Aarub

Aarub is a compact USB 2.0 hub designed around the SL2.1S USB hub controller. The goal of this project was to create a small, practical USB hub with a combination of modern USB Type-C and traditional USB Type-A ports while gaining hands-on experience with USB hardware and PCB design.

The hub provides one USB Type-C upstream port for connecting to a computer or other USB host, along with four downstream ports for connecting USB devices:

• 2 × USB Type-C downstream ports
• 2 × USB Type-A downstream ports

The mixed-port design was chosen to make the hub useful with both newer USB Type-C devices and common USB peripherals that still use Type-A connectors.

Design Approach

The main part of the design is the SL2.1S USB 2.0 hub controller, which manages communication between the upstream host and the downstream USB ports. The schematic was designed around the requirements of the controller, including its power connections, USB data connections, and supporting components.

A major part of the project was learning how to properly design the USB connections and arrange the components on a compact PCB. Particular attention was given to the placement of the USB connectors and routing of the USB data signals to keep the connections short and organized.

The PCB was designed with the goal of keeping the board compact while still making the connectors practical to access. The Type-C and Type-A connectors are arranged to provide a useful combination of ports without making the board unnecessarily large.

What I Learned

This project helped me understand more about designing real USB hardware, including:

• Working with the SL2.1S USB hub controller
• Designing USB 2.0 data connections
• Understanding USB Type-C and Type-A connectors
• Selecting components and appropriate footprints
• PCB component placement and routing
• Managing power and ground connections
• Running design checks before manufacturing
• Preparing a PCB design for fabrication

Aarub is primarily a learning and open-hardware project, and the design files are shared so that others can inspect, modify, build upon, and learn from the design.