USB Wire Color Code: Nobody Will Ever Notice

A USB cable carries the analog mic and earbud audio for our bike helmets; the connectors are cheap, durable, and separate easily. I cut a 2 m “USB extender” cable (which, according to the USB guidelines, isn’t supposed to exist) near the A male connector, then wire that part to the helmet and the A female part to the GPS+voice board.

The latest USB extender cable included a surprise:

USB cable with yellow wire
USB cable with yellow wire

According to Wikipedia, there’s a standard color code for the wiring inside USB cables and yellow isn’t in the list. For this manufacturer, it seems that yellow is the new red.

In previous USB extenders the red / black wires were a slightly larger gauge than the green / white data pair, but in this cable they’re not. That might matter if one expected the cable to carry, oh, let’s say an amp of battery charging current.

23 thoughts on “USB Wire Color Code: Nobody Will Ever Notice

  1. “Any customer can have a car painted any colour that he wants so long as it is black.”

    — Henry Ford

  2. Nobody will notice? I had 4 weeks vacation that I had to take or lose, one year, at a control system company. While I was away, the wrong color wire was delivered for our vehicle interface harness and in my absence, the marketing folks told production to go ahead and use it. The customer guessed about the hook-up and inadvertently reversed the up and down commands on an electro-hydraulic scissor lift and sent a platform at full speed into the ceiling. Fortunately, no one was hurt.
    On another occasion, while I was away, marketing decide to upgrade the computers in production. We had Freedos (pre-installed) on the computers and used the counter-timer on the mobo to generate a precise15 mS programming pulses for target hardware. They used computers with Windows pre-installed and loaded my software which “seemed to work” in a command screen. However the 15 mS pulse was now +/- 300 mS due to the OS and most of the production run for that week was fried.

    1. The customer guessed about the hook-up

      Verily, hell hath no fury like that of an unjustified assumption!

      I did ring out all the conductors against a known-good USB cable, just to make sure they hadn’t permuted the connections. [grin]

      most of the production run for that week was fried

      But not, of course, the guy who decided that Windows would be fine…

  3. While that page indeed states that extension cables aren’t kosher, later (under “Compatibility”), it says they may be required: “Compliant devices must either fit within the size restrictions or support a compliant extension cable which does.” I wonder if this is a wikipedia gaffe or a USB consortium one.

    1. a compliant extension cable

      I took that to mean one of those little bitty stub cables, not a 2 m hank of wire, but I suppose once you open the door to extensions, there’s no telling what will wriggle in.

      Oh, and I use “2 m” in the marketing sense. The latest batch of 2 m cables is maybe 75% of nominal. Maybe they shrank during shipping, sort of like how wire diameters seem to tighten up a bit.

      1. I use “2 m” in the marketing sense.

        The same thing apparently happens to ovens. Our combi-microwave broke a couple of days ago (or at least the microwave part did, but the hot air part has never been stellar) and while half a decade ago I picked something out in the store and didn’t really pay any attention to the alleged capacity, this time I decided to more seriously involve the Internet for a replacement.

        As it turns out ovens love to give you a volume in liters while neglecting to mention the internal volume in cm or mm. Anyhow, for comparison’s sake I decided to check what the current oven offered since we preferably wanted a slightly bigger replacement. The manual claimed 30L (350x372x232), but upon measuring it myself, I had to conclude it was more like 26L. Let’s say it was at least 10mm less for all those measurements except potentially when measured in the most flattering spots. In practice it is more than the 26L I came up with, but certainly no more than 28L to 29L either because it doesn’t have those most flattering dimensions everywhere — not that the real volume matters, for 26L is effectively the limit of the actually usable volume. Long story short, the diameter of the turning plate seems to be the most usable metric for comparison. By the by, it turns out that Whirlpool may actually be giving out realistic liter numbers, but a check in person is still pending. Their 31L model has a 36cm turning plate while our current “30L” oven has a 31cm turning plate.

        1. I suppose I should add that the alleged internal Whirlpool dimensions are 210 x 395 x 370. But these dimensions can’t be nearly as alleged as the internal dimensions in our current microwave, because the 31cm turning plate could be 33cm at the very most while it claims to be 35cm wide — and it does reach that width for a little bit, but that doesn’t help much…

        2. the diameter of the turning plate seems to be the most usable metric

          That’s sort of like the internal cargo-carrying volume of minivans and SUVs: if you’re carrying, say, foam rubber that can expand to fill all the nooks & crannies, then you can use the rated volume. If you must carry an actual box, however, don’t plan on any

          Oh, and the Sienna has 46 inches between the wheel wells, just two inches shy of whats needed to lay a 4×8 foot sheet of plywood flat on the floor…

        3. I still question the rated volume, because it seems to assume a perfect cuboid form. Of course 350*372*232mm = 30.2L and not 30L, but by the eye I’d say there’s 1L to 2L taken out of the cuboid by, um, extensions.

          Oh, and the Sienna has 46 inches between the wheel wells, just two inches shy of whats needed to lay a 4×8 foot sheet of plywood flat on the floor…

          That made me curious what the sizes of multiplex (sometimes also triplex, but I suppose that strictly speaking only refers to plywood out of three layers or something) were here and it looks like 250x122cm. Your mentioned 4 by 8 seems to convert to 1219x2438mm, which kind of makes me wonder if we secretly get 60mm less, if you get 60mm more, or if they actually make stuff at separate measurements for the US and the rest of the world.

          (Ideally wood would primarily be “local”, by which I mean within 2000km or so, from properly managed forests, but in practice way too much of it comes from badly — if at all — managed tropical forests on the other side of the globe.)

          1. if they actually make stuff at separate measurements for the US and the rest of the world.

            Hard metric quantities are definitely creeping onto retail shelves, but hard inch dimensions still rule in some things. Fluorescent tubes, for example, have “T” diameters: a T8 tube is 1.0 inch and a T12 is 1.25. That nomenclature will probably outlive all of us.

            We (here in the US) make this so much harder than it really is…

        4. We (here in the US) make this so much harder than it really is…

          Yeah, it’s not so much that the units of measurement themselves are arbitrary, but it seems like the relations between all of the units are arbitrary as well. A foot is 12 inches, a yard is 3 feet, a stone is 14 pounds (admittedly only in use in the UK these days), etc… Those fluid ounces and gallons seem to have no relation to inches whatsoever, whereas 1L is simply 1dm^3. Maybe it’s different for you growing up with it, but if I saw the internal dimensions of an oven in inches I don’t see how you could turn that into something like gallons without a calculator — maybe if you rote-learned some kind of conversion formula I suppose.

        5. Speaking of insane systems, we use something completely nonsensical for shoe sizes. The Japanese system is so much better — plus it actually includes things like width. Unfortunately shoes never seem to come with the sensible Japanese or Mondopoint system. Even my freaking Japanese shoes only list sizes under US and EURO while leaving the included “CM” heading open, which I assume is included for the Japanese size in cm. And of course shoes never seen to tell you their width, so you’re forced to try the damn things on. (I mean, not that I wouldn’t want to try them on regardless, but I could at least discard certain models without ever trying anything on.)

          1. shoe sizes

            My head just exploded.

            But now I know what that weird foot-size-measuring-tool is called: The Brannock Device. Learn something new every day!

            Last time I went to get shoes, I picked up my usual size of the same shoe and found they were the better part of an inch longer than the shoes on my feet. Same manufacturer, same numbers, same everything, just an inch longer. Fortunately, the store had the next smaller size in stock and it ended well, but sheesh

        6. I’ve never seen one of those Brannock devices. I’ve always seen this kind of thing for length and I don’t recall what, if anything, for width.

          Btw, it only just occurred to me that the shoe-size system uses pre-metric units from the very country where the metric system originated.

          1. That rod would measure the length of the inside of an existing shoe, rather than the length & width of the outside of your foot, but I suppose there’s value in knowing “What size shoe am I wearing?” without converting from one bizarre system to another.


        7. I misunderstood. In that case I’m used to simple sliding scales that look much simpler than that Brannock device. The only real reason I see for a specialized foot measuring device is that we don’t simply use centimeters or millimeters (or inches in the US, I suppose). My tape measurer tells me that my feet are both about 26cm or 10.5 inches in a matter of seconds. Add the 1cm to 2cm of toe wiggle room and you end up with my regular shoe size of 43-44 (aka size 10-10.5 US, but don’t ask me about the difference between “regular” and “athletic”). Also note that I have no idea how much toe wiggle room is really required, since the most important factor is always the width available to my pinky toe. Having looked into this more than ever before, it seems all the more ridiculous that we’re using these stupid French inches instead of Mondopoint or the Japanese system (there doesn’t really seem to be much a difference between the two, except that mm is more of an engineering unit and cm something regular people use in daily life).

          1. much simpler than that Brannock device

            Ah, but that one doesn’t measure width or the ball of the big toe: obviously inferior technology! [grin]

            I loved to play with Brannock Devices (without knowing the name!) when the family went shoe shopping, back in the day when you went to an actual shoe store where the Nice Man measured your feet and fetched appropriate boxes from the back room. I suppose there must still be stores like that around, but now that I just buy the same shoes all the time, I’ll never know.

            What all this tells me is that standards really are important and everybody should have one!

        8. I really don’t recall; it’s been more than a decade and it was an infrequent activity to boot. I’m sure there were ways to measure all of that stuff, but it didn’t look like a massive chunk of metal; that’s all. In my mind it’s like what I linked to but with some kind of width measurer as well, but I couldn’t find a picture of something like that. Of course I don’t know if there’s a particular name other than “footmeter” for such a device.

          Btw, what’s there to measure about where a toe attaches to the foot? Do you mean as the widest point of the foot for width measurement?

          1. the widest point of the foot for width measurement?

            I vaguely recall that the shoe size you need depends on both the heel-to-toe length and the heel-to-ball distance. Something about putting the shoe’s maximum width at the right location; if your toes are more forward than usual, you need a longer shoe.

            *searches with obvious keywords*

            Ah-ha! The Brannock Device instructions are online…

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