grahammedlin / usb-c-illegal Goto Github PK

Quick reverse-engineering of USB-C coupler and USB-extension cables purchased on Amazon.

I would like to use USB-C cables in a non-compliant way for another project. I do not believe the Type-C Specification allows any passive configuration to use a Type C receptacle. This seems to be because they could create composite 'cables' longer than guarantees about data integrity and power delivery allow. Also, you could create a Type A-to-Type A cable and collapse the universe into a black hole.

But of course you can still buy them. If reusing a USB-C cable with only one CC wire or only one set of USB 2.0 pins, they come with an amusing tag like this:

• Microchip "Introduction to USB Type-C" Appnote
• Hackaday "All About USB-C: Illegal Adapters"
• Stack Exchange "Why does a female-female coupler break the USB-C standard?"
• Type-C Specification

USB Type-C receptacle to USB legacy adapters are explicitly not defined or allowed. Such adapters would allow many invalid and potentially unsafe cable connections to be constructed by users.