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Need a USB Cable? Build One (josef-adamcik.cz)
206 points by Gedxx on Sept 3, 2019 | hide | past | favorite | 67 comments

> GX12 or GX16 4-pin aviation connector (Aliexpress) for decoration.

Aesthetics is subjective of course, but I've never really liked things that are added for decoration but have no functional purpose. It's like fake drawers on cabinets or fake pockets on shirts or blazers. In this case, I imagine that connector even adds weight to the cable for no reason at all. It's got to make it a bit uncomfortable when using the keyboard off the desk which I imagine is the purpose of the coiling.

My kind of beauty is the adminbook[1]. Everything has a functional purpose in that. Nothing is added simply because it looks pretty.

Is there a name for this kind of aesthetics?

[1] https://habr.com/en/post/437912/

Let's say you were very into mechanical keyboards and DIY boards (and I think that's a fair assumption if you're building your own cables). You might do this to let you have one cable run from your computer/monitor hub and easily switch between different keyboards with USB-C or micro/mini connectors.

What's the idea behind the key coloring on the Adminbook? (https://hsto.org/webt/2-/mh/ag/2-mhagvoofl7vgqiadv3rcnclb0.j...). I think there's a certain "it's extra bulky and ugly because it looks more functional that way" to both the Adminbook and the 4-pin industrial connector, and that's fine.

> You might do this to let you have one cable run from your computer/monitor hub and easily switch between different keyboards with USB-C or micro/mini connectors.

And the cable does have a microusb connector, but what I was talking about was the inclusion of some aviation connector right in the middle. Even the post said it was purely decorative.

> What's the idea behind the key coloring on the Adminbook?

The post on the adminbook does talk about the rationale behind the colors:

> To hit the buttons faster, different key colors are used.

> For example, the numeric row is specifically colored gray to visually separate it from the QWERTY row, and NumLock is mapped to the “6” key, colored black to stand out.

> the function keys can be pressed without Fn. These are separate keys that are even divided into groups of 4 using color coding and location.

> That is, it’s an LED above the display, illuminating the keyboard from the top. In this case, it is better than a backlight from below, because it allows you to distinguish the color of the keys.

> Indicators are color-coded.

With regards to:

> I think there's a certain "it's extra bulky and ugly because it looks more functional that way" to both the Adminbook and the 4-pin industrial connector, and that's fine.

I don't think the industrial connector itself is not functional, but rather its inclusion in a USB cable.

On the keyboard coloring scheme of the Adminbook, whether you would use it or not, it definitely can be used to distinguish different key groups. Besides the ones mentioned in the parts I quoted, there's also the light background color for the keypad buttons, the dark background color for the '0', '-', and '=' keys which are used for controlling zooming in multiple applications. The F key is where the nub for your index finger is to quickly position your hand correctly, etc.

You're already spending all this extra money to build your own USB cable when you can buy one online for $5, and you want some kind of quick disconnect that doesn't put strain on the USB port itself.

Might as well go whole hog and get something that looks badass.

Ok, you got me. The real answer is that the aviation connector looks cool and it's fun to use. That's all there is to it.

The aviation connector is a quick disconnect

It's threaded, no quick disconnect is possible and in case of accidental pulling it wouldn't protect the USB connector/socket. To add quick disconnect to a cable with some damage protection, one should add a weaker point than the USB connector, that is, magnetic contacts or a plug that needs less force to disconnect than the USB one. A bayonet connector, such as the ones used in military equipment, would meet at least the quick disconnect requirement.

Quick or not, it protects the USB port from repeated plug/unplug cycles.

Lemo-style connectors are another popular option for keyboard nerds.

As others have pointed out this kind of aesthetics can be categorized by "functionalism" and also goes with the slogan "form follows function" (https://en.wikipedia.org/wiki/Form_follows_function). Also see Adolf Loos' essay "Ornament and Crime" (https://en.wikipedia.org/wiki/Ornament_and_Crime).

I suspect the purpose is to put something in a cable that a commercial manufacturer would never put in a cable. That way, he can look at it and be reminded that "I made that", or he can brag about it when someone else sees it and asks.

There's structural functionalism and then functional structuralism, you feel me?

Some people enjoy making things look interesting or exotic, see steampunk electronics. I am guessing that such stylistic designs in electronics does not appeal to you.

The device looks interesting and I think I can find uses for it in other domains, than sys admin. I just skimmed over the article, but I can't find a price and from where to buy.

It doesn't exist, it looks like just renderings. Maybe the closest you can get is something like the GPD MicroPC. Although I don't know of anything that has some of the features on their wishlist, like reversible input/output video ports.

Doesn't the connector make it modular?

The cable? Yes but why? It's already removable from the keyboard.

You could have a setup where the other end of the USB cable is hard to reach so you can use the circular connector to swap the keyboard-side of the cable for a different style USB connector. But then why not just have a USB extender mounted to the desk in an easy to get to spot? You would need to make a bunch of variations of the USB to circular connector pigtails to plug into the main one. Seems like a lot of work for something that usually only takes a couple seconds if you have an easier to reach USB port. If the guy says the circular connector is just decorative, I'd believe him. Nothing else really makes sense.

If there's ever a need for a GX12-to-MicroUSB or GX12-to-USB-A cable, then sure, but I doubt it, and the poster specifically said it was only for decoration.


No, that's specifically a style of architecture featuring (inter alia) raw concrete external finishes, and not a catchall for things you find ugly.

You're being harsh. There's more to brutalism than the material: for instance, the style tends to visibly expose functional elements like elevator and ventilation shafts to the building's exterior.

The idea of brutalism is at least partly to avoid artifice and emphasize materials and function over ornament.

Of course, applying it to anything that's not actually architecture is analogizing.

I'd go with post-modernist electronics. Pretty much everything case-mod/gamer related.

aka taking functionalism too far

I wonder if it works at the higher USB speeds. It would be interesting to use a time domain reflectometer on that to see if the big 4-pin connector causes an impedance mismatch.

Here's a TI document on USB signal PC board layout.[1] Look at all those touchy requirements. Differential lines must be the same length, down to a millimeter or so. Stubs off to the side are bad, even stubs the thickness of a PC board. They cause reflections.

USB, despite how common it is, has tough electrical specs. USB-C (which is only vaguely related to USB A and B) is even worse.

[1] http://www.ti.com/lit/an/spraar7h/spraar7h.pdf

It's not the electrical performance that bones you - it's the emissions performance. USB stands out like a Dutch brothel in the emissions chamber if you mess up the routing or return path.

In signal integrity terms, I've found it quite robust.

USB high speed or slower is actually quite forgiving but you will eat up bus bandwidth on a range leading up to non-workability because if the minimum quality is met it will keep retrying. I've pulled off some designs without impedance matched traces with lengths beyond 40% of the signal wavelength (well into transmission line worry territory) that had no issues and helped keep production costs down.

USB-C electrically is nearly identical to USB Type-A, assuming you're talking about a USB2.0 implementation. You get the same problems on USB-C as USB3.0/USB3.1 Type-A, assuming you're talking the same speeds.

Also, despite there being relatively tight tolerances, USB controls tends to be really tolerant of not meeting specs... if only because not everyone does meet spec. I doubt that 4-pin connector causes any meaningful issues, even at USB2.0 high speed.

Probably not. Assembled a keyboard with a CircuitPython controller, used the bundled mini-USB daughterboard and soldered a short piece of micro-USB cable to connect the controller (to keep the controller side unpluggable). Frozen at random times, solved by using a whole cable straight out from the controller. The original controller used software USB, meaning 1.1 speeds, and the new controller was of course high-speed 2.0.

I like TDRs and they have a lot of uses in characterizing channels (especially with time gating). I think you could get away with much less expensive and much more friendly hardware in this case, since all you need is RL or VSWR.

This is cool, and for an art project, sensible, but USB is far to much of a pain in the rear for regular cable-making if you, "need" a USB cable. I prefer to cut my own CAT 5/6 over buying premade in a lot of situations, but that doesn't require I heat up the soldering iron.

On that tangent... I've made some CAT 5 cables using a crimping tool, but aligning all 8 wires in the correct order for simultaneous insertion into the plug is quite a bit of work. Is there a trick or tool for doing it quickly?

Probably the biggest "pro-tip" I've seen from ISP cable techs is that they tend to strip way more cable than they need to go in the connector, like two or three inches worth, align the wires, kinda bend them back and forth to get everything smoothly bending the same way (straight, ideally), and then cutting off the excess.

The easy though I've seen is some folks use RJ-45 jacks with holes in the end of the connector, so you can run this excess length right through the connector, and then the crimper cuts off the excess as well.

…seen is some folks use RJ-45 jacks with holes in the end of the connector…

What‽ Well that's going to make my once-in-a-while cable terminating experience better. I like the idea of knowing each wire made it to the contact, and being able to audit them on the outgoing side before trimming.

A quick googling says the wording to search for is "RJ45 Passthrough Connectors", then be careful because the #1 Amazon hits are not actually CAT6 connectors despite their titles, and some of the other top ones are of, let's say variable quality.

> What‽ Well that's going to make my once-in-a-while cable terminating experience better.

Believe me - you'll love it.

I bought my house in 2002 and ran Cat5e to a few places in the home (not everywhere), running 100 Mbit. Last year I decided I wanted to upgrade things to gigabit speeds, so I bought a new router, modem, and switches. I did some online checking and everything seemed to indicate that for short runs (sub-100 meter IIRC), Cat5e would work for gigabit. I didn't want to crawl back into my attic for new runs, so I tried it out.

Everything worked fine except for one run - the longest run - which spanned the width of my house (about 50-60 feet). It would only detect and run 100 Mbit - not gig. Some further testing and checking revealed that I only had 4 of the 8 wires working properly (2 pair) - and those just happened to be the ones needed for 100 Mbit! Somehow I got lucky and only lost connectivity on the other pairs. My other shorter runs all worked fine. Had that cable not failed, I would have been golden...but nope.

So I had to run a new line. I decided after some research that I would run Cat6 (couldn't afford the tools or whatnot to do Cat7 or I would have) - and I found those pass-thru connectors and crimpers. Cheap enough - bought a box of Cat6, the connectors and the crimper (plus rubber boots for the ends) and then crawled into the attic early one morning (about 4am - I live in Phoenix, and this was right at the end of "spring" going into our hot season - so it was coolest in the attic at that time) and got to work.

I spent all morning and into the afternoon up there (surprisingly, even as the day wore on and got into the 80s, it stayed relatively decent in my attic - I made sure to bring plenty of ice water along, though) - most of the time in the attic, stringing the lines, sometimes having to come down and go back up to pull lines and whatnot (using the old cable as pulling line).

The pass-thru connectors and everything made it all go much, much smoother than it would have otherwise, especially when I was terminating things after pulling the lines.

I used this cable:


Though I ended up getting the orange cable (I attached it to my roof trusses using cable clips and I wanted it to "stand out" so that anybody working up there could see it clearly - my original cable had been laying on the trusses, and it had been covered by a layer of insulation we had blown it - it's quite possible that the cable was broke at that point).

I ended up getting stranded because I wanted something more flexible while I ran it - though technically you're not supposed to use stranded cable for this kind of "run" - but for short runs (in a home, all runs are typically short) it's ok - different thing I guess if it were an office or datacenter. I also like the monoprice cable because of that plastic "cross" that separates the pairs, and works as a nice core for pulling the cable without distorting the pairs. It really was nice cable.

Then I got these pass-thru connectors:


Plus some generic boots and a generic pass-thru crimper. It made everything so much simpler. It was still a "pain" to organize the wires (color code order) and get them "just right" to go into the connector, but once in, and they passed thru - I could easily see and know they were in the right order, and that the crimp would work, unlike regular connectors. If it wasn't right, I could pull it out and try again. It was really a night and day difference from what I remember in the past. I only bought a small box of cable (250 feet - I think that's what I linked), but I still had a ton left over if I need patch cables or whatnot for later.

You won't regret it.

I've found that the first method listed works pretty well- you just have to make sure that the strands don't switch places after you cut them.

The industry standard for an automotive strip (for a multi core) behind a connector is 300-500mm

Uh what?

Do you have a link showing that? Stripping half a metre of a cable just to attach a connector seems wild.

Did you use too many zeros?

No, I’ve actually recently had designs knocked back from a harness manufacturer because I specified 250mm and they didn’t think they could make it reliable.

> Is there a trick or tool for doing it quickly?

I've made quite a few in my day and it's never been an issue. I always untwist the pairs, then with the cable in my left hand, pinch the blue pair between my left thumb and index finger. I then slide the wires in between my fingers from either side in the appropriate order using my right hand. Once I have all the wires aligned, I grasp the wires between right thumb and index finger and slide my left fingers down to the sheath. Then I work the cable back and forth. I then return my left hand to pinching the wires and trim them to length before inserting.

You should write porn.

Having made a lot of them... the only trick I know is "practice".

Untwist using a paperclip and align tighter by bending side to side and forward backward all 8 at the same time. https://youtu.be/14P1cOFM_1k

Connectors like these:


Insert the cables through it, then cut off the excess.

I suppose this is more of an aesthetic thing than a tech thing considering that a cable like this probably doesn't match the USB spec very well ;-)

Actually I'm not sure, I don't know much about the spec, but I know that USB 3 has certain pairings similar to ethernet, but USB 2 doesn't have those.

If the cable he's using is shielded by ground then I think it might be up to USB 2 spec?

Edit: Interesting mini-comparison of USB 1 and USB 2 http://ww3.microtek.com.tw/tw/uploads/faq/pdf/comparison-usb...

> Actually I'm not sure, I don't know much about the spec...

See the USB 2.0 Cables and Connectors Class Document[1], in particular, 4.10.7 Test Group '6'.

Why speculate when the USB-IF has made their standards both free and readily accessible?

[1] https://www.usb.org/sites/default/files/CabConn20.pdf

Shielding doesn't mean it meets the required impedance/attenuation for the USB frequencies. USB uses the same idea as Ethernet (differential signaling) so you can make an analogy - Ethernet requires different cable specifications depending on the speed, and it's the same with USB. And the same as with Ethernet, you can usually use a lower-specced cable for short lengths.

Interestingly, even the full speed spec (which is likely what the keyboard is running at) requires a shielded cable (which the one linked in the post isn't).

I've been trying to turn old broken micro/mini usb cables into new ones using these https://www.aliexpress.com/item/10PCS-LOT-YT2153B-Micro-USB-...

But they're a tad too tiny/frail. Anyone knows some larger micro usb connector kits ?

I'd like a USB cable with a flat right-angle low-profile soft connector. Like a USB mouse/keyboard wireless dongle, but instead of the hard plastic hardware, that's just the start of the cable. Starting with a slight angle, so it works with a row of inline USB ports. For always-in on-the-go USB cables, without the socket-destroying mechanical advantage lever of traditional connectors.

I use laptop USB ports for hand tracking cameras, an HMD, and related cruft. Frequent mobile use, and unfortunate ThinkPad port placement, has those port sockets mechanically distressed. I now have sticks which slide onto the laptop to brace the cables, but... a cleaner solution would be nice. A new laptop might have better placement, but would still need protective sticks.

Reminded me of this project: Flash drive disguised as a sawed-off usb cable.


Nice cable! I’m yet to meet someone who actually uses the hiragana layout for writing japanese.

Indeed, I don't even know any Japanese people that use the kana keys. I don't know the recent data but in 2009 there was a study that found only 12% of Japanese people used kana input.

Something that is disappointing about these keycaps is that they mostly only make these for US keyboard layouts not actual Japanese keyboard layouts. I have a Japanese keyboard that the keys were getting worn on and something like this seems like it would be a good replacement but it isn't because several of the keys that aren't letters such as shift characters on numbers and other special characters are labeled wrong for a real Japanese keyboard.

There are some Japanese layout replacement keycaps but the selection is very limited compared to how many of these stylistic kana keycaps they make for US layouts. I cringe a little bit every time I see these keycaps. I mean I get it, but still.

I couldn't find け or む on this keyboard...

Worth of note:

>USB connectors. In my case USB-Mini and USB-A but you can buy USB-Micro and USB-C too.

Sure I can buy the connectors, but soldering a USB-Micro is not exactly the same of a USB-A or a USB-Mini, let alone a USB-C.

And no, those pre-soldered to a breadboard don't count for a DIY cable.

Better build two; a backup of a special cable is always nice to have and it's much more convenient to order the parts and build both at the same time.

Sigh, whipping up a cable when needed has become something to post about? Does having stacks of pin-out diagrams and a hot soldering iron near my desk make me look old?

No, but it might make you stand out a bit from the almost entirely software focused nature of this web site.

Using paracord for sleeving is a good idea. Could be useful in practical applications.

It's very popular in the audio community for making audio cables. I used some myself to make a sleeved and braided aux cable and it turned out really nice. Gives the cable a nice feel.

Also, I'm not sure if it's the braiding or the Paracord (or both?) But it's very anti-tangle.

I also used cable with a thin flexible jacket, so it doesn't stiffen up like a twig in winter.

Is it tho?

I have paracord on my HyperX headset and it's HORRIBLE, tangles constantly. I'm considering cutting it off just to avoid the tangle.

On something that never moves, maybe, but I abhor it.

Maybe replace it? There's a huge difference in quality between what manufacturers use and the 550 paracord that was used in this project.

Paracord is usually a bit more rough than the smooth nylon that you find on lots of fancy cables.

Odd, everything I've seen (that's at least paracord-like) was less prone to tangles than regular cable.

You get that problem if the paracord isn't pulled tight enough and trimmed.

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