Noname LED bike helmet autopsy (WHL #81)

Chinese junk that appeared on my work bench this week!

Well – it’s a bike helmet. An LED bike helmet. A colleague brought it over and asked if I could install an USB type-C port since he (or his wife?) brutally murdered the micro USB in the back. Sure, pinouts are basically identical and access to the thing is darn easy. Oh, no, they’re not.

Turns out this thing can be tossed, since he doesn’t want her to use a nonfunctional LED helmet that furthermore still has a ticking lithium time bomb in it. So I did, after extracting all the goodness shown below. […]


The WHL Director of Human Resources (#R17)

We at Wan Hung Lo Enterprises have grown considerably over the years. Our new director of HR (so high up he doesn’t even need a name) now sends out strange mails to the peasants that also don’t have a name, not even a number…

Wait a minute, it’s still me running the whole show, TF is that?

Well, looks like Titan Technology (the cooler and fan specialists that were pretty popular fifteen years ago – still in business!) might have lost a bit of their customer database. I think I enquired a long time ago for a datasheet and needed to provide an email address for that; it’s not the one shown below, this mail was received by the catchall option that typically categorizes those mails as spam right away. […]


MariaDB/SQL query gotcha and optimized solution (#E18)

Haven’t had a general advice post for a while, have we.

My small fleet of ESP32 boards across the apartment is still gathering information for the AVM Fritz DECT 301 radiator control units that just started the heating season. While their queries are really simple, quick and fully automated, I also have an HighCharts overview plot of all data with user-defined query depth, usually 300 minutes / 5 hours, but I think there’s no arbitrary limit to it. One could plot all 2 million rows of data…but I’m not gonna try.

Anyway, I recently noticed query times went up significantly, and the whole thing never was blazing fast in the first place. […]


o2 DSL Router Premium disassembly/yellowing surprise (WHL #80)

I don’t often visit family, but when I do, my car is usually filled to the roof with old tech crap when I come back…and so is the apartment over the next couple of weeks, until everything is checked, repaired (if needed/viable) and subsequently stored, gifted, sold or binned.

Well, there’s this old o2 router (different labelling, I know…) back from the era where

a) internet providers were able to force you using their crappy loaner hardware (I did hack a similar unit back in the days, te-he-he),
b) those devices sometimes contained a WiFi module that was disabled by default but could be unlocked for a couple bucks per month (I never got why people do this over 24+ months instead of just buying a standalone AP), and
c) not sending back those miracles of NATted IPv4 tech at the end of your contract could easily cost you north of 100€, a ridiculous money-making scheme that was only stopped years later by court decisions that got delayed and appealed forever. […]


Leoch DJW12-5.0(F2 12V5.0Ah) Maintenance-free Sealed Lead-acid Battery cohort testing and refilling (WHL #79)

Batteries. Plain old lead-acid batteries for today.

Before I left to Scotland, IT dropped a bunch of UPS batteries in my office. And since I wasn’t present, they asked my colleague to get them tested, you know, just sort out the bad ones. Sure thing.

It’s 119 of them, plus two dozen more of a larger size (9Ah) that are more common in those desktop APC units that I also use at home. All in all over 200kg of lead. Well, thanks a lot…

Thing is: I don’t have time for that. And it’s not my job. And with the limited equipment I have at hand (at work…), it took me well over a month to get them all tested alongside regular work. […]


The 2022 Royal Edinburgh Military Tattoo and another useless FLIR video (#R16)

Do I rant too much? I probably do.

Is it unfounded? Probably not.

So, I’ve done a slightly insane yet enjoyable trip to Scotland and covered 2000 miles in 8.5 days, thanks to the wonders of free lifetime supercharging on my Tesla. End point of the trip was the Royal Edinburgh Military Tattoo show on 25th of September, for which getting a single ticket on the desired “7” block was a bit tricky, but worked out in the end. And while literally hundreds of the crowd of around 9000 people had their phones up quite a lot of the time (does anyone watch those hour long videos of wobbly footage?), […]


Dremel 575 Right Angle Attachment (WHL #78)

I recently got a Dremel 575 90° adapter for tackling a problem that would have been much easier to solve in 4D space – and I returned it the next day for a new unit. It was running pretty rough due to the input shaft actually wobbling around by a millimeter, but even with that fixed in the second unit, it still has a very harsh, grinding, mechanical sound to it. I do not dare to run this at full speed of my 35krpm Dremel 4000, although the one-page manual does not specify any restrictions.

(I know, colors are off, I twiddled with the camera settings on my recent vacation…that made me miss a blog post on top of that!) […]


DC DC Step Down Power Module 5-16V To 1.25V/1.5V/1.8V/2.5V/3.3V/5V Universal Adjustable Buck Voltage Converter Board 3A For LCD (WHL #77)

Just a brief service tweet announcement for today, no in-depth review of the thing – these super helpful, small and cheap “CA-1235” DC-DC buck converters, commonly available for 50 cents a pop (plus postage), do use a Monolithic Power MP1495 TSOT-23-8 control chip labelled “IACSE” – or a clone thereof. While that connection is not immediately obvious and not mentioned by MPS (it says chip labelling “ACS”), teh Googles knows about this and leads to a suitable datasheet. Some variants of the chip itself are not recommended for new designs, but of course there’s still a lot of stock and probably clones available out there, even Mouser lists a couple of original parts with hundreds of units available. […]


L40 Mixed Color Cube Various size For Home Or Office Toy Science Learning Cube Easter Prism Desktop Toy Home Ornament (WHL #76)

Electronics-free interlude for today.

That shameless advertising video from Vsauce

kickstarted my interest in those color-mixing (well, subtracting) “CMY” cubes.

A quick check of their website reveals their equally shameless pricing of 20/30/70 USD for 30/50/95mm cubes, ten bucks on top for international shipping, and, outside of their control, the local government slaps on another shameless 19% of VAT. Well, that’s 36, 48 or 95 USD=EUR for a novelty gadget. 1.32/0.38/0.11 € per cubic centimeter, to be precise. OK, cool but a bit steep. […]


The bk Group supercharger lounge revisited (#R15F1)

Well, told ya I’ll be visiting the strange bk world supercharger lounge again. I actually did a month ago, but here we are.
So, the good news first: It’s actually working now. It did require re-registration, but after a couple of minutes of fiddling on the smartphone, I finally got a barcode that unlocked the doors! Let’s just hope this isn’t required ever again, e.g. due to killing inactive accounts or a system migration…

The outside of those two wooden cubes was already featured in the original post #R15, so let’s start inside. […]