Integrated HUB - Ethernet, USB, RS232

The Integrated HUB is a compact, multifunctional device designed to simplify connectivity challenges faced in labs and workspaces.

STATUS

Project revision 2.0 in progress as of 2025

Primarily documented on hackday.io, Integrated HUB - Ethernet, USB, RS232. This website is only meant to provide a high level overview.

In the future I'll be releasing my github repo, though there is enough documentation on Hackday to repicate this project today.

Overview

Summary

The Integrated HUB is a multi-functional device that integrates several common USB dongles into one. This device integrates a USB to ethernet NIC, a USB HUB, a USB to RS232 converter, and an unmanaged network switch into a unified simple solution. The USB to ethernet adapter has a fixed connection to port 0 of the switch. Unlike many switches and USB HUBs on the market, this device does not require an external power brick.

Why I made this?

This product was designed out of frustration working in a lab environment where USB dongles are consumed like candy by the engineer inhabitants. When debugging the DUTs at work, engineers typically need an RS232 adapter for sending debug commands, a USB to ethernet adapter to keep the DUT isolated from the larger network, a network switch if working on multiple devices, a mass storage device to bring the results back to their desk, and finally, a USB hub since most lab PCs only have one spare USB port. Scavenging these five dongles/devices takes a lot of time and cables, both of which are valuable resources in the lab. The Integrated HUB seeks to combine four of these devices into a simplified single cable solution.

Fusion 360 Drawing of Device Top view of PCB

See the below block diagram for a general overview of the core components of the system. In general, power management includes a 5V to 3V3 smps which is powered from either an external barrell jack or from the USB host. The USB to ethernet transciever is accomplished using LAN9514 from microchip. This device also provides 4x downstream USB ports. One of these ports is used by the RS232 transciever, and the remaining 3x are exposed to the user via a USB HUB. Finally, the output from the USB to ethernet transciever is piped into port#0 of a dumb switch. This was the cheapest available chip I could find on the market, the IC+ IP175G

Project Block Diagram

Future Work

Revision 2.0

I'm working on releasing revision 2.0 for this project sometime in 2025. This will be the final "official" release of the project. Revision 1.0 is very usable, but there are still a few lingering issues that must be addressed in Revision 2.0.

Errata

The full errata is documented in a spreadsheet on my github repo. I've documented the critical items that need to be addressed by the next revision.

  • Vertical Isolation - Clearance was overlooked during PCB layout, resulting in only 0.2mm of vertical separation on the basic isolation.
  • Power Delivery - Requires a correction for external 5V input to prevent USB backfeeding.
  • USB Startup Current - There's a hardware bug on revision 1.0 that causes all load switches to be enabled momentarily the second power is applied. This causes a large current inrush which trips out the host controller. This can be temporarily avoided by using less bulk capacitance, but for a proper solution see revision 2.0.

    • Reminder

    This page is intended as a high level overview of the project for full project documentaiton please see my Hackaday project page.

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    "I'm working on releasing Revision 2.0 sometime in 2025, which will be the final official release of the project. While Revision 1.0 is very usable, there are still a few lingering issues that must be addressed in Revision 2.0."