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   ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 04:33:21 JST ✧✦Catherine✦✧

   the delta-angle and delta-velocity functionality appears to simply not exist, which excludes this being a faithful clone of either adis16488 or adis16375

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 05:09:17 JST ✧✦Catherine✦✧

     in reply to

     oh, i just realized that it has a "product ID" register that clearly says 0x4068 (16488). so it's supposed to be a clone of ADIS16488 then. it's just a very bad one

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 05:17:03 JST ✧✦Catherine✦✧

     in reply to

     • Rev. Poppy Haze 𓅋

     this thing doesn't seem to have a magnetometer or a barometer, it's just an accelerometer and a gyroscope. not even very good ones, they're probably on par with what your cellphone has, if not worse

     i think some enterprising company (possibly Shenznen Firepower Control Co. Ltd. based on @poppyhaze's research) has realized they can make a lot of money selling ADIS16488-style devices that only barely work at a half of their sticker price from AD

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     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 05:34:16 JST ✧✦Catherine✦✧

     in reply to

     • Rev. Poppy Haze 𓅋
     • Henning Paul DC4HP

     @hennichodernich @poppyhaze that's a rather... optimistic way to describe it

   • Embed this notice
     Henning Paul DC4HP (hennichodernich@radiosocial.de)'s status on Monday, 30-Jun-2025 05:34:17 JST Henning Paul DC4HP

     in reply to

     • Rev. Poppy Haze 𓅋

     @whitequark @poppyhaze So something we call a second source... 😬

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 06:40:43 JST ✧✦Catherine✦✧

     in reply to

     oh... it has a GD32F103 inside. there are even, conveniently, pads with SWD routed to them

     firmware dumping time? firmware dumping time.

   • Embed this notice
     Joel 🔪 May-Kill 🔪 (jpm@aus.social)'s status on Monday, 30-Jun-2025 07:02:04 JST Joel 🔪 May-Kill 🔪

     in reply to

     @whitequark that explains the SPI controller weirdness…

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 07:02:04 JST ✧✦Catherine✦✧

     in reply to

     • Joel 🔪 May-Kill 🔪

     @jpm :)

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 07:09:17 JST ✧✦Catherine✦✧

     in reply to

     we have SWD!

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 07:24:59 JST ✧✦Catherine✦✧

     in reply to

     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

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     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 07:36:19 JST ✧✦Catherine✦✧

     in reply to

     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

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 07:36:52 JST ✧✦Catherine✦✧

     in reply to

     • Joel 🔪 May-Kill 🔪

     @jpm are you sure they haven't added any

   • Embed this notice
     Joel 🔪 May-Kill 🔪 (jpm@aus.social)'s status on Monday, 30-Jun-2025 07:36:53 JST Joel 🔪 May-Kill 🔪

     in reply to

     @whitequark oh wait, I vaguely recall that the GD32F103 fixed some silicon errata from the STM32F103 around debug handling.

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 07:52:49 JST ✧✦Catherine✦✧

     in reply to

     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

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 07:56:31 JST ✧✦Catherine✦✧

     in reply to

     here's a firmware name: WM_KT-EX9-10_2.12_GD103.bin

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 08:07:52 JST ✧✦Catherine✦✧

     in reply to

     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

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 08:11:54 JST ✧✦Catherine✦✧

     in reply to

     there's actually a few loops in the middle doing the same memcopy operation. i think the compiler smokes crack

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 08:17:10 JST ✧✦Catherine✦✧

     in reply to

     although, a horrifying thought is that this is just what the original code looked like

   • Embed this notice
     Joel 🔪 May-Kill 🔪 (jpm@aus.social)'s status on Monday, 30-Jun-2025 08:17:36 JST Joel 🔪 May-Kill 🔪

     in reply to

     @whitequark lolololol amazing, I guess they’re not using assembly for their init handler

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     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 08:17:36 JST ✧✦Catherine✦✧

     in reply to

     • Joel 🔪 May-Kill 🔪

     @jpm this firmware is weird

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 08:19:12 JST ✧✦Catherine✦✧

     in reply to

     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

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 08:41:31 JST ✧✦Catherine✦✧

     in reply to

     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?

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 10:12:30 JST ✧✦Catherine✦✧

     in reply to

     • SDRHoernchen

     @SDRHoernchen it's possible, but I think it's somewhat unlikely

   • Embed this notice
     SDRHoernchen (sdrhoernchen@chaos.social)'s status on Monday, 30-Jun-2025 10:12:32 JST SDRHoernchen

     in reply to

     @whitequark.. Or just a shady copy of a copy, due to usage? Returns probably happen rarely, and the buyer might be a bit desperate.

   • Embed this notice
     Jaime (phofe@mastodon.social)'s status on Monday, 30-Jun-2025 15:19:53 JST Jaime

     in reply to

     @whitequark I would definitely want my loops to be fun rolled, tbh

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 19:57:31 JST ✧✦Catherine✦✧

     in reply to

     • jaseg

     @jaseg i considered stuff like that

   • Embed this notice
     jaseg (jaseg@chaos.social)'s status on Monday, 30-Jun-2025 19:57:32 JST jaseg

     in reply to

     @whitequark next version of Glasgow with DAC-controlled varactors on all pins for programmatic application of capacitive fiddle factors

   • Embed this notice
     Timon 🛠 (timonsku@mastodon.social)'s status on Monday, 30-Jun-2025 20:43:03 JST Timon 🛠

     in reply to

     @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

   • Embed this notice
     Timon 🛠 (timonsku@mastodon.social)'s status on Monday, 30-Jun-2025 20:50:15 JST Timon 🛠

     in reply to

     @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?

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 20:50:23 JST ✧✦Catherine✦✧

     in reply to

     • Timon 🛠

     @timonsku YEP.

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 20:51:07 JST ✧✦Catherine✦✧

     in reply to

     • Timon 🛠

     @timonsku yep, that's my guess; no reason to try and name the firmware to impersonate some other vendor

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 21:53:46 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien
     • Rev. Poppy Haze 𓅋

     @f4grx @poppyhaze the alibaba vendors sell these for somewhere between $650-$1000, though the question is open how much the customized unit i'm looking at has been going for; i'm sure there's a negotiated agreement in place

   • Embed this notice
     F4GRX Sébastien (f4grx@chaos.social)'s status on Monday, 30-Jun-2025 21:53:47 JST F4GRX Sébastien

     in reply to

     • Rev. Poppy Haze 𓅋

     @whitequark @poppyhaze holy crap just had a look a mouser and yikes. tactical grade price indeed.

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 21:55:39 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @f4grx the gyros apparently have vacuum inside of them (according to the vendor) which apparently makes them less sensitive to vibration!

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 21:55:39 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @f4grx I kinda want to open one up, I even have my trinocular here...

   • Embed this notice
     F4GRX Sébastien (f4grx@chaos.social)'s status on Monday, 30-Jun-2025 21:55:41 JST F4GRX Sébastien

     in reply to

     @whitequark aha, gold plated CLCC gyros?

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 21:59:22 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @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

   • Embed this notice
     F4GRX Sébastien (f4grx@chaos.social)'s status on Monday, 30-Jun-2025 21:59:23 JST F4GRX Sébastien

     in reply to

     @whitequark oh, did you try to make one run before teardown? They look quite nice. they're probably better than your average MPU6050.

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 22:06:29 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @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

   • Embed this notice
     F4GRX Sébastien (f4grx@chaos.social)'s status on Monday, 30-Jun-2025 22:06:30 JST F4GRX Sébastien

     in reply to

     @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.

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 22:10:37 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @f4grx that is my conclusion as well

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

   • Embed this notice
     F4GRX Sébastien (f4grx@chaos.social)'s status on Monday, 30-Jun-2025 22:10:38 JST F4GRX Sébastien

     in reply to

     @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.

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 22:12:28 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @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

   • Embed this notice
     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 22:21:09 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @f4grx of course

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     F4GRX Sébastien (f4grx@chaos.social)'s status on Monday, 30-Jun-2025 22:21:10 JST F4GRX Sébastien

     in reply to

     @whitequark can you post a relatively better res pic of one gyro? ideally one with a visible part number? :)

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     ✧✦Catherine✦✧ (whitequark@mastodon.social)'s status on Monday, 30-Jun-2025 23:28:13 JST ✧✦Catherine✦✧

     in reply to

     • F4GRX Sébastien

     @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"

   • Embed this notice
     F4GRX Sébastien (f4grx@chaos.social)'s status on Monday, 30-Jun-2025 23:28:14 JST F4GRX Sébastien

     in reply to

     @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)