jaseg

jaseg, 6 months ago to kicad

At my work, I wrote #KiMesh, a security mesh generator plugin for #KiCad. A security mesh is a set of labyrinth-like traces covering an area on a #PCB to detect someone drilling or sawing through it. I'm happy to report, that you can now install KiMesh on KiCad nightly through the built-in plugin manager.

#electronics

A security mesh covering an irregular shape on a PCB. The mesh has two traces, that go around the entire area in a random fashion, covering it completely.

jaseg, 6 months ago to Electronics

Supplies for my #8seg installation at this year's #37c3 are arriving. That's 65 rolls (not meters) of LED tape.

#electronics

jaseg, 1 year ago to random

Just found this smol LCD on aliexpress, and now I want to build something with it. What would you make with it?

Link: https://www.aliexpress.com/item/1005003745628043.html

jaseg, 10 months ago to random

Today in admin news: A certain berlin club had the brilliant idea to automatically send out abuse notices whenever fail2ban notices unsuccessful login attempts in their IMAP logs. Our university chair just got their internet turned off because the uni's central IT got startled by a flood of abuse reports against our IP space. Guess what: Someone here who once held a now deleted mail account at the club still had it set up in their thunderbird, which dutifully tried to poll the inbox every 10min.

jaseg, 17 days ago to linux

So my #arch #linux just catastrophically self-destructed. I was using arch with the yubikey full-disk encryption package, when the machine hung and crashed during a system update. The machine crashed exactly after the old initramfs files were cleaned up, and before the new ones were written to disk. Since the yubkikey fde thing stores the seed ("challenge") for the luks key in the initramfs, all copies of the seed are gone now, and the data on that disk is unrecoverable.

jaseg, 9 months ago to origami

New boards arrived with silk made in #gerbolyze from a sheet of patterned #origami paper. The silkscreen covers the mostly empty bottom layer, with the top silk containing all component references. The footprint in the middle is a socket for a Würth WR-WST direct-to-board connector that I'm starting to use as a much cheaper and more convenient alternative to the offerings of Tag-Connect.

#electronics

jaseg, 4 months ago to vegan German

Die Hafermilch von Oatly wurde noch teurer, also habe ich mich entschieden, ein großes Hafermilch-Tasting zu machen. Ich habe eins von jedem Milchersatzprodukt gekauft, die mein lokaler Supermarkt im Angebot hat, und werde hier über die kommenden Tage meine Eindrücke verbloggen, wie die so in ungesüßtem Hafermüsli performen. #vegan

jaseg, 5 months ago to science

Wow this is bad. Some Italian researchers decided there wasn't enough anti-right-to-repair hardware #DRM in the world already, and developed a way to physically profile and recognize individual battery cells that can be combined with classic DRM technologies to prevent non-OEM battery cells from working inside a device, even if the classic DRM portion is circumvented. Whyyyyyy?!

https://dl.acm.org/doi/pdf/10.1145/3576915.3623179

#science #security

jaseg, 3 months ago to random

TIL that sudo, the unix command line utility, has a logo. And that logo is cursed.

https://commons.m.wikimedia.org/wiki/File:Sudo_logo.png

jaseg, 10 months ago to Electronics

For the longest time I was to cheap to get a proper soldering fume extractor for my occassional hobby soldering (not shit ones start around 500 €). After using just a PC fan for years, yesterday I finally improvised something nicer from an Ikea air purifier w/ activated carbon filter, an old carton and some leftover air hose from our air conditioner. I took before/after measurements with an Airthings View Plus on the same desk and found that this improv solution works great 😄
#electronics #diy

A desk with soldering equipment and a PCB. Next to the PCB lies the end of the thick air hose.
A graph showing PM2.5 particle density, showing a peak deep in the red zone at around 60 microgram per cubic meter.
The same graph, but tjis time it tops out still in the green zone below 10 microgram per cubic meter.

jaseg, 5 months ago to science

In case you were wondering, this is what a tray of cookies looks like on a thermal camera, fresh out of the oven (first pic) and during cooling (the other pics). The second pic shows traditional German cinnamon waffles, the others show shortcrust cookies.

The applications of thermal cameras in the kitchen are totally underrated. You can easily tell which ones are cold enough to be stacked and put into boxes.

Temperatures shown in the pictures are in Celsius.

#thermalcamera #science

A thermal image of a table with several wire racks full of traditional German cinnamon waffles cooling off. A cinnamon waffle maker is in the bottom of the image next to the wire racks.
Several wire racks of star, heart and holiday tree-shaped cookies cooling off. The hottest cookies have almost 95 Celsius surface temperature, the coldest are only 10 or so celsius above ambient temperature. The differences between the cookies at different stages of cooling are easily discernible.

jaseg, 7 months ago to embedded

Here's a neat trick for SWD/JTAG-debugging boards that use scary voltages, when you're afraid of toasting your computer: Some wonderful person on github has ported the #blackmagic firmware to those dirt cheap ESP8266 wifi modules (the cheaper old generation), so you can just plonk down an ESP-01 footprint and your target shows up on your wifi with a GDB remote exposed on a TCP port.

It's hacky as hell, but I got it to build for a stock 1MB flash module.
#embedded #electronics

jaseg, 6 months ago to random

I've got a negative review of #jlcpcb to share. For work, we needed a large PCB with a number of variations of the same component. I fought with JLC's support for over a week since they were of the opinion that the PCB contained multiple "designs", whatever that means, and ultimately cancelled my order. I went on to https://pcbshopper.com/ and selected https://elecrow.com/ from the results, who ultimately accepted the same design JLC refused, at a lower price, without any discussion.

jaseg, 10 months ago to Electronics

So I got a bit side-tracked this week and added schematic rendering to #gerbonara . As a bonus, I thought adding support for colorschemes would be nice, so I made a simple script that loads any sublime text color scheme and adapts it to schematics. I'm quite happy with the results, have a look!

#electronics

A schematic with a dark yellow and green colorscheme
A schematic with a dark turquoise and yellow colorscheme
A schematic with a light mint and yellow colorscheme

jaseg, 9 months ago to random

More #cccamp23 #carryshitolympics carrying stuff to my local post office that I can't take with me on the train.

The bicycle and trailer, but this time loaded with two large 60 by 40 by 32 cm euro boxes. The boxes have "caution fragile" warning tape and reflector tape on them and are covered with a small yellow tarp. The tarp and boxes are tied down to the trailer with a custom belt harness. Leaning on the bicycle is a small white and dark blue hiking-style backpack.

jaseg, 4 months ago to random

Today in Germany's "make people turn off cell broadcast" speedrun: They just pushed an "extreme" severity cell broadcast alert to what looks like about one quarter of the country because of... a chance of black ice. Seriously, they couldn't do a worse job at managing this infrastructure if they tried. Since its introduction about a year ago, including this one I have gotten three "extreme" severity alerts, and all three were bogus. This is how you make people disable this in their phones.

jaseg, 1 month ago to Electronics

I just found an interesting genre of weird but potentially useful chip: System support PMICs for large SoCs such as BD71805 (2$, i.MX SoCs), RK809 (2$, Rockchip SoCs) or WL2868 (50ct, Omnivison SoCs). These chips provide between 7 and around a dozen DC/DC or LDO channels with digitally configurable voltage(!) through I2C, battery charge measurement, and configurable power-on sequencing. Some even have fun bonus features such as an RTC, or a built-in audio codec(?!).
#electronics #chipofthemonth

jaseg, 11 months ago to random

We recently got a 3D printer. Naturally, I just had to improve all the headphones in the house.

If you want your own, you can download the files on thingiverse. The ears and the base are separate, so you can make a custom base for your particular headphones. The ears attach with some hot glue or superglue.

https://www.thingiverse.com/thing:6027421

jaseg, 10 months ago to random

Chatting with @janamarie about bright LEDs this weekend inspired me to finally dig up and continue an old project of mine, where I try to control one of these fun, stupidly high-power RGB COB modules from aliexpress.

jaseg, 6 months ago to Electronics

So, on that new JLCPCB colorful silk screen feature that's making the rounds atm. From what I can tell, the colorful silkscreen layers are just plain SVG files, but they encrypt them in a way that only EasyEDA and JLC can read them (and you can't). That means not only can these Gerbers never work with other vendors, you can't even export your own design from EasyEDA in a way you, yourself, can read or import in another tool. #electronics #pcb #jlcpcb #easyeda

jaseg, 1 year ago to random

Quick saturday tool review in case some of you are looking for something similar: After the contact block inside my old aliexpress T12 soldering iron aluminium handpiece (bottom) literally burned up, I had to get a new handpiece (top). I got a similar looking one, also made from aluminium. It works, is ergonomic, and its contact block is more confidence inspiring than the old one. It does, however, have a longer tip distance and it came without a tilt switch pre-installed.

jaseg, 10 months ago to random

It's kind of wild how fast this little i7-8665U in my new-ish used 1.1kg thinkpad crunches through gerbonara's unit tests. Like, the KiCad import test loads, saves and renders every footprint in the entire KiCad footprint library, and this little laptop just chugs straight through it in 5 mins or so.

jaseg, 8 months ago to Electronics

This is really cool: About ten years ago, a few friends and I built the first #Matelight, a very large display made from crates of glass bottles stacked up sideways, with adressable LEDs stuck into the bottles from the back. Now Hito Steyerl, a renowned artist, used a Matelight inspired by the actual one we hacked together back then at c-base as a part of one of her installations, called "Green Screen". Here's an article on the exhibition, and a photo:
https://www.theguardian.com/artanddesign/2023/jun/13/post-internet-artist-hito-steyerl-refusing-honours-big-tech
#electronics #art

jaseg, 6 months ago to Electronics

I bought some 5 year old, used large industrial power supplies for an upcoming project. Before turning them on, I decided to open them up to check for any loose parts. As I found out, these have a rather neat internal design. Like in any large power supply, they have an APFC circuit that feeds a couple hundred volt DC bus, which is then chopped and put through a chonky flyback transformer, whose output is then smoothed with an LC network. (1/n)

#electronics

jaseg, 8 months ago to Electronics

I guess I have finally disproven my long-held assumption that an MLCC's ESR is "approximately zero" 😅

That's four 1206-package 100V 470nF MLCCs at a cozy 102 degrees Celsius, and that's with about 2 square inches of 35u copper for cooling. #electronics

A thermal image of the same board, showing the MLCCs at a very toasty 103 degrees Celsius.