Mäh W.

@maehw@chaos.social
358 Followers
732 Following
3.5K Posts
👨‍💻 I am interested in wired & radio communication, DSP, (embedded) software dev & engineering, FOSS, reverse engineering, IT security, space, programmable and non-programmable bricks, old and new computer technology, robots, machine embroidery & other things. Living in 🇩🇪. Speaking 🇩🇪/🇬🇧/💻 and understanding a little bit of 🇫🇷.
Mäh W.1d ago
Fuzzy Leapfrog1d ago

Die Antwort auf meine ewige Frage "In welcher Welt leben wir eigentlich?" ist "Nicht in der selben!"

https://rp-online.de/politik/deutschland/kanzler-merz-gibt-frauen-karriere-tipps-maenner-sind-bessere-netzwerker_aid-130381277

Mäh W.1d ago
It's FOSSApr 28

Huge respect 🫡

#opensource

Mäh W.1d ago
pitch R.1d ago

👋
Ich suche Speaker*innen (explizit nicht Typen) im #ITSecurity Umfeld, bestenfalls mit und rund um #OpenSource Technologien.
Solltest du dich da sehen, aber nochnie darüber erzählt haben helfe ich auch super gerne bei der Erarbeitung einer Präsentation.

Gerne teilen fürs Hivemind!

english version below ⬇️

Mäh W.1d ago
ultrageranium1d ago

Anyone can recommend forgotten books about designing and programming text user interfaces (TUI) for consoles/terminals, also known as screen design back in the 80s?

*Not* curses or using existing libraries, but more like relying directly on ANSI/VT100 control sequences. And *no*, I'm not asking for a list of escape sequences :)

The kind of material I'm thinking of is something close to the 1989 "Programming the User Interface: Principles and Examples" by Judith R. Brown and Steve Cunningham. But focused on TUI exclusively. The more (pseudo-)code, the better.

#ansi #vt100 #terminal #tui #console

Mäh W.1d ago
datenwolf1d ago

Gibt es jemanden in meiner Bubble der mir für ein paar Tage ein Differential-#GPS / #GNSS-Gerät in Geodäsie-Qualität leihen könnte?

Bevor ich damit anfange das Katasteramt zur Vermessung und setzen von Grenzsteinen bei meinem kleinen Biotop (ich vermute der Bauer nebenan ackert da immer mehr hinein) einzubinden, will ich das erst selber ausmessen, ob das tatsächlich passiert.

Mäh W.1d ago
Jan Beta1d ago
I had some cool conversations in the #Chat64 yesterday. Plug and play chatroom cartridge for the #C64, #Atari8bit and #ZXSpectrum. Really neat project. Video coming soon(ish)! #RetroComputing #VintageComputing
Mäh W.2d ago
Christoph Stoettner2d ago
Die Schule hat die Raumaufteilung für die Zeugnisausgabe geschickt. Als EXCEL 3 Spalten, 35 Zeilen, warum?
Mäh W.2d ago
Unseen JapanJun 25

Not Japan-related, but since we all need a distraction from The Horrors, Takaya Suzuki points out a study that examined 408 sleeping cats and found the majority (65%) curl leftwards.

I'm not sure how useful this information is, but...it's yours now.

#japan #unseenjapan

Mäh W.3d ago
The_Sun4d ago

Ikea begins offering balcony solar kits

Swedish furniture retailer Ikea is selling plug-in solar kits in Germany, with storage-inclusive systems starting at €1,229 ($1,425) and reaching €2,800 for versions featuring four 520 W panels. The kits are designed for residential self-consumption and vary by capacity and configuration.
#ikea #Solar #energy #germany
https://www.pv-magazine.com/2025/06/25/ikea-begins-offering-balcony-solar-kits/

Ikea begins offering balcony solar kits

Swedish furniture retailer Ikea is selling plug-in solar kits in Germany, with storage-inclusive systems starting at €1,229 ($1,425) and reaching €2,800 for versions featuring four 520 W panels. The kits are designed for residential self-consumption and vary by capacity and configuration.

pv magazine International
Mäh W.3d ago
Atarius3d ago
Git es hier Rollenspieler*innen aus der Gegend von Donauwörth? #fedipower #pnpde #penandpaper #rollenspiel #Donauwörth
×
Show thread✧✦Catherine✦✧6d ago
we have SWD!
Show thread✧✦Catherine✦✧6d ago
the source code is not protected (i am reading out valid values), but for some reason my dump memory command is encountering errors; most likely a misunderstanding of ADIv5.2
Show thread✧✦Catherine✦✧6d ago

it looks like sometimes it works and sometimes it doesn't

very bold of a vendor to call it a "good device" when in fact it seems to be bad

Show thread✧✦Catherine✦✧6d ago
nevermind, it works fully once i attach a logic analyzer. for one reason or the other, adding a few pF of capacitance to the pins is what it needed
Show thread✧✦Catherine✦✧6d ago
here's a firmware name: WM_KT-EX9-10_2.12_GD103.bin
Show thread✧✦Catherine✦✧6d ago

did someone build the firmware with -funroll-loops or what

this is a part the code that copies static mutable data into RAM from Flash. it goes on for kilobytes

Show thread✧✦Catherine✦✧6d ago
there's actually a few loops in the middle doing the same memcopy operation. i think the compiler smokes crack
Show thread✧✦Catherine✦✧6d ago
although, a horrifying thought is that this is just what the original code looked like
Show thread✧✦Catherine✦✧6d ago

OH I GOT IT

i finally tracked down the source of this device, and also the gyroscope vendor

the WM_KT-EX9-10_2.12_GD103.bin in the firmware name most likely refers to the gyro:
https://en.ktjmyq.com/html/2024/MEMS_0526/141.html

KT-EX9-1 - MEMS GYROSCOPE - KaiTuo Precise Instrument Co., Ltd-accelerometer,Gyro,MEMS,MEMS Gyro,MEMS Accelerometer,KTJB1,KTFG,KTEX

FEATURESTriaxial, digital gyroscope, ±450° sec dynamic range ±0 05° orthogonal alignment error,0 3&

Show thread✧✦Catherine✦✧6d ago

i'm wrong. the KT-EX9-1 device has a public datasheet and some key values don't match

this could be a custom one-off or something?

Show threadSDRHoernchen6d ago
@whitequark.. Or just a shady copy of a copy, due to usage? Returns probably happen rarely, and the buyer might be a bit desperate.
Show thread✧✦Catherine✦✧6d ago
@SDRHoernchen it's possible, but I think it's somewhat unlikely
Show threadTimon 🛠5d ago
@whitequark One off'ish feels kinda likely. I seen that a few times in the med space despite doing that only briefly. Some sub-assembly was unobtainable so a shoddy "drop-in" that only replicates the features the specific device was using was made as it was easier/cheaper than redesigning the device itself.
Prob. not too different in the defense space?
Show thread✧✦Catherine✦✧5d ago
@timonsku yep, that's my guess; no reason to try and name the firmware to impersonate some other vendor
Show threadPhilip Guenther5d ago
@whitequark I’m fine with compilers NOT being responsible for all the final code sins of the world
Show threadTimon 🛠5d ago
@whitequark going full time freelance has truly opened my eyes when it comes to the state of software in the embedded space. I always assumed that I write mediocre code at best but the bar for "ready to ship" is in fact so much lower than I could have ever imagined
Show thread✧✦Catherine✦✧5d ago
@timonsku YEP.
Show threadMulti :companion_cube:6d ago
@whitequark mood
Show threadJoel Michael6d ago
@whitequark * Keil has entered the chat
Show threadAaron Sawdey, Ph.D.6d ago
@whitequark a frequent problem with compilers, actually. Sometimes it doesn’t even involve UB 😂
Show threadJoel Michael6d ago
@whitequark lolololol amazing, I guess they’re not using assembly for their init handler
Show thread✧✦Catherine✦✧6d ago
@jpm this firmware is weird
Show threadTóth Gábor Baltazár6d ago
@whitequark
that is indeed a fun roll :3
Show threadKevin Riggle6d ago
@whitequark putting the fun back in -funroll-loops
Show threadJaime6d ago
@whitequark I would definitely want my loops to be fun rolled, tbh
Show threadprom™️6d ago
@whitequark cat works fine when attached to logic analyzer. let me "make nconfig" for reasons. (it's been a day, not necessarily bad)
Show threadJ. "Henry" Waugh6d ago
@whitequark so you're saying that the analyzer knows when it's attached because it knows when it isn't? 😛
Show threadjaseg5d ago
@whitequark next version of Glasgow with DAC-controlled varactors on all pins for programmatic application of capacitive fiddle factors
Show thread✧✦Catherine✦✧5d ago
@jaseg i considered stuff like that
Show threadgaytabase6d ago
@whitequark i assume they are modelling it after 'good service' on public transport
Show threadJoel Michael6d ago
@whitequark oh wait, I vaguely recall that the GD32F103 fixed some silicon errata from the STM32F103 around debug handling.
Show thread✧✦Catherine✦✧6d ago
@jpm are you sure they haven't added any
Show threadJoel Michael6d ago

@whitequark no, my mistake, apparently it was the CKS clone STM32F103 that fixed ST’s silicon errata.

And yes, CKS added their own bugs: https://nvd.nist.gov/vuln/detail/CVE-2020-13464

NVD - CVE-2020-13464

Show threadpawlina🏳️‍⚧️🐾6d ago
@whitequark what exactly is that, what are you doing, i'm curious. looks very fancy awawa
Show thread✧✦Catherine✦✧6d ago

@alina the device on the image is a PCB i extracted from an inertial measurement unit from a loitering munition

you know that "the missile knows where it is because it knows where it isn't" meme? well, this PCB is _how_ the missile knows where it isn't

on the right i have a debugger connected to it, so that i can dump and analyze the firmware within and learn what makes it tick

Show threadpawlina🏳️‍⚧️🐾6d ago
@whitequark omg that's soo heckin cool :O
Show thread✧✦Catherine✦✧6d ago
@alina thank u ^^
Show threadF4GRX Sébastien5d ago
@whitequark aha, gold plated CLCC gyros?
Show thread✧✦Catherine✦✧5d ago
@f4grx the gyros apparently have vacuum inside of them (according to the vendor) which apparently makes them less sensitive to vibration!
Show thread✧✦Catherine✦✧5d ago
@f4grx I kinda want to open one up, I even have my trinocular here...
Show threadF4GRX Sébastien5d ago
@whitequark oh, did you try to make one run before teardown? They look quite nice. they're probably better than your average MPU6050.
Show thread✧✦Catherine✦✧5d ago

@f4grx it's still functioning, I have a script that makes it run

I could measure it properly, Allan deviation and the like, but purely from mouthfeel they don't feel like they're all that better. I don't have a good intuition though and I think numbers are the real way to tell

if you want me to collect some data and know to analyze it I can easily do that

Show threadF4GRX Sébastien5d ago

@whitequark no, it's quite complex and painful to characterize, there's a lot of noise measurements to be made, but these are statistical and I am unable to wrap my head around an actual meaning. it's just frustrating.

All I know is that when you use a gyro for dead reckoning, you integrate the rate over time twice and if the measurement has any bias, the integrated result will drift quadratically. Moreover, this "zero rate bias" varies with temperature and also if you look at the box sideways.

Show thread✧✦Catherine✦✧5d ago

@f4grx so, adis16488 is supposed to have an integrator for the angle

this box does not. it just reads as zeroes

i wonder if this means that it's not very good

Show threadF4GRX Sébastien5d ago
@whitequark looks like they did the vital minimum for the customer that wanted a cheaper adis16488. it just outputs the rates, and integration is made outside. probably the gd103 just translates spi protocols.
Show thread✧✦Catherine✦✧5d ago

@f4grx that is my conclusion as well

i have the gd103 firmware. i can share it but it's horrifying spaghetti

Show thread✧✦Catherine✦✧5d ago
@f4grx it would be mildly interesting to find out what the gyro protocol is. it's something low pin count as the flex cable just about has enough pins for SPI
Show threadF4GRX Sébastien5d ago
@whitequark can you post a relatively better res pic of one gyro? ideally one with a visible part number? :)
Show thread✧✦Catherine✦✧5d ago
@f4grx of course
Show threadF4GRX Sébastien5d ago

@whitequark startpage gave this with the 1001-011 search request https://geo-matching.com/products/high-performance-tactical-grade-mems-gyroscope

(I considered the second line a date code and the third line a lot code)

High Performance Tactical Grade MEMS Gyroscope

Features Proven and robust silicon MEMS gyro Up to ±400°/s measurement range 0.1°/hr bias instability 0.05°/√hr angular random walk Digital output (SPI slave) 5V operation (4.75~5.25V supply) Low power consumption (35 mA) High shock and vibration rej...

Show thread✧✦Catherine✦✧5d ago

@f4grx huh, what was the query?

also, wtf is that website? ubo lite doesn't let me follow any links that lead to "syndicatedsearch.goog"

Show threadF4GRX Sébastien5d ago

@whitequark Now I get more good looking stuff, I swear I did not get that before.

example: https://avictech.en.made-in-china.com/product/FOStsiZvGITD/China-High-Measure-Range-Single-Axis-Mems-Gyro-Chips-for-Automatic-Driving.html

Show threadF4GRX Sébastien5d ago
@whitequark ah here is the query I made previously.
Show threadF4GRX Sébastien5d ago

@whitequark avictech new ref https://avictech.en.made-in-china.com/product/sAJUXYnyglhq/China-Inertial-Navigation-System-High-Performance-North-Seeking-Mems-Gyroscope-MGZ330HC-A1.html

Is this a classic package for gyros or the same product renamed?

[Hot Item] Inertial Navigation System High Performance North Seeking Mems Gyroscope MGZ330HC-A1

Model NO.: MGZ330HC-A1 Type: Servo Output Signal Type: Digital Output Measuring Shaft Quantities: Single Accuracy Grade: 0.02deg IP Rating: IP67

Made-in-China.com
Show threadF4GRX Sébastien5d ago
@whitequark Also, what about this little dude? if the golden ones are 1 axis acceleros (so there are 3) then this little one should be the 3-axis gyro.
Show threadHenning Paul DC4HP5d ago
@f4grx @whitequark Well, well, well, what do we have here? https://szmlwndz.en.made-in-china.com/product/CTyUdGbVLKWz/China-High-Precision-3-Axis-Imu-Gyroscope-and-Accelerometer-for-Navigation-and-Motion-Sensing-Adis16488-Replacement.html
[Hot Item] High-Precision 3-Axis Imu Gyroscope and Accelerometer for Navigation and Motion Sensing - Adis16488 Replacement

Type: Gyroscope Data Transmission Interfaces: RS232/ RS422/RS485/Ttl/Can Interface: Spi Weight: 40g Voltage: 3.3 Vibration: 6.06g (20-2000Hz)

Made-in-China.com