from Hacker News

All About USB-C: Example Circuits

by nevir on 9/5/23, 5:18 AM with 21 comments

• by stavros on 9/5/23, 7:42 AM

  This post gave me the idea of making a USB-C Russian roulette chip, where plugging the USB jack in on one side works fine, but the other side fries your device.

• by megous on 9/5/23, 7:07 AM

  > I’ve never done this circuit, but the way I see it, it should be enough to use two FETs, one per CC pin, both put in parallel.

  Yeah, don't do it. CC also carries BMC signalling and pull-up/downs are normally dynamic and can change at runtime after plugin.

  CH32X035 looks very interesting for playing with USB-PD. :)

• by burstmode on 9/5/23, 9:44 AM

  Every few sentences there there is a remark like "This circuit might have edge cases,... "...perfect for the majority of use cases,..". In other words: It will, at best, work on the developers table, but nowhere else. Why is somebody publishing examples that won't work in the real world ?

• by bloopernova on 9/5/23, 1:56 PM

  For testing your USB-C cables, I highly recommend the caberQU C2C: https://caberqu.com/home/20-c2c-caberqu-746052578813.html

  So many cables aren't power delivery, just USB 2 spec: If you're wondering why your phone doesn't charge quickly, the cable tester might be able to help you find the issue.