controllers?
Not yet. Controller support is planned.
Is Medius open source?
The libraries, this site and the dashboard are. The firmware isn't.