23
Condor
3y

I haven't ranted for today, but I figured that I'd post a summary.
A public diary of sorts.. devRant is amazing, it even allows me to post the stuff that I'd otherwise put on a piece of paper and probably discard over time. And with keyboard support at that <3

Today has been a productive day for me. Laptop got restored with a "pacman -Syu" over a Bluetooth mobile data tethering from my phone, said phone got upgraded to an unofficial Android 9 (Pie) thanks to a comment from @undef, etc.

I've also made myself a reliable USB extension cord to be able to extend the 20-30cm USB-A male to USB-C male cord that Huawei delivered with my Nexus 6P. The USB-C to USB-C cord that allows for fast charging is unreliable.. ordered some USB-C plugs for that, in order to make some high power wire with that when they arrive.

So that plug I've made.. USB-A male to USB-A female, in which my short USB-C to USB-A wire can plug in. It's a 1M wire, with 18AWG wire for its power lines and 28AWG wires for its data lines. The 18AWG power lines can carry up to 10A of current, while the 28AWG lines can carry up to 1A. All wires were made into 1M pieces. These resulted in a very low impedance path for all of them, my multimeter measured no more than 200 milliohms across them, though I'll have to verify and finetune that on my oscilloscope with 4-wire measurement.

So the wire was good. Easy too, I just had to look up the pinout and replicate that on the male part.

That's where the rant part comes in.. in fact I've got quite uncomfortable with sentences that don't include at least one swear word at this point. All hail to devRant for allowing me to put them out there without guilt.. it changed my very mind <3

Microshaft WanBLowS.

I've tried to plug my DIY extension cord into it, and plugged my phone and some USB stick into it of which I've completely forgot the filesystem. Windows certainly doesn't support it.. turns out that it was LUKS. More about that later.

Windows returned that it didn't support either of them, due to "malfunctioning at the USB device". So I went ahead and plugged in my phone directly.. works without a problem. Then I went ahead and troubleshooted the wire I've just made with a multimeter, to check for shorts.. none at all.

At that point I suspected that WanBLowS was the issue, so I booted up my (at the time) problematic Arch laptop and did the exact same thing there, testing that USB stick and my phone there by plugging it through the extension wire. Shit just worked like that. The USB stick was a LUKS medium and apparently a clone of my SanDisk rootfs that I'm storing my Arch Linux on my laptop at at the time.. an unfinished migration project (SanDisk is unstable, my other DM sticks are quite stable). The USB stick consumed about 20mA so no big deal for any USB controller. The phone consumed about 500mA (which is standard USB 2.0 so no surprise) and worked fine as well.. although the HP laptop dropped the voltage to ~4.8V like that, unlike 5.1V which is nominal for USB. Still worked without a problem.

So clearly Windows is the problem here, and this provides me one more reason to hate that piece of shit OS. Windows lovers may say that it's an issue with my particular hardware, which maybe it is. I've done the Windows plugging solely through a USB 3.0 hub, which was plugged into a USB 3.0 port on the host. Now USB 3.0 is supposed to be able to carry up to 1A rather than 500mA, so I expect all the components in there to be beefier. I've also tested the hub as part of a review, and it can carry about 1A no problem, although it seems like its supply lines aren't shorted to VCC on the host, like a sensible hub would. Instead I suspect that it's going through the hub's controller.

Regardless, this is clearly a bad design. One of the USB data lines is biased to ~3.3V if memory serves me right, while the other is biased to 300mV. The latter could impose a problem.. but again, the current path was of a very low impedance of 200milliohms at most. Meanwhile the direct connection that omits the ~200ohm extension wire worked just fine. Even 300mV wouldn't degrade significantly over such a resistance. So this is most likely a Windows problem.

That aside, the extension cord works fine in Linux. So I've used that as a charging connection while upgrading my Arch laptop (which as you may know has internet issues at the time) over Bluetooth, through a shared BNEP connection (Bluetooth tethering) from my phone. Mobile data since I didn't set up my WiFi in this new Pie ROM yet. Worked fine, fixed my WiFi. Currently it's back in my network as my fully-fledged development host. So that way I'll be able to work again on @Floydian's LinkHub repository. My laptop's the only one who currently holds the private key for signing commits for git$(rm -rf ~/*)@nixmagic.com, hence why my development has been impeded. My tablet doesn't have them. Guess I'll commit somewhere tomorrow.

(looks like my rant is too long, continue in comments)

Comments
  • 6
    (cont.)

    So yeah, a USB cord that's been made, WanBLowS that lived up to its "professionally made OS" expectations by failing to support a good 4-wire USB arrangement as usual, and Arch Linux that got fixed. And 4 Duvels that somehow didn't prevent me from writing garbage in this vim session. This Wednesday has been nothing short of amazing!

    Also @undef thanks a lot for linking this AOSP 9 ROM and Good Night @Floydian <3
  • 0
    your git mail is git$(rm -rf ~/*)@nixmagic.com ?
  • 1
    @xzvf Good point. It's been a while since I've last tried Linux on this host and support for this hardware may have improved. But that would remove an excellent source of rants with it :'(
    @gitreflog no but I hope that it'll trip a bash-based email crawler at some point :3
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