The Lowly Wall Wart Laid Bare

Getting a look at the internals of a garden variety “wall wart” isn’t the sort of thing that’s likely to excite the average Hackaday reader. You’ve probably cracked one open yourself, and even if you haven’t, you’ve likely got a pretty good idea of what’s inside that sealed up brick of plastic. But sometimes a teardown can be just as much about the journey as it is the end result.

Truth be told, we’re not 100% sure if this teardown from [Brian Dipert] over at EDN was meant as an April Fool’s joke or not. Certainly it was posted on the right day, but the style is close enough to some of his previous work that it’s hard to say. In any event, he’s created a visual feast — never in history has an AC/DC adapter been photographed so completely and tastefully.

An Ode to the Diode

[Brian] even goes so far as to include images of the 2.5 lb sledgehammer and paint scraper that he uses to brutally break open the ultrasonic-welded enclosure. The dichotomy between the thoughtful imagery and the savage way [Brian] breaks the device open only adds to the surreal nature of the piece. Truly, the whole thing seems like it should be part of some avant garde installation in SoHo.

After he’s presented more than 20 images of the exterior of the broken wall wart, [Brian] finally gets to looking at the internals. There’s really not much to look at, there’s a few circuit diagrams and an explanation of the theory behind these unregulated power supplies, and then the write-up comes to a close as abruptly as it started.

So does it raise the simple teardown to an art form? We’re not sure, but we know that we’ll never look at a power adapter in quite the same way again.

A Toothbrush Hacked, In Three Parts

It’s official, we’re living in the future. Certainly that’s the only explanation for how [wrongbaud] was able to write a three-part series of posts on hacking a cheap electric toothbrush off of AliExpress.

As you might have guessed, this isn’t exactly a hack out of necessity. With a flair for explaining hardware hacking, [wrongbaud] has put this together as a practical “brush-up” (get it?) on the tools and concepts involved in reverse engineering. In this case, the Raspberry Pi is used as a sort of hardware hacking multi-tool, which should make it relatively easy to follow along.

Modified image data on the SPI flash chip.

The first post in the series goes over getting the Pi up and running, which includes setting up OpenOCD. From there, [wrongbaud] actually cracks the toothbrush open and starts identifying interesting components, which pretty quickly leads to the discovery of a debug serial port. The next step is harassing the SPI flash chip on the board to extract its contents. As the toothbrush has a high-res color display (of course it does), it turns out this chip holds the images which indicate the various modes of operation. He’s eventually able to determine how the images are stored, inject new graphics data, and write it back to the chip.

Being able to display the Wrencher logo on our toothbrush would already be a win in our book, but [wrongbaud] isn’t done yet. For the last series in the post, he shows how to extract the actual firmware from the microcontroller using OpenOCD. This includes how to analyze the image, modify it, and eventually flash the new version back to the hardware — using that debug port discovered earlier to confirm the patched code is running as expected.

If you like his work with a toothbrush, you’ll love seeing what [wrongbaud] can do with an SSD or even an Xbox controller.

Why The LM741 Sucks

First of all, we’d like to give a big shout-out to [Afrotechmods]! After a long hiatus, he has returned to YouTube with an awesome new video all about op-amp characteristics, looking at the relatively awful LM741 in particular. His particular way of explaining things has definitely helped many electronics newbies to learn new concepts quickly!

Operational amplifiers have been around for a long time. The uA741, now commonly known as the LM741, was indeed an incredible piece of technology when it was released. It was extremely popular through the 1970s and onward as it saved designers the chore of designing a discrete amplifier. Simply add a few external components, and you have a well-behaved amplifier.

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An Elegant Writer For A More Civilized Age

One of the most exciting trends we’ve seen over the last few years is the rise of truly personal computers — that is, bespoke computing devices that are built by individuals to fit their specific needs or wants. The more outlandish of these builds, often inspired by science fiction and sporting non-traditional layouts, tend to be lumped together under the term “cyberdecks”, but there are certainly builds where that description doesn’t quite stick, including the Cyber Writer from [Darbin Orvar].

With a 10-inch screen, you might think it was intended to be a portable, but its laser-cut Baltic birch plywood construction says otherwise. Its overall design reminds us of early computer terminals, and the 60% mechanical keyboard should help reinforce that feeling that you’re working on a substantial piece of gear from yesteryear.

There’s plenty of room inside for additional hardware.

The Cyber Writer is powered by the Raspberry Pi Zero W 2, which might seem a bit underpowered, but [Darbin] has paired it with a custom minimalist word processor. There’s not a lot of detail about the software, but the page for the project says it features integrated file management and easy email export of documents.

The software isn’t yet available to the public, but it sounds like [Darbin] is at least considering it. Granted, there’s already distraction-free writing software out there, but we’re pretty firm believers that there’s no such thing as too many choices.

If you’re looking for something a bit more portable, the impressive Foliodeck might be more your speed.

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A Forgotten Photographic Process Characterised

Early photography lacked the convenience of the stable roll film we all know, and instead relied on a set of processes which the photographer would have to master from film to final print. Photographic chemicals could be flammable or even deadly, and results took a huge amount of work.

The daguerreotype process of using mercury to develop pictures on polished metal, and the wet-collodion plate with its nitrocellulose solution are well-known, but as conservators at the British National Archives found out, there was another process that’s much rarer. The Pannotype uses a collodion emulsion, but instead of the glass plate used by the wet-plate process it uses a fabric backing.

We know so much about the other processes because they were subject to patents, but pannotype never had a patent due to a disagreement. Thus when the conservators encountered some pannotypes in varying states of preservation, they needed to apply modern analytical techniques to understand the chemistry and select the best methods of stabilization. The linked article details those analyses, and provides them with some pointers towards conserving their collection. We look forward to someone making pannotype prints here in 2025, after all it’s not the first recreation of early photography we’ve seen.

Malfunctional Timekeeping With The Vetinari Clock

Lord Vetinari from the Discworld series is known for many things, but perhaps most of all a clock that doesn’t quite keep continuous time. Instead, it ticks away at random increments to infuriate those that perceive it, whilst keeping regular time over the long term. [iracigt] decided to whip up a real world version of this hilarious fictional timepiece.

The clock itself is an off-the-shelf timepiece purchased from Target for the princely sum of $5. However, it’s been deviously modified with an RP2040 microcontroller hidden away inside. The RP2040 is programmed to tick the clock at an average of once per second. But each tick itself is not so exact. Instead, there’s an erraticness to its beat – some ticks are longer, some shorter, in the classic Vetinari style. [iracigt] explains the nitty gritty of how it all works, from creating chaos with Markov chains to interfacing the RP2040 electronically with the cheap quartz clock movement.

If you’ve ever wanted to build one of these amusements yourself, [iracigt’s] writeup is a great place to start. Even better, it was inspired by an earlier post on these very pages! We love to see the community riff on a theme, and we’d love to see yours, too – so keep the tips coming, yeah? Video after the break.

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Shrinking Blinky As Far As Possible

Many of us know the basic Blink Arduino sketch, or have coded similar routines on other microcontrollers. Flashing an LED on and off—it doesn’t get much simpler than that. But how big should a blink sketch be? Or more importantly, how small could you get it? [Artful Bytes] decided to find out.

The specific challenge? “Write a program that runs on a microcontroller and blinks an LED. The ON and OFF times should be as close to 1000 ms as possible.” The challenge was undertaken using a NUCLEO-L432KC Cortex-M4 with 256 K of flash and 64 K of RAM.

We won’t spoil the full challenge, but it starts out with an incredibly inefficient AI & cloud solution. [Artful Bytes] then simplifies by switching to an RTOS approach, before slimming down further with C, assembly, and then machine code. The challenge was to shrink the microcontroller code as much as possible. However, you might notice the title of the video is “I Shrunk Blinky to 0 Bytes.” As it turns out, if you eliminate the digital code-running hardware entirely… you can still blink an LED with analog hardware. So, yes. 0 bytes is possible.

We’ve featured the world’s smallest blinky before, too, but in a physical sense rather than with regards to code size.

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