-1
\$\begingroup\$

I have a keyboard that uses a USB 2.0 cable to connect to the computer. I would like to remove the current USB 2.0 cable and replace it with a USB C receptacle. The goal is to be able to connect the keyboard to the desktop with a male to male cable (USB C to USB A or C).

My problem is that I cannot find any material discussing the wiring of a USB C receptacle to a USB 2.0 pin out.

In the USB C spec (Section 3.5.2) it illustrates how to wire a USB 2.0 cable with a USB C plug and a USB A plug. Does wiring a USB C receptacle differ from wiring a USB C plug? In other words, can I connect the S/GND/D+/D-/V pin out from my keyboard to a USB C receptacle following Table 3-13 in the spec?

Please let me know if I need to clarify further! I am usually on the software side of things.

EDIT

USB 2.0 pin out from keyboard to USB C female receptacle pics

keyboard pinout usb c female

\$\endgroup\$
1
  • \$\begingroup\$ Nice photo BTW! \$\endgroup\$
    – Ale..chenski
    Commented Jul 10, 2019 at 6:49

1 Answer 1

Reset to default
0
\$\begingroup\$

If you are fitting an old style USB 2.0 device with new Type-C connector, here is the answer

However, Type-C to Type-C cables are thick, stiff, expensive, and may fall off from a device that is a subject of frequent moving by user. There is a reason why keyboards and mice have non-detachable cables. To use Type-C host ports, you will be much better off if you replace your Type-A plug on your existing flexible cable with Type-C plug. The plug has to have 5.1k pull-down resistor on one of CC pins. Most DIY Type-C plugs offer pre-fabricated pads for this, like in the pictures below:

enter image description hereenter image description here

\$\endgroup\$
6
  • \$\begingroup\$ I appreciate your concern on durability. It is still unclear to me whether the answer you linked covers wiring the receptacle (not the plug), or whether they are wired the same way regardless. \$\endgroup\$
    – Jtaks
    Commented Jul 9, 2019 at 14:01
  • \$\begingroup\$ Yes, the linked answer is related to a question about wiring the Type-C receptacle. On receptacle side you need two pull-down resistors, for each CC pin, although people think that the CC pins can be tied together for USB 2.0-only connector. If making a plug, only one resistor is needed. \$\endgroup\$
    – Ale..chenski
    Commented Jul 9, 2019 at 20:57
  • \$\begingroup\$ Ah it's all starting to make sense now. Thank you for your patience. Where does the choice to use 5.1k resistor on each CC pin come from? The spec mentions 56k in the cable but this is slightly different. \$\endgroup\$
    – Jtaks
    Commented Jul 10, 2019 at 5:31
  • \$\begingroup\$ @Jtaks, 5.1k comes from specs, it is a pull-down. 56k/22/10k also come from specs, these are the host-side pull-ups. \$\endgroup\$
    – Ale..chenski
    Commented Jul 10, 2019 at 6:48
  • \$\begingroup\$ Something like this looks like it would be perfect for my use case. How ever I am unsure where I would connect the shield pin from the keyboard. Would I wire it to ground? From the linked item's schematic it looks like it is just left unconnected. \$\endgroup\$
    – Jtaks
    Commented Jul 12, 2019 at 2:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.