(First, sorry for my English :_D)

I'm doing a school project and I wanted to swap a male/plug USB-C to a USB-C female/receptacle. I thought it was just soldering the cables onto the board and it's ready to go, but that didn't work.

I bought this USB-C female board: https://www.amazon.es/gp/product/B00VRAZMVE/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

If you can see, the A4, A9, B4, B9 (also Vbus) connectors don't exist, but the adapters I am also working with them they don't have any extra cables that I couldn't solder.

My problem is that I want to use a male-male USB-C cable to connect the adapter to my computer but that doesn't work in any way. As I read, the USB-C connector has some cables to communicate to the master device and provide energy, so the cables I didn't solder are the Vbus ones.

Is there any way to use this adapter with a male-male USB-C cable?

EDIT: I noticed that the board itself is capable of soldering the Vbus connectors, but in the adapter there isn't an extra cable to do that, should I put a jumper or something similar?

enter image description here


closed as unclear what you're asking by Chris Stratton, Voltage Spike, Kevin Reid, RoyC, Warren Hill Jan 13 at 10:24

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    \$\begingroup\$ although USB3 is still pretty robust considering the high bandwidths that it uses, you can't expect free-flying wiring to work: there's more to cables than just connecting their conductors. \$\endgroup\$ – Marcus Müller Jan 6 at 13:13
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    \$\begingroup\$ What are you actually trying to accomplish here? What is the board with the two ICs and what is your basis for believing that this can be connected to a USB-C connector and work? Why is the question tagged HDMI??? Generally speaking, unless you know exactly what you are doing you should stick to combining legitimate connectors and adapters. \$\endgroup\$ – Chris Stratton Jan 6 at 20:33

There are several challenges in this project. Here is the connector pinout:

enter image description here

  1. A Type-C receptacle on a USB slave device must provide 5.1k pull-downs on both CC1 and CC2 pins, separate, to inform the attached cable-host that it is a device. Without these pull-downs a Type-C host won't turn its VBUS on, and nothing will ever start.

  2. USB 2 signals must be cross-connected, A6+B6 go to D+, and A7+B7 go to D-. In this case the USB2 the USB2 link will work with both cable orientations.

  3. In a fully-compliant the USB 3 device with Type-C RECEPTACLE the connection should be done to both sides of the connector using separate muxed channels. It is done either in silicon IC inside (like in Microchip USB5926), or using a special multiplexer IC. However, a USB3 device with CAPTIVE CABLE doesn't need to have the USB3 lines duplicated, because the host side will do this function, so the cable will work in both orientations.

  4. If this is an alternate-mode Type-C device (DisplayPort video converter or something), not only all four SS pairs must be present, but the CC lines must have a PowerDelivery compliant IC to communicate the alternate device parameters and functions.

  5. and most important, the USB3 signaling is very picky about electrical quality of differential wires. The wire pairs must maintain 90-Ohms differential impedance along the entire link if they are longer than 1-2 cm, otherwise the USB channel will be unable to train it self to sufficiently low error rate, and will disengage. This is likely the most challenging part of this project.

The first two differences between captive cable and full-featured Type-C receptacle must be implemented by you. Items 3 and 4 are likely already built into your device.

To meet the fifth requirement, you might succeed if you put your new Type-C receptacle at a very short distance, and carefully solder all super-speed links using twisted pairs made of thin magnet (AWG34-38) wires.

And no, VBUS pins are not missing in the dongle, they are combined into one external pad on the little PCB.


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