USB C to USB A hub

[LabRat 891]

Have you tested your C-A adapting cables, directly connecting to a 3.0+ spec device?
A lot of USB-C cables (of all terminations-configurations), are 1.1-2.0 cables in USB3's clothing, or 'charge only' cables, or resistor-hacked 'fast charge' cables...
The specific configuration of cable you're looking @, is wrought w/ mis-labeling and outright fraud.
You might even consider getting cheapie USB-C and USB-A (3.0/3.1/3.2) breakout boards, so you can map any cables you have/get w/ a DMM.

 

[Shrek]

It has just dawned on me that I might need USB C to USB A 3.

i.e. 5 pin USB A, not 4 pin

 

[Shrek]

Now I am at a loss, albeit a nice one

I finally got another hub that does USB C to A and used the USB C to A cable that came with it on the previous hub... IT WORKS

But what is so special about this cable? the other USB C to A (3.1) did not work.

 

[LabRat 891]

Now I am at a loss, albeit a nice one

I finally got another hub that does USB C to A and used the USB C to A cable that came with it on the pervious hub... IT WORKS

But what is so special about this cable? the other USB C to A (3.1) did not work.

(Probably)

https://www.usb.org/sites/default/files/USB Type-C Spec R2.0 - August 2019.pdf (pg 77)

IIRC, There's a lot of A-C cables that don't have the proper resistors. (Common issue w/ USB-C NVME adapters, they come w/ PoS cables, and the speeds are crap)

 

[Shrek]

I will try and get an extra cable from the people that make the good hub.

 

[Shrek]

Have ordered a cable with resistor and capacitor, now that I know the problem lies with the cable.

 

[Shrek]

Last set of cables were sold as USB 3.2 but turned out to be 3.1 and didn't work for running the hub.

For now I am reluctant to invest in more cables even if I know the right cable works (I have one such cable)

 

[Shrek]

Went to see my IT and they pulled out a handful of USB C to A cables... none worked.

Tried to contact the hub company (intpw) to try and purchase their cable (which works), but no response.

 

[LabRat 891]

Went to see my IT and they pulled out a handful of USB C to A cables... none worked.

Tried to contact the hub company (intpw) to try and purchase their cable (which works), but no response.

You might want to invest in a couple of those cheapie USB-C and USB3-A 'breakout PCBs'. -and, take a DMM to the pads/pins (to pin it out, and check resistances).

USB 3.0 Type A Female Breakout Board Module 8-Pin 2.54mm Header | eBay

Important Notes.

www.ebay.com

USB 3.1 Type-C Connector Breakout Board Female | eBay

Important Notes.

www.ebay.com

At the least, you can see if the 'good hub's cable' follows USB-IF's specifications, or not. (and, check any other cables for matching the 'good cable')

 

[Shrek]

Not a bad idea at all.

I also found this $24 hub that seems to come with the magic cable
Amazon.com: Powered USB 3.2 Hub Gen 2, JELIYEA 7-Port USB C/USB 3.0 to USB A Hub Adapter(4 10Gbps USB 3.2,1X 18W,2X 12W Fast Charging for Phone) 3.3ft Cable USB Splitter with 30W Power Adapter for Laptop/MacBook : Electronics

 

[Shrek]

You might want to invest in a couple of those cheapie USB-C and USB3-A 'breakout PCBs'. -and, take a DMM to the pads/pins (to pin it out, and check resistances).
View attachment 342245View attachment 342243

USB 3.0 Type A Female Breakout Board Module 8-Pin 2.54mm Header | eBay

Important Notes.

www.ebay.com

View attachment 342244

USB 3.1 Type-C Connector Breakout Board Female | eBay

Important Notes.

www.ebay.com

At the least, you can see if the 'good hub's cable' follows USB-IF's specifications, or not. (and, check any other cables for matching the 'good cable')

Much appreciated, ordered.

Who would have imagined a cable could be so complicated; progress is slow.

 

[bug]

Much appreciated, ordered.

Who would have imagined a cable could be so complicated; progress is slow.

Blame USB specs for being so permissive

 

[Shrek]

Breakout boards got here and so I could make measurements

• A 'normal' USB C to A cable has a 56 kΩ pull-up resistor between A5 and 5V, no pull-down resistor
• The magic USB C to A cable has a 5.1 kΩ pull-down resistor between A5 and GND, no pull-up resistor

The specs USB Type-C Spec R2.0 - August 2019.pdf seem to include both

P77 USB Type-C to USB 3.1 Standard-A Cable Assembly Wiring
"Pin A5 (CC) of the USB Type-C plug shall be connected to VBUS through a resistor Rp (56 kΩ ± 5%)"

P86 USB Type-C to USB 3.1 Standard-A Receptacle Adapter Assembly Wiring
"Pin A5 (CC) of the USB Type-C plug shall be connected to GND through a resistor Rd (5.1 kΩ ± 20%)"

So are both the cables to spec? (only the second one works in my application) or should I be trying an adapter?

 

[bug]

Breakout boards got here and so I could make measurements

• A 'normal' USB C to A cable has a 56 kΩ pull-up resistor between A5 and 5V, no pull-down resistor
• The magic USB C to A cable has a 5.1 kΩ pull-down resistor between A5 and GND, no pull-up resistor

The specs USB Type-C Spec R2.0 - August 2019.pdf seem to include both

P77 USB Type-C to USB 3.1 Standard-A Cable Assembly Wiring
"Pin A5 (CC) of the USB Type-C plug shall be connected to VBUS through a resistor Rp (56 kΩ ± 5%)"

P86 USB Type-C to USB 3.1 Standard-A Receptacle Adapter Assembly Wiring
"Pin A5 (CC) of the USB Type-C plug shall be connected to GND through a resistor Rd (5.1 kΩ ± 20%)"

So are both the cables to spec? (only the second one works in my application) or should I be trying an adapter?

View attachment 343810

Of course they do, it's in the name. "U" stands for "universal" **double face palm**

 

[LabRat 891]

Breakout boards got here and so I could make measurements

• A 'normal' USB C to A cable has a 56 kΩ pull-up resistor between A5 and 5V, no pull-down resistor
• The magic USB C to A cable has a 5.1 kΩ pull-down resistor between A5 and GND, no pull-up resistor

The specs USB Type-C Spec R2.0 - August 2019.pdf seem to include both

P77 USB Type-C to USB 3.1 Standard-A Cable Assembly Wiring
"Pin A5 (CC) of the USB Type-C plug shall be connected to VBUS through a resistor Rp (56 kΩ ± 5%)"

P86 USB Type-C to USB 3.1 Standard-A Receptacle Adapter Assembly Wiring
"Pin A5 (CC) of the USB Type-C plug shall be connected to GND through a resistor Rd (5.1 kΩ ± 20%)"

So are both the cables to spec? (only the second one works in my application) or should I be trying an adapter?

View attachment 343810

Related?

All About USB-C: Resistors And Emarkers

If you’ve been following along our USB-C saga, you know that the CC wire in the USB-C cables is used for communications and polarity detection. However, what’s not as widely known is th…

hackaday.com

USB Type-C connector: Rp, Rd, and Ra termination resistors

What is the purpose of Rp, Rd, and Ra types of termination resistors in the USB Type-C connector? - A downstream facing port (DFP), such as a host computer, exposes pull-up terminations, Rp, on its CC pins (CC1 and CC2) - An upstream facing port (UFP), such as a peripheral, exposes pull-down...

community.infineon.com

edit: looks like the "magic" cable, is IDing itself as a 3A cable.

 

[bug]

Strange, I always thought up/downstream is dictated by whether the connector is male/female. But if it's electrically coded, then I guess a female connector can be either up or down. Seems whacky.

 

[Shrek]

Plan now is to just get a USB Type-C to USB 3.1 A Adapter which should have the right resistor according to the specs.

 

[Shrek]

SUCCESS!

The USB C to A adapter works!

I remain amazed that a USB C to A cable is speced quite differently from a USB C to A adapter.

It was a long and winding road; what put me off the scent was having a 'magic' cable that was wired as an adapter.

 

[LabRat 891]

SUCCESS!

The USB C to A adapter works!

I remain amazed that a USB C to A cable is speced quite differently from a USB C to A adapter.

It was a long and winding road; what put me off the scent was having a 'magic' cable that was wired as an adapter.

OTG

USB On-The-Go Things