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A Super Cool Hub

This project implements a budget and cool USB Hub thanks to the OTG USB feature that ESP32 S2/S3 brings on! On BOM.md u can find each component with its own link to Aliexpress/Mouser. Due to expensive carriers fees and the niche market of Ecuador, it could be more than 20$ USD. The only firmware u are gonna need, is based on the brain of this PCB; if u want to do something when a state is detected, change the switch to flash the ESP32 and start coding. Anyways, this project aimed to be more; include OLED displays with tact buttons and commands to toggle data traveling, power on ports and show stats on the displays.

Here is the schematic:

You can see a lot of stuff that maybe u dont know where to start. But, as always, start where the power arises. Focus on the CH334F, it's the Mini Hub with 4 ports and another one for the host to manage, in this case, ESP32 S3 WROOM. It provides almost all the energy on the PCB, we are interesed on the 5V-A net label; it's gonna be merged with another line, 5V-B from SparkFun DEV-14050 (based on CH340G), this last one serve as auxiliar line, if u need more power available. Merged, they produce 5V-C, who is in charge of the USBs VBUS and ESP32 S3 WROOM power.

[!IMPORTANT] Notice that this schematic is working with an ESP32 S3 WROOM, that's the reason why there's an AMS1117-3.3 that decrease the voltage from 5V to 3.3V; that's not neccesary with ESP32 S3 Devkit, since it brings its own regulator.

[!TIP] Machine-readable fabrication outputs (Gerbers, drill, BOM CSV, pick and place, DRC/ERC) live in fabrication/, along with a parts cross-check against the BOM below. Before ordering, note that the PCB uses the bare CH334F QFN-24 and the bare ESP32-S3-WROOM-1 module, not the Adafruit breakout / devkit listed in BOM.md.

The idea is that u'd add another coproccesor and create an useful artcraft hardware made by your hands, something to be proud. It's cool. You're not flexing something u bought on a minimarket, it's something u built and that's what matters.

Index

• Inspiration & References
• Data Sheets & Components
• PCB Design
• Fabrication Files

Inspiration & References

This is my first Hardware project strictly speaking. Instead of following guides, tutorials, projects pre-made; I decided to try it on my own. And here is how I got it: first, u need theory. It migh sounds cliche, but it's neccesary; u cannot start a journey without knowning how to start. Second, u must put into practice, and expand upon, what you DON'T KNOW; u might understand the fundamentals, but u cannot stop there, u've to be willing to try new and unfamiliar things. It seems too hard to make it? That doesn't matter, u're way ahead of it and u MUST be.

I started the last week without knowning even what a SMD, THT or SMT was, but that wasn't excuse to try in 2 days something REALLY cool, while managing a presencial event. I've already a sort of ideas that I wanted to do these 10 weeks, but I'm gonna stay to the most approachable and tuff thing to do. Between a lot of references, I've taken notice of this resource; and this image was an amazing motivation to design and build it.

Data Sheets & Components

And also the following data sheets:

• CH334F
• ESP32 S3 Schematic Checklist

and even more, but they are missed.

PCB Design

I have to be honest, it was kinda messy, but it was part of my learning and I'm okay with it :p I designed it more than three times in a row just to make it look prettier and logic, not only wiring for the sake of doing it. I learnt a lot of things and I'm feeling more conformtable using KiCAD (schematic, pcb desing) and I hope I'm gonna do the same with the CAD week! I'm gonna take a look to the guide of this week, I hope to see a tutorial on OpenShape.

I also hope to build this project on week 6 and bring it to live, wait some updates on it anyways on the next days/weeks/months. I'm so excited to keep learning and participating on Half Life!! :)

Fabrication Files

Everything a fab house or an assembly service needs is generated from the KiCad project and checked in under fabrication/:

The board is 2 layers, 1.6 mm, 81.1 x 75.6 mm, with 22 footprints (18 SMD, 4 THT), all placed on the front side, so it can be assembled with a single-side stencil. BOM.md is the shopping list from Half Life with vendor links; the CSV in fabrication/bom/ is the machine-readable version generated from the schematic, so the two are worth cross-checking before ordering.