jaseg

jaseg, 20 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, 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, 1 month ago to Electronics

RF transistor manufacturer CEL tells you in their datasheets not to lick their transistors. #electronics

https://www.cel.com/documents/datasheets/CE3512K2.pdf

jaseg, 2 months ago to Electronics

ST's latest and greatest idea is to sell the same part in the same BGA package in two subtly different pinout variants. The two variants are only distinguished by the last letter of the part number, which is at the end of the flash size and temperature variant section that does not affect the pinout in any other part they make. The package letter of the part number is identical for both variants.

Link: https://www.st.com/en/microcontrollers-microprocessors/stm32h7r3l8.html
#electronics

jaseg, 2 months ago to random

Ooof, please correct me if I'm wrong about this. If I understood it right, the authors of the paper linked below, published at NDSS (a respected academic IT security conference), sell it as an interesting research result that off-the-shelf consumer keyboards are susceptible to electromagnetic interference, and can mis-recognize keystrokes when overloaded with extreme levels of EMI.

https://www.ndss-symposium.org/wp-content/uploads/2024-15-paper.pdf

jaseg, 3 months ago to random

How not to do graphs in a scientific paper: The attached picture shows one figure from a paper with eight bar graphs. About two thirds of the bars in this picture have been cut off, and do not have any relationship anymore to the magnitude of the underlying number they are supposed to depict. These graphs are functionally useless for their original purpose, and serve as nothing more than sorted tabular data in a particularly awkward format.

#science #datavis #scicomm

jaseg, 3 months ago to 3DPrinting

I repaired my 3D printer today. It's a bed slinger, and it had a broken wire in the wiring loom going from the base to the bed. Overall, a sketchy construction in that they used mechanically fragile silicone wires along with not temperature-resistant PVC wires wrapped in a PVC jacket that's also not temperature resistant. I replaced all of them with Lapp Ölflex Heat 205, a wire that is actually rated for the temperature and mechanical stress it experiences in this application.

#3dprinting

jaseg, 3 months ago to opensource

It looks like microsoft did a microsoft again when they implemented their new fake sudo command. They basically repeated the same mistakes they made when they added that ill-advised fake curl to powershell, and stole the name of an existing #opensource utility without implementing any of the semantics, or caring about compatibility. I'm willing to attribute this to incompetence rather than maliciousness.

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, 3 months ago to Electronics

For an academic journal, "HardwareX" has some pretty wild articles of interest to #electronics #diy folks. It's open-access at https://www.hardware-x.com/current and in it there are some gems like "Arduino based intra-cerebral microinjector device for neuroscience research" or "Modification of kitchen blenders into controllable laboratory mixers for mechanochemical synthesis of atomically thin materials".

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, 4 months ago to Electronics

I'm watching a documentary on a 500 kW AM radio transmitter from the 1930ies right now. The engineers back then sure had some interesting problems to solve. Here's a link in case you're interested: https://www.youtube.com/watch?v=y1u0bHx83Vw
(1/2)

#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, 4 months ago to UX

Cursed #ux fact of the week: In the year 2024 CE, 2 k$-class precision #electronics measurement instruments are probably the last bastion of skeuomorphic #ui design. This Keysight one was delivered about one year ago new from the factory with a choice between a web frontend to a 1960ies-era text interface, and a web interface that is literally a photo of the instrument's front panel with clickable buttons. Both are copyright 2010.

A website titled "Keysight 34465A" with keysight's logo and copyright 2010, showing two text boxes. The first box is labelled "Command", and the second box is labelled "Response history". The response history reads "Sent: System: Version? Read: 1994.0 Sent: Measure: Voltage? Read: -1.401...E-04", with the first four letters of each word capitalized, the rest lowercase.

jaseg, 5 months ago to Electronics

With both power supplies for #8seg built, flashed, and tested, #37c3 can come 😆

#electronics

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, 5 months ago to random

PSA: I will be at #37C3 and I will bring my Dymo type 1595 embossing label maker with ASCII as well as Japanese Katakana and Hiragana font wheels. If you want some labels, DM me and we can meet up. I will have a few rolls of label tape with me, but if you want a lot of labels, feel free to bring your own tape.

jaseg, 5 months ago to random

Today's award for most unfortunate research paper title goes to "SealClub: Computer-aided Paper Document Authentication". Like, what were they even thinking?! 😬

https://dl.acm.org/doi/pdf/10.1145/3627106.3627176

jaseg, 5 months ago to python

Since I needed the raw data for some science, I built a quick parser for the "IRG" file format Infiray's C200 series thermal cameras write their radiometric data in. The files basically contain a low-res preview and the original, full-resolution thermal data next to a JPEG with the visual camera's image.

You can find the python module on PyPI as infiray_irg and on github: https://github.com/jaseg/infiray_irg

#python #thermalcamera #electronics

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, 5 months ago to Electronics

Here's my #electronics component of the week: In #8seg, I'm using these solderable standoffs to mechanically mount a board. They can be used with a standard reflow process. Their footprint requires about the same space as a normal screw head. With a properly dimensioned hole, the solder connection is plenty strong in both tension and torque and you can use them to pass a few amps of current between boards as well. In case you haven't used them before, I can recommend them. They're quite handy.

jaseg, 5 months ago to Electronics

#8seg preparations for #37c3 are coming along.

#electronics #pcb #soldering

A disorderly pie of two kinds of circuit boards, some X shaped and some rectangular. The rectangular ones have an sfp board edge connector, a wr-wst debug connector, and a big m3 solderable stud. On their back silkscreen is a dithered cloud pattern.

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, 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, 6 months ago to Electronics

The boards for #8seg, a light installation I'm doing just arrived. Here's some pictures of the #gerbolyze'd bottom sides.

#pcb #electronics

An abstract fog pattern printed on the bottom side of a small circuit board using a half-tone technique.
A close-up of the first picture showing detail around the circuit board's pads, where the half-tone pattern stays clear of the pads.
A close-up shot of the second picture, showing that the half-tone pattern is based on a random scattering of points instead of some geometric pattern.