alt Hacker News> To my surprise, two of the USB-C pins were being used as a CAN bus (which smells horribly noncompliant).
Oh god that's awful. Why would anyone in their right mind do this?
Replies
mrheosuper • today at 3:35 AM
As long as it's not intended for user to plug in, it's fine. Many other vendors also do that.
tverbeure • yesterday at 8:08 PM
Mining rigs were using USB-C to transport PCIe x1 by the truckload. Because USB 3.0 cables are dirt cheap and are capable of transporting signals at PCIe x1 data rates.
fragmede • yesterday at 5:19 PM
Cost. It's a clever hardware hack that saves money, and 1 cent saved over 100 million units is $1,000,000!
USB-C actually has pins dedicated to application/debug use (SBU1 and SBU2). "SBU1 and SBU2: these are low-speed lines used only for Alternate Mode and accessory mode. For example, with DisplayPort, AUX+ and AUX– transmit over the SBU lines. For audio adapter accessory mode, these lines are used for the microphone input and analog GND."