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).

Pardon Our Interruption...

Pardon Our Interruption...

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

Pardon Our Interruption...

View attachment 342244

Pardon Our Interruption...

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