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Search - "oscilloscope"
Today at school I borrowed an oscilloscope and a few capacitors and used a circuit I made at home to just demonstrate the discharge of a capacitor, since my physics teacher asked me to teach the class about this on Friday
So it's one of those old analogue scopes, so to get a nice line I turned the speed right down and did a long exposure shot with my phone and it turned out brilliantly!31
Saw some cheapie little radio in the dollar store, bought 2 of them for reverse engineering. Powered it from my lab bench power supply as usual, and tested whether it actually works before doing anything else.. then I noticed that the tunes were actually quite catchy, so I just ended up listening.
Then I started to notice that the audio wire I was using (the one I've spent a couple of days building earlier) had intermittent audio issues where the right driver would drop out when the wire was held in certain positions. Oscilloscope probing showed that there was some sort of disconnect, with only the 50Hz noise from the power lines showing up. Opened up the connector and noticed that the ground wire had detached. An 28AWG electrical wire that was inside a jack that was meant for stress relief! Yet the copper strands must've detached one by one regardless. What do I need then, huh?! 18AWG which wouldn't even fit on the connector, only to see the strands in that eventually detach as well?! You know what, let's go fancy.. 1AWG which is meant for extremely high current applications!!
At that point I was literally shouting "FUCK!!! Why does this shit always happen to me?!! ONE FUCKING PROJECT THAT FINISHED SUCCESSFULLY, YET STILL BROKE?!!!! WHY!!!!!!"
Clearly I need some fresh air to cool down. On my way to the fast food restaurant to get some Bicky burgers. More shit, humans. One stupid driver who slowed down on me, which of all things I hate the most. GO FASTER ALREADY YOU SLOWFUCK, AND GET THE FUCK OUT OF MY SIGHT!!! Next a pedestrian with a dog.. I swear motherfucker, if that dog comes anywhere near me I'll personally turn it into fucking fricassee.
Ah and then comes the killer.. in this stupid fucking summer, all that's needed to fix any issue is a fucking stupid DESPACITO, right?! More like DeSPASTICo!! FUCK!!!!
.. Back home, rather tired. So essentially a wire that was specifically built to have high endurance broke on me. Back to Bluetooth I guess.2
I know this is just an ad, but who the fuck attaches a hard drive disk directly to a FUCKING oscilloscope?6
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
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)3
We can hide messages in images via steganography (or ZIP sewing), we can hide messages in sound via either sound-based transmission (like Morse) or waveform-based transmission (think oscilloscope art videos), we can transmit it in videos in like 300 different fucking combined forms...
Encryption isn't the ONLY way, yo. Social engineering and being a cheeky shithead can get it done too.3
Alot of hacks around here!
An extract of some of those:
-Couldn't time the shutter right when photographing lightning. Used my oscilloscope to measure its electrical influence and anytime a peak is detected, it actuates the shutter.
-Using a lock as a heatsink for a overheating display driver ic.
-Hacking two USB ports together to get more power.
-Display module was too tall with header pins. Moved its back components to the main board and soldered the module flat onto it by flowing solder down its connecting holes.
-Not me but still interesting: Back on ye olde times when paid tv contained a disruptive H or VSYNC signal only their paid tv box could filter, my electronics prof. analyzed it and built the required comb filter on his own. Even sold some on the black market.
Just scared the SHIT out of myself after accidentally shorting the live and ground connections. Piece of advice: the probe on your oscilloscope (ground) is probably shorted to the live connection on its plug. DO NOT TOUCH IT AGAINST A LIVE PCB - YOU WILL CREATE A DEAD SHORT AND A REALLY LOUD BANG. Now the whole fucking house is in darkness, it's 11pm, and I'm too scared to get to the fusebox.2
Do you randomly feel intense hatred towards people in your friend circle ?
Well I am
I have tons of friends to hang out and randomly talk about well... random things.
When it comes to more engineering related dev discussions I only have a couple friends.
One I don't speak to since he isn't very passionate about the field other than the money aspect. It's hard discussing with a person who can only see the monetary aspect of things.
Well this other guy was my only companion on this journey.. but he gave up and took on an acting career. Tbh I feel cheated. I don't have a companion / rival / anybody who I can really talk heart to heart when I get a random fun idea.
I understand how acting is on its own a pretty difficult skill but I definitely am feeling intense hatred for this fucker.
No knowledgeable guy puts himself in a situation where he has to decide between acting and electronics/programming .. and I considered this bloody motherfuck my intellectual companion.
This is what it feels like to be lonely despite having so many people around.
I'm going to work on creating a split personality. It's my only option to surviving in an engineering deprived country as mine (India).
The same country where 70% people end up engineers and most of them don't know what an oscilloscope is.1