Native API
Medius is replacement firmware for MAKCU-class USB input-passthrough boxes plus an open binary control protocol.
The box sits between a USB device and a PC. Native reports from the real device (mouse, keyboard, or combo) are relayed unchanged. A program injects over a separate USB-serial link: cursor and buttons for a mouse, keys and media for a keyboard.
Drive it from any language. The Rust library is the official client.
| Property | Value |
|---|---|
| Firmware version | 3.4.6 |
| Protocol version | 9 |
| Transport | 6 Mbaud, framed-only (CH343) |
| USB ID | VID 0x1A86 / PID 0x55D3 |
| Delivery | Fire-and-forget, except QUERY → RESP, TRANSFER → TRANSFER_RESP and UPDATE → UPDATE_RESP |
Before connecting:
| Topic | Detail |
|---|---|
| Protocol version | Check proto_ver in the VERSION reply during the handshake. A value other than 9 means firmware these pages don't cover. |
| Wire format | Framed binary from the first byte. No startup baud or text mode. |
| Port discovery | Scan for the CH343's VID/PID pair. |
| Correlation | Fire-and-forget has no ack or echo. SEQ pairs a QUERY with its RESP. |