Hyundai Paywalls Brake Pad Changes

Changing the pads on your car’s brakes is a pretty straightforward and inexpensive process on most vehicles. However, many modern vehicles having electronic parking brakes giving manufacturers a new avenue to paywall simple DIY repairs.

Most EVs will rarely, if ever, need to replace their mechanical brake pads as in most driving situations the car will be predominantly relying on regenerative braking to slow down. A hot hatch like the Ioniq 5N, however, might go through brakes a lot faster if it spends a lot of time at the track, which is what happened with Reddit user [SoultronicPear].

Much to their chagrin, despite buying the required $60/wk subscription to the National Automotive Service Task Force (NASTF) and the $2,000 interface tool, [SoultronicPear]’s account was suspended because it was not intended for use for anyone but “service professionals.” Not exactly a Right-to-Repair friendly move on Hyundai’s part. After trying a number of different third party tools, they finally found a Harbor Freight T7 bidirectional scan tool was able to issue the parking brake retract command to perform the pad swap, albeit not without throwing some error codes in the process.

Electrification of vehicles should simplify repairs, but manufacturers are using it to do the opposite. Perhaps they should read our Minimal Motoring Manifesto? There is a glimmer of hope in the promises of Slate and Telo, but we’ll have to see if they make it to production first.

hackaday.com/2025/11/15/hyunda…

(Neural) Networking with a Business Card

A PCB business card is a great way for electrical engineers to impress employers with their design skills, but the software they run can be just as impressive as the card itself. As a programmer with an interest in embedded machine learning, [Dave McKinnon] wanted a card that showcased his skills, so he designed one that runs voice recognition.

[Dave] specifically wanted to run a neural network on his card, but needed to make it small enough to run on a microcontroller. Voice recognition looked like a good fit for this, since audio can be represented with relatively little data, a microphone is cheap and easy to add to a circuit board, and there was already an example of someone running such a voice recognition network on an Arduino. To fit the neural network into 46 kB, it only distinguishes the words “one” through “nine,” and displays its guess on an LED seven-segment display. [Dave] first prototyped the system with an Arduino, then designed the circuit board around an RP2040.

The switch from Arduino to the RP2040 brought with it a mysterious change: it would usually recognize the word “eight,” but none of the other numbers. After much investigation, it turned out that the new circuit was presenting samples at a much higher rate than the older one had, which was throwing the network off. [Dave] increased the sampling period and had the user speak the numbers slowly, which solved the issue.

The microcontroller was well chosen; the RP2040 is good enough for machine learning that there are dev boards explicitly designed for it, and even comparatively less powerful Arduino boards can do surprisingly good voice recognition. On the hardware side, [Dave] cited some of the Linux business cards we’ve seen as inspiration.

hackaday.com/2025/11/15/neural…

Using the Pyroelectric Effect to Identify Broken MLCC Capacitors

Vintage computer hardware can fail in a variety of fascinating ways, with [Bits und Bolts] dealing with an interesting failure mode, in the form of degraded MLCC capacitors on Voodoo 2 graphics cards. These little marvels of miniaturized surface-mount technology enable the placement of ceramic capacitors with very little space required, but as they degrade over time or due to physical damage, they can cause big issues in a circuit.

In the case of the two Voodoo 2 GPUs that [Bits und Bolts] was trying to fix, the clue that something was wrong was graphical glitches, which seemed to be related to something dragging down the 5V rail. Using the standard ‘inject voltage and see what gets hot’ method, he discovered a couple of dead MLCCs and replaced them. But something was still dragging the rail down. Unfortunately, whatever it was wasn’t enough to heat up the part in question, and no sane person wants to desolder hundreds or even thousands of MLCCs on a PCB and see whether it makes a difference.

Ultimately, the pyroelectric effect was used to hunt down the culprit, saving countless hours of work. This is a property of certain naturally electrically polarized crystals, in which the material generates a voltage when heated or cooled. Materials like that used in MLCCs, for example.

With a hot air gun set to 200 °C and aimed at a specific MLCC, it was possible to measure changes not only in resistivity but also in voltage between the 5V rail and ground. The voltage spike was relatively minor for the smaller MLCCs, but the larger ones showed a significant voltage swing of around 2.5mV.

The culprit turned out to be a large MLCC, which showed only a weak pyroelectric effect and a resistivity that didn’t drop as quickly as that of similar MLCCs on the same board. After replacement, the faulty MLCC did indeed measure as faulty, and the card’s 5V rail now showed a healthy resistance level to ground.

In addition to knowing what kind of resistivity you should measure on a PCB’s voltage rails relative to ground, this method provides a fairly painless way to quickly find a dodgy MLCC. Just make sure not to try this method on electrolytic or tantalum. Heating those up won’t go well.

We often treat decoupling capacitors as more art than science, but of course, we shouldn’t. MLCCs can even exhibit the piezoelectric effect, too.

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hackaday.com/2025/11/15/using-…

The Engineering Behind Valve’s new VR Headset

Valve’s new Steam Frame is what all the well-connected YouTubers are talking about, but most of them are talking about what it’s like to game on it. That’s great content if you’re into it, but not exactly fodder for Hackaday — with one exception. [Gamers Nexus] gives us a half hour of relatively-unedited footage of them just chatting with the engineers behind the hardware.

It’s great stuff right from the get-go: they start with how thermal management drove the PCB design, and put the SoC on the “back” of the chip, sandwiched betwixt heat pipes. We don’t usually think of taking heat through the PCB when building a board, so it’s a neat detail to learn about before these things get into the hands of the usual suspects who will doubtless give us teardown videos in a few months.

From there wanders to power delivery — getting the voltage regulators packaged properly was a challenge, since impedance requirements meant a very tight layout. Anyone who has worked on this kind of SBC might be familiar with that issue, but for those looking in from the outside, it’s a fascinating glimpse at electrical sausage being made. That’s just the first half.

The heat-regulation conversation is partially repeated the next conversation (which seems to have happened first) where they get into the cooling requirements of the LCD screens. This requires less than you might think, as they like to run warm for fast refresh. It’s really more about keeping your face cool. They also they discuss acoustic vibration — you don’t want your integrated audio shaking your IMUs apart — and why the prototype was being blasted with freakin’ laser beams to monitor it.

If you haven’t seen or read any other coverage on the Steam Frame, you’re going to miss some context here, but if you’ve not hid under a rock for that announcement, this is amazing detail to have. We’re hugely impressed that Valve let their engineers out of their cubicle-cave to talk to media.

Sure, it’s not an open-source VR headset, but compared to the deafening silence coming from the likes of Meta, this level of information is still awesome to have.

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hackaday.com/2025/11/15/the-en…

The Value of a Worked Example

I was looking over the week’s posts on Hackaday – it’s part of my job after all – and this gem caught my eye: a post about how to make your own RP2040 development board from scratch. And I’ll admit that my first thought was “why would you ever want to do that?” (Not a very Hackaday-appropriate question, honestly.) The end result will certainly cost more than just buying a Pi Pico off the shelf!

Then it hit me: this isn’t a project per se, but rather [Kai] was using it as an test run to learn the PCB-production toolchain. And for that, replicating a Pico board is perfect, because the schematics are easily available. While I definitely think that a project like this is a bit complicated for a first PCB project – I’d recommend making something fun like an SAO – the advantage of making something slightly more involved is that you run into all of the accompanying problems learning experiences. What a marvelous post-complete-beginner finger exercise!

And then it hit me again. [Kai]’s documentation of everything learned during the project was absolutely brilliant. It’s part KiCAD tutorial, part journal about all the hurdles of getting a PCB made, and just chock-full of helpful tips along the way. The quality of the write-up turns it from being just a personal project into something that can help other people who are in exactly the same boat, and I’m guessing that’s a number of you out there.

In the end, this was a perfect Hackaday project. Yes, it was “too simple” for those who have made their 30th PCB design. (Although I’d bet you could still pick up a KiCAD tip or two.) And yes, it doesn’t make economic sense to replicate mass-market devices in one-off. And of course, it doesn’t need that fun art on the board either. But wrap all these up together, and you get a superbly documented guide to a useful project that would walk you through 95% of what you’ll need to make more elaborate projects later on. Superb!

Surely you do “finger exercises” too. Why not write them up, and share the learning? And send them our way – we know just the audience who will want to read it.

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