Live data from Hacker News

I’ve made a Cursed USB-C 2.0 device

twitter.com

1–10 of 143 posts

Re: I’ve made a Cursed USB-C 2.0 device

#2
Am I reading this right that by shorting the up and down D+ (and D-) line as one is supposed to by the spec, one essentially creates a HF stub?

Or doesn't the stub matter for signal integrity / EMI because it's only a couple of mm and fully enclosed by the shield of the plug and the receptacle?

Re: I’ve made a Cursed USB-C 2.0 device

#6

Am I reading this right that by shorting the up and down D+ (and D-) line as one is supposed to by the spec, one essentially creates a HF stub? Or doesn't the stub matter for signal integrity / EMI because it's only a couple of mm and fully enclosed by the shield of the plug and the receptacle?

The tweet with the spec talks about USB2.0 devices, so it's probably not as sensitive as higher speed 3.0+ device would be (just guessing here)

Re: I’ve made a Cursed USB-C 2.0 device

#7
post #5

I love the comment that says you could make a device that requires you to unplug and plug the other way before it works, no matter what.

At least then the insertion effort is O(1): you know in advance it will take two tries. Even that is an upgrade over pre-C USB, in my view.

Re: I’ve made a Cursed USB-C 2.0 device

#8

I feel like USB-C is cursed enough on its own. The sheer number of times I’ve had to explain to family members why just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same.

This is true of electrical power outlets (15A/20A), HDMI, schrader valves, RJ45 (this one especially!), and many other things in life, and I don't think it's very fair to pick on USB-C in this manner when it does so many other things much better than previous alternatives.

Re: I’ve made a Cursed USB-C 2.0 device

#9
post #5

I love the comment that says you could make a device that requires you to unplug and plug the other way before it works, no matter what.

I believe to properly conform to the USB specification, the device must be tried one way, tried the other way, then tried the first way again before it plugs in properly.

Re: I’ve made a Cursed USB-C 2.0 device

#10
post #8

I feel like USB-C is cursed enough on its own. The sheer number of times I’ve had to explain to family members why just because the two USB-C ports on a laptop look the same, doesn’t mean they work the same.

This is true of electrical power outlets (15A/20A), HDMI, schrader valves, RJ45 (this one especially!), and many other things in life, and I don't think it's very fair to pick on USB-C in this manner when it does so many other things much better than previous alternatives.

But USB was supposed to be the unifying connector.

Before: "Here in the back of the computer we have PS/2 ports (1 for keyboard and 1 for mouse), a parallel port, serial, 25-pin serial, game port".

Introducing USB: "Everything is USB now! Plug anything anywhere!"

USB version whatever: "Well the sockets look all the same, but you can only plug your display in here, to charge it you have to connect it here", etc, etc.

Post reply on HN