Total Time Spent: ~16 hours!!
June 11th: Started working on the schematic!
Opened up KiCAD and, after looking through some online references, like the onboard guide, started to place components.
However, I soon realised that: 1. KiCAD does not have all the components that I would require in its library, and 2. Also, the board would require PCBA.
So instead, I shifted to EasyEDA.
I added all the components that best fit my requirements and started wiring them, but when trying to rotate one component, I accidentally reloaded the page, so all progress was lost (learned that EasyEDA does not auto-save your work the hard way) :(
Now I am downloading the desktop app and will continue with the schematic tomorrow!
Time spent: 2 hours
June 13th: Almost finished the schematic!
Decided to move away from EasyEDA because all of the UI and the keyboard shortcuts were different, and I couldn't get the hang of them. So I opened up KiCAD again and started the schematic from scratch. I used the 16-pin USB C ports schematic and, after some research between FE1.1s and SL2.1A, chose FE1.1s as the USB 2.0 hub controller!
I opened up the FE1.1s datasheet and then routed each pin to where it specified. I left the config and LED pins alone for now, and will get to them later on after researching more about what they are supposed to do!
And I also routed the power pins on the hub and ports with 10uF capacitors to ground and the CC pins on the USB-C ports through 5.1kΩ resistors to ground.
Time spent: 1.5 hours
June 14th: Finished the ports part of the schematic!
Looked at lots of USB-C hubs schematics and used them as a reference to modify my own!
- Powered each of the ports with direct 5V from the upstream USB-C.
- Added 2 decoupling capacitors on the 5V.
- Added a crystal.
- Routed the config pins using those schematics!
Also edited the resistor and capacitor values to show their actual values (e.g., 10k or 10uF) instead of Resistor
.
And routed the shields to ground.
Time spent: 1 hour
July 21st: Finished Schematic + PCB!
Finally got motivation again to work on this! I decided to scrap my KiCAD schematic and start over from scratch in EasyEDA. I also did some research and decided to replace the FE1.1S with a SL2.1A USB 2.0 hub controller!
I am going to use a USB-C port for the main IN receptacle, and then have 2 USB-C and 2 USB-A ports in the hub! And an LED to show if the connection works!
I opened up the datasheet for the SL2.1A and got to work!
It was actually pretty fast and I think I got the schematic done within 3 hours!
Then I opened up the PCB, and arranged all of my components in a small neat square! Before routing anything, I made all the D+ and D- pins differential pairs! It helped a lot! First of all, I routed the crystal because I had learned from past experience that it should get priority placement and routing! I made sure that there were no vias on any of the D+ and D- nets! And in the end, I got away with only 2 or 3 really short vias for the 5V net, and everything else on the top layer! I didn't route the ground net this time and just made a GND plane on both layers and added some vias to connect it together!
Then, finally, I added some silkscreen art and some advanced solder mask and routing layer art!! It turned out pretty good because I had a lot of empty space left on the bottom layer for it!
Total time spent: 4.5 hours
July 23rd: Completed CAD + BOM + Submission
Opened up Shapr3d on my iPad and started to make a case for the Nano Hub! I first exported the PCB from EasyEDA as .step and imported that. Then, I sketched an outline around it, offset it, and extruded the shape. After that, I created the sides and the top plate. Then I made holes in the sides for the USB slots, and also added supports/spacers to the bottom and top plates!
And I also added Nano Hub
text engraving onto the top plate!
Exported the files as .3mf (because Shapr3d only allows that in the free version :( ), and converted them to .step!
Then went back to EasyEDA, and did device standardisation, and exported all the production files! And edited the BOM to include all the prices and links!
Total time spent: 5.5 hours
July 24th: Updated schematic + PCB after feedback
Got some valuable feedback from a fellow hackclubber (@Rudy)! I had placed the decoupling capacitors in the wrong place, and my D+ and D- traces were not differentially routed! Fixed that! And also added 15pF resistors to the crystal!
Total time spent: 1.5 hours