TL;DR
A blog report describes modifying the firmware of a €40 Cable Matters USB-C hub so it responds to Nintendo-specific USB-PD messages from a Switch 2. The author says the work got the hub further through the docking process, but the supplied account stops before reporting a finished, tested TV-mode result or broad compatibility.
A reverse-engineering project has modified the firmware of a €40 Cable Matters USB-C hub to respond to Nintendo-specific messages exchanged when a Switch 2 connects to its official dock. The report says the hub already handled charging and DisplayPort setup, but lacked the additional handshake the author identified as necessary to continue docking; the supplied account does not establish that the modified hub produced a working TV-mode picture.
Get the latest gadgets delivered free with Prime
- Fast, free delivery on millions of items
- Prime Video, Amazon Music and more included
- Member-only deals all year
The author, writing on blog.nozomi.space, began investigating because the official Switch 2 dock felt bulky and fragile for travel. The selected 7-in-1 hub supports USB-C power delivery and video output. With its original firmware, the console negotiated power, entered DisplayPort Alt Mode and configured a DisplayPort pin assignment, but the author reported no TV mode or picture. That led to the hypothesis that DisplayPort setup alone was not sufficient.
To compare the devices, the author used a WITRN K2 USB-PD sniffer to capture traffic from the official dock. The capture showed the dock advertising both the DisplayPort service identifier and Nintendo’s own identifier. The Switch entered Nintendo mode before DisplayPort mode, then exchanged a sequence of vendor-defined messages with the dock. The author said the purpose of most of those messages was unknown.
The hub contains a VL103 USB-PD controller with an 8051 microcontroller, according to the report. The author added about 540 bytes of 8051 code to erased space in its firmware, creating a responder for Nintendo’s messages while leaving the existing power-delivery code in place for other traffic. The post describes a step-by-step patching process, but the material supplied here ends as the author begins listing changes and results; it does not provide a complete final test account.
A Cheaper Travel Dock, If It Works
If the approach produces reliable video output, it could offer Switch 2 owners a smaller, less expensive travel setup than carrying the official dock. It also illustrates how a USB-C accessory can appear technically capable—supporting charging and DisplayPort—yet fail because a device expects additional communication beyond standard connection setup.
The report is not evidence that any generic hub will work, or that this particular model is a ready-to-use replacement. The change requires firmware reverse engineering and modification, rather than a plug-and-play setting, and the account does not establish whether the resulting setup is stable, safe across usage conditions, or compatible with other hubs. Readers should treat it as an individual technical investigation, not a consumer recommendation.
Products Worth Considering
Apple Watch SE 3 GPS 44mm Smartwatch
Bose QuietComfort Ultra Earbuds (2nd Gen), Wireless Noise-Cancelling Earbuds with Immersive Audio and Wireless Charging Case, Black
Apple iPad 11-inch (A16), 128GB, Wi-Fi, Silver
As an affiliate, we earn on qualifying purchases.
The Dock’s Extra USB-C Handshake
The author’s starting observation was that the unmodified hub could charge the console and negotiate DisplayPort Alt Mode, but did not trigger TV output. The official dock’s captured traffic supplied a clue: it identified itself using Nintendo’s USB-PD vendor identifier as well as advertising DisplayPort. That sequence suggested that Nintendo-specific vendor messages were part of the process.
The report says the author dumped and patched the VL103 controller firmware using fwupd’s VLI support, with a device-specific quirk added for the hub. Ghidra, an 8051 assembler and the uCsim simulator were used to inspect and test the firmware against captured traffic. The author also credited Claude and GPT with helping analyze disassembly and captures. These details describe the author’s workflow; they do not independently verify the method or its results.
““With the stock firmware the Switch does get surprisingly far.””
— The project author
Compatibility and Video Results Remain Unclear
The supplied source does not show the completed version-by-version test results, confirm that the modified hub ultimately displayed a picture, or report whether the Switch 2 entered TV mode reliably. It also does not say whether other hub models can be adapted, how the modified hub performs over extended use, or whether the patch affects charging, heat or other functions. The author says most Nintendo vendor-message commands remain unexplained, so the exact purpose of the full handshake is not established by the report.
The account documents an individual modification, not a controlled compatibility test or independent review. No Nintendo statement or third-party verification is included in the supplied material.
Full Patch Tests Are the Next Step
The next useful evidence would be a complete account of the firmware changes and their results, including whether the hub consistently produces TV output after the Nintendo-message responder is added. Tests across repeated connections, power conditions and the hub’s other ports would help clarify whether the modification is dependable. Until those results are documented, the project should be understood as reverse engineering in progress, not a confirmed replacement for the official dock.
Key Questions
Did the €40 hub successfully display the Switch 2 on a TV?
The supplied report does not confirm a finished video test. It describes the original hub failing to produce TV mode and then explains the firmware responder, but the provided text ends before giving a complete result.
Why did the unmodified hub fail?
According to the author, it could negotiate power and DisplayPort Alt Mode but did not proceed to TV output. A capture from the official dock showed Nintendo-specific USB-PD messages in addition to DisplayPort setup, which the author identified as a likely missing part of the process.
Will this work with any USB-C hub?
No broad compatibility is established. The project modified firmware in one Cable Matters 7-in-1 hub with a particular VL103 controller; the report does not show that other hubs have compatible hardware or firmware.
Is the modification plug-and-play?
No. The described work involved capturing USB-PD traffic, inspecting controller firmware and writing a small 8051 responder. The source presents it as a technical reverse-engineering project, not a simple accessory setting.
Source: blog.nozomi.space
