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A nearly perfect USB cable tester

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Re: A nearly perfect USB cable tester

#171

Post by EnnEmmEss »

Gigachad wrote: post #3

The thing that has been bothering me for a while is that the USB spec allows for software detection of capabilities. You can read the emarker data and see the supported protocols, speeds, voltages, etc. But there is not standard for usb controllers to present this data to the OS. So it’s stuck in the low level firmware and never passed up. In theory we could have a popup box that tells you that both your computer and…

It's fun to see the Treedix tester come up on HN. I got one a few months back and have quite enjoyed using it. One thing which I did find interesting was that one of the cables had the emarker data lie. IIRC, the emarker data would suggested it supported much higher speeds and wattage than it did. Fortunately, the other testing screens successfully detected it only had USB 2.0 wires even though it claimed to support 40 GB/s.

Re: A nearly perfect USB cable tester

#172

Post by pseudohadamard »

bean469 wrote: post #75

Sucks that there's no USB-B support. Plenty of monitors still use it and many printers do as well

For older cables there's a guy who's posted a large list of test stats somewhere... ah, here we go, I remember the "long thin resistor" comment: https://www.cs.auckland.ac.nz/~pgut001/pubs/usb_cable.html. tl;dr, you can't go wrong with Anker. Also, there's some absolute garbage out there.

Re: A nearly perfect USB cable tester

#173

Post by ssl-3 »

dijit wrote: post #142
ssl-3 wrote: post #91

Earlier quoted context omitted.

The headphones have equivalent performance whether a USB 2 cable is connected, or a USB 3 cable is connected. The headphones themselves are not USB 3 devices; the addition of USB 3 cabling instead of USB 2 cabling would change absolutely nothing about how they work. So, no: I wouldn't expect the cable for a pair of headphones (of any price) to support USB 3. That represents extra complexity (literally more wires insi…

The Litz wire point is pretty spot on, traditional headphone manufacturers understood that cable ergonomics mattered. Somewhere in the transition to USB-C, that institutional knowledge just evaporated. Your last paragraph is depressingly accurate though. I think that's exactly why devices like the Treedix exist: the standards bodies and manufacturers clearly aren't going to fix the marking problem, so now we need tes…

> The Litz wire point is pretty spot on, traditional headphone manufacturers understood that cable ergonomics mattered. Somewhere in the transition to USB-C, that institutional knowledge just evaporated.

"I heard what you guys are planning and I talked to my financial guy. He said I have enough to put a manufactured home on some land in some desolate place like the Dakotas or central Wisconsin, as long as I keep a bit of supplemental income and live a little lower. So I'm going to do that, and take my chances on growing artisanal rutabaga to sell at farmers markets.

I've already packed up the Prius. I just stopped by to wish you kids luck with your new headphone project and tell you that I won't be back."

Re: A nearly perfect USB cable tester

#174

Post by specialist »

amelius wrote: post #7

I want one that sends a pseudorandom data stream and tells me the bit error rate.

Yes and: If a cable has any faults, of any kind.

I can't believe I'm still swapping cables and ports, trial and error, trying to determine if the cable, the port (eg iPhone's charging port), or both, are failing.

Not knowing the USB specs; I assume each head of a cable can do a loop back test, determine if can even see its other head, etc.

Re: A nearly perfect USB cable tester

#175

Post by superxpro12 »

marcosscriven wrote: post #147

I haven’t yet worked out why cheap 100W PD cables partially fail after about 6 months. They can still provide some power, but between a MacBook and official Apple power supply, they’ll keep flicking between charging and not charging.

My personal favorite is the usb-c cable that works when you rotate the connector upside-down.

Re: A nearly perfect USB cable tester

#177

Post by superxpro12 »

atoav wrote: post #157
SAI_Peregrinus wrote: post #151

Earlier quoted context omitted.

Keysight are nice enough to provide prices on their web site for all their cheaper equipment. I priced out a setup for USB 2.0 eye diagram compliance testing on their site in this comment¹ and it's more like $40,000 than $10,000. ¹ https://news.ycombinator.com/item?id=47568399

I said 10k because I think I saw a specialized product just for HDMI starting at roundabout that price bracket once mentioned in a youtube video, csn't really remember the brand, but it was relatively unknown in terms of test equipment. More generic (and flexible) equipment like the one mentioned will indeed tear a deeper hole into your pocket, but comes with its own perks.

The "certified" lab-grade stuff is so expensive because your essentially paying for someone else to certify the function for you.

There's cheaper generic VNA's that dont claim "yup, this is HDMI Ultra High Speed" that might work in the right hands.

Re: A nearly perfect USB cable tester

#178

Post by fmajid »

SAI_Peregrinus wrote: post #153
fmajid wrote: post #23

Earlier quoted context omitted.

The Treedix will tell you that, as it is a feature of the eMarker chip (no chip means 60W).

Assuming the chip isn't fraudulently added. Like in the article, some manufacturers are shady & will sell cables with e-marker chips for capabilities the cable can't actually support.

Yes, but the only way to test for something like that would be to put the rated load and see if the cable smokes. Not something a family-friendly tester would do.

Re: A nearly perfect USB cable tester

#179

Post by SAI_Peregrinus »

fmajid wrote: post #178
SAI_Peregrinus wrote: post #153

Earlier quoted context omitted.

Assuming the chip isn't fraudulently added. Like in the article, some manufacturers are shady & will sell cables with e-marker chips for capabilities the cable can't actually support.

Yes, but the only way to test for something like that would be to put the rated load and see if the cable smokes. Not something a family-friendly tester would do.

No need to check for smoke, just need to check the voltage drop between source port & sink port.

You need a >5A output power supply, two voltmeter channels (for source & sink), one ammeter channel (to sense applied load), an electronic DC load (actively cooled FET that uses the ammeter to set a constant current), a microcontroller, screen, some buttons, and software to run the whole thing. Or the manual version: Lab power supply, some USB connector breakout boards, a DC load, optionally a multimeter, a pencil, and some graph paper. Set the power supply current limit over 5A, voltage to 5V, set the DC load to 500mA, and measure the voltage at the power supply & DC load every 100mA as you increase it up to 5A load (or 3A if the cable isn't marked for 5A capability). If the sink drops more than 0.6V below the source, the cable is not compliant.

Re: A nearly perfect USB cable tester

#180

Post by fmajid »

SAI_Peregrinus wrote: post #179
fmajid wrote: post #178

Earlier quoted context omitted.

Yes, but the only way to test for something like that would be to put the rated load and see if the cable smokes. Not something a family-friendly tester would do.

No need to check for smoke, just need to check the voltage drop between source port & sink port. You need a >5A output power supply, two voltmeter channels (for source & sink), one ammeter channel (to sense applied load), an electronic DC load (actively cooled FET that uses the ammeter to set a constant current), a microcontroller, screen, some buttons, and software to run the whole thing. Or the manual version: Lab…

Right, but you can't expect a pocket sized tester like the Treedix to implement that, even if it is the USB standard test for compliance. The Treedix does measure resistance on the cable, however, so if a cable exceeds 250mΩ it would also flunk your more accurate test.
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