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I’ve made a Cursed USB-C 2.0 device

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

#71

Post by gregmac »

avian wrote: post #48
Hnaomyiph wrote: post #4

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.

I find it funny how people used to complain about the sheer number of times they had to explain to family members exactly the opposite: "No need to ask. If you can plug it in, then it will work. Computers are fool-proof like that. No, it's not like the jacks on the hi-fi" As in, someone got a new mouse and didn't know where to plug it into their computer, when in fact there was only one DB-9 connector on the computer…

I think this was at its peak when basically every computer had only USB 2.0 ports. You pretty much could plug in anything to anything, so long as it fit. Not to say there were no issues -- USB 1.1 hubs, cable length limits -- but they were so incredibly minor compared to today.

USB 3 introduced blue plugs, complicating things slightly but still everything basically worked, and if something was operating slower than expected it was at least obvious by the color.

Then 3.1 and USB-C came out, and apparently USB-IF lots its collective mind. Now you have you pay attention to see if your ports, cables and devices are "USB 3.0" or "USB 3.1 gen 1" or "USB 3.2 Gen 1" or "Superspeed" or "Superspeed 5Gbps".. (Btw, trick question: all of those are the same thing).

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

#72

Post by daniellarusso »

chaorace wrote: post #50
Theodores wrote: post #39

Earlier quoted context omitted.

Given that this is the only practical application you have to wonder why we ever had the one way plugs in the first place.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

Also, the circuit board can be made into a connector, which is not possible with USB-C.

Lots of cool applications using that technique.

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

#73

Post by justusthane »

When I worked help desk, I once found a USB mouse that instantly killed any computer it was plugged into. Instant power off.

I also found a laptop power supply that would cause the CPU of whatever machine it was plugged into to run at 100MHz. That was a fun one to troubleshoot.

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

#74

Post by coryrc »

MauranKilom wrote: post #61
chaorace wrote: post #50

Earlier quoted context omitted.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

Assuming the structural issues are solved, isn't it literally as easy as doubling each pin in a 180° fashion and shorting each pair? What additional controller complexity would this lead to (assuming termination issues are solved)?

That is exactly how usb 2.0 (LS/FS/HS) devices are implemented with USB-C.

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

#76

Post by mindslight »

mauvehaus wrote: post #36
sneak wrote: post #8

Earlier quoted context omitted.

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.

There are actually different connectors for 15 and 20 amp devices in the US under NEMA. You do see NEMA 5-15R receptacles on 20A circuits in residential applications, but that's probably because most appliances don't require 20 amps. A 5-15 connector has two vertical prongs, a 5-20 has a horizontal and a vertical, with the special case of receptacles with a T slot that fits both 5-15 and 5-20 plugs. It goes a bit dee…

safety nit: By using a dryer circuit (30A), you've got the wrong overcurrent protection on the saw. Which means that some failure modes could overload the saw, but not trip the breaker. The proper ways to do this is to run a new 20A 240V circuit, or to incorporate a subpanel with a 20A breaker into your extension cord. I don't think the risk is severe [0], but you should at least know your setup goes against the electrical code. And that the problem would be more pronounced if you did the same thing with a 40A/50A stove outlet.

FWIW if the nameplate of the motor specifies current draw at 120V, you can likely reconfigure the motor to use 120V instead of 240V.

[0] take a look at the gauge of a dryer's internal wiring, which is regulated by UL/CE and not NEC.

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

#77

Post by rubatuga »

chaorace wrote: post #50
Theodores wrote: post #39

Earlier quoted context omitted.

Given that this is the only practical application you have to wonder why we ever had the one way plugs in the first place.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

Turns out the 24 pins of USB-C are now all used for 20Gbps USB 3

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

#78

Post by tzs »

Hnaomyiph wrote: post #4

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.

What we need is a reasonably priced dongle that you can plug into an arbitrary USB-C port and it tells you what that port supports.

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

#80

Post by buran77 »

chaorace wrote: post #50
Theodores wrote: post #39

Earlier quoted context omitted.

Given that this is the only practical application you have to wonder why we ever had the one way plugs in the first place.

Two major reasons, as far as I understand things. Firstly, reversible plugs are harder to make structurally resilient, they only become feasible cost-wise as stronger materials become cheaper and manufacturing grows more efficient. Secondly, reversible plugs are a lot more complex. Compare the 4(ish) pins of USB-A to the 24 pins on USB-C. Not all of them are strictly necessary for parity with USB-A, but you could cut…

A standard USB 3.1 type A connector has 9 pins. The reversible type C has 3 extra pins (SBU, CC, VBUS), not counting the doubling caused by making it reversible. So while the reversibility doubled the number of pins, the increased complexity of the standard itself tripled it (from 4 to 12).
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