PNG Image Decoding Library Does It With Minimal RAM

Want to display a PNG file on a display attached to an Arduino or other microcontroller board? You’ll want to look at [Larry Bank]’s PNGdec, the Arduino-friendly PNG decoder library which makes it much easier to work with PNG files on your chosen microcontroller.

The PNG image format supports useful features like lossless compression, and was generally developed as an improved (and non-patented) alternative to GIF files. So far so great, but it turns out that decoding PNG files on a microcontroller is a challenge due to the limited amount of memory compared to desktop machines. When the PNG specification was developed in the 90s, computers easily had megabytes of memory to work with, but microcontrollers tend to have memory measured in kilobytes, and lack high-level memory management. [Larry]’s library addresses these issues.

PNGdec is self-contained and free from external dependencies, and also has some features to make converting pixel formats for different display types easy. It will run on any microcontroller that can spare at least 48 K of RAM, so if that sounds useful then check out the GitHub repository for code and examples.

We’ve seen [Larry]’s wonderful work before on optimizing GIF playback as well as rapid JPEG decoding, and these libraries have increasing relevance as hobbyists continue to see small LCD and OLED-based displays become ever more accessible and affordable.

[PNG logo: PNG Home Site]

Teardown: VTech Smart Start

Regular readers may be aware that I have a certain affinity for vintage VTech educational toys, especially ones that attempted to visually or even functionally tie in with contemporary computer design. In the late 1980s, when it became obvious the personal computer was here to stay, these devices were seen as an affordable way to give kids and even young teens hands-on time with something that at least somewhat resembled the far more expensive machines their parents were using.

Much Smarter: VTech PreComputer 1000

A perfect example is the PreComputer 1000, released in 1988. Featuring a full QWERTY keyboard and the ability to run BASIC programs, it truly blurred the line between toy and computer. In fact from a technical standpoint it wasn’t far removed from early desktop computers, as it was powered by the same Zilog Z80 CPU found in the TRS-80 Model I.

By comparison, the Smart Start has more in common with a desktop electronic calculator. Even though it was released just two years prior to the PreComputer 1000, you can tell at a glance that it’s a far more simplistic device. That’s due at least in part to the fact that it was aimed at a younger audience, but surely the rapid advancement of computer technology at the time also played a part. Somewhat ironically, VTech did still at least attempt to make the Smart Start look like a desktop computer, complete with the faux disk drive on the front panel.

Of course, looks can be deceiving. While the Smart Start looks decidedly juvenile on the outside, that doesn’t mean there aren’t a few surprising technical discoveries lurking under its beige plastic exterior. There’s only one way to find out.

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Motorized Camera Slider Gives Your Shots Style

We’ve all seen those smooth panning shots, which combined with some public domain beats, are a hallmark of the modern YouTube tech video. Recreating that style in your own productions is as easy as pointing your browser to Amazon and picking up a motorized camera slider, so long as you don’t mind parting with a few hundred bucks, anyway. But [Paweł Spychalski] had a better idea. He decided to build his own camera slider and make it an open source project so others could spin up their own versions.

His design uses many components that have become popular and affordable thanks to the desktop 3D printer explosion, such as 2020 aluminum extrusion, LM8UU linear bearings, an 8 mm lead screw, and a NEMA 17 stepper motor. In fact, if you’ve got a broken 3D printer that you don’t know what to do with, stripping it for parts would get you a long way towards completing the BOM for this project.

To control the slider, [Paweł] is using an ESP32 and TMC2209 “StepStick” driver connected to an OLED display and a few buttons. As designed, a smartphone connected to a simple web page hosted by the ESP32 is the primary method of controlling the camera, but the buttons and display on the slider itself gives you a physical backup should you need it.

If you need something a bit more advanced than a linear slider, we’ve seen some impressive DIY motion rigs that can spin the camera around the target and produce some very professional looking shots.

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Did You Meet Pepper?

Earlier this week it was widely reported that Softbank’s friendly-faced almost-humanoid Pepper robot was not long for this world, as the Japanese company’s subsidiary in France that had been responsible for the robotic darling of the last decade was being downsized, and that production had paused. Had it gone the way of Sony’s Aibo robotic puppy or Honda’s crouching-astronaut ASIMO? It seems not, because the company soon rolled back a little and was at pains to communicate that reports of Pepper’s untimely death had been greatly exaggerated. It wasn’t so long ago that Pepper was the face of future home robotics, so has the golden future become a little tarnished? Perhaps it’s time to revisit our plastic friend.

A Product Still Looking For A Function

A Pepper earning an honest crust as a tourist guide at the Heijo Palace museum. Tokumeigakarinoaoshima, CC BY-SA 4.0.
A Pepper earning an honest crust as a tourist guide at the Heijo Palace museum. Tokumeigakarinoaoshima, CC BY-SA 4.0.

Pepper made its debut back in 2014, a diminutive and child-like robot with basic speech recognition and conversation skills, the ability to recognize some facial expressions, and a voice to match those big manga-style eyes. It was a robot built for personal interaction rather than work, as those soft tactile hands are better suited to a handshake than holding a tool. It found its way into Softbank stores as well as a variety of other retail environments, it was also used in experiments to assess whether it could work as a companion robot in medical settings, and it even made an appearance as a cheerleading squad. It didn’t matter that it was found to be riddled with insecurities, it very soon became a favourite with media tech pundits, but it remained at heart a product that was seeking a purpose rather than one ready-made to fit a particular function.

I first encountered a Pepper in 2016, at the UK’s National Museum of Computing. It was simply an exhibit under the watchful eye of a museum volunteer rather than being used to perform a job, and it shared an extremely busy gallery with an exhibit of Acorn classroom computers from the 1980s and early ’90s. It was an odd mix of the unexpected and the frustrating, as it definitely saw me and let me shake its hand but stubbornly refused to engage in conversation. Perhaps it was taking its performance as a human child seriously and being shy, but the overwhelming impression was of something that wasn’t ready for anything more than experimental interaction except via its touch screen. As a striking contrast in 2016 the UK saw the first release of the Amazon Echo, a disembodied voice assistant that might not have had a cute face but which could immediately have meaningful interactions with its owner.

How Can A Humanoid Robot Compete With A Disembodied Voice?

In comparing the Pepper with an Amazon Echo it’s possible that we’ve arrived at the root of the problem. Something that looks cool is all very well, but without immediate functionality, it will never capture the hearts of customers. Alexa brought with it the immense power of Amazon’s cloud computing infrastructure, while Pepper had to make do with whatever it had on board. It didn’t matter to potential customers that a cloud-connected microphone presents a huge privacy issue, for them a much cheaper device the size of a hockey puck would always win the day if it could unfailingly tell them the evening’s TV schedule or remind them about Aunty’s birthday.

Over the next decade we will see the arrival of affordable and compact processing power that can do more of the work for which Amazon currently use the cloud. Maybe Pepper will never fully receive that particular upgrade, but it’s certain that if Softbank don’t do it then somebody else will. Meanwhile there’s a reminder from another French company that being first and being cute in the home assistant market is hardly a guarantee of success, who remembers the Nabaztag?

Header: Tokumeigakarinoaoshima, CC0.

ESP32 Turned Handy SWD Flasher For NRF52 Chips

Got an nRF52 or nRF51 device you need to flash? Got an ESP32 laying around collecting dust? If so, then firmware hacking extraordinaire [Aaron Christophel] has the open source code you need. His new project allows the affordable WiFi-enabled microcontroller to read and write to the internal flash of Nordic nRF52 series chips via their SWD interface. As long as you’ve got some jumper wires and a web browser, you’re good to go.

In the first video below [Aaron] demonstrates the technique with the PineTime smartwatch, but the process will be more or less the same regardless of what your target device is. Just connect the CLK and DIO lines to pins GPIO 21 and GPIO 19 of the ESP32, point your web browser to its address on the local network, and you’ll be presented with a straightforward user interface for reading and writing the chip’s flash.

As demonstrated in the second video, with a few more wires and a MOSFET, the ESP32 firmware is also able to perform a power glitch exploit on the chip that will allow you to read the contents of its flash even if the APPROTECT feature has been enabled. [Aaron] isn’t taking any credit for this technique though, pointing instead to the research performed by [LimitedResults] to explain the nuts and bolts of the attack.

We’re always excited when a message from [Aaron] hits the inbox, since more often that not it means another device has received an open source firmware replacement. From his earlier work with cheap fitness trackers to his wildly successful Bluetooth environmental sensor hacking, we don’t think this guy has ever seen a stock firmware that he didn’t want to immediately send to /dev/null.

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Social Engineering And Menus

If you follow cybersecurity hacker methods — or just watch Mr. Robot — you probably know that the best way to get someone’s password is to ask for it. Sure, you probably can’t just say “Hi, I’m a bad guy. Can I have your password?” But there are all sorts of tricks you can use like pretending to be in the person’s IT department, someone in management, or by making up a crisis to overcome their better judgement with a sense. But of course, as wise computer people, we are immune to such things, right? We also don’t need those kinds of tricks in our arsenal.

Is that true? It is amazing how many subtle things influence what we think are rational decisions, no matter who we are. Consider going to eat in a restaurant. Simple, right? You look at the menu, pick what you want, and order. No one is influencing you. But they are. According to a BBC article, there’s a whole industry of menu “engineering” that figures out how to get you to order pricey food.

You might not think social engineering for menus is a great skill for us. But maybe your new open source project needs collaborators. Maybe your startup company needs investors. Maybe you’d like someone to look at your resume. Maybe the same tricks that work with diners will work in those cases, too.

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Kathleen Lonsdale Saw Through The Structure Of Benzene

The unspoken promise of new technologies is that they will advance and enhance our picture of the world — that goes double for the ones that are specifically designed to let us look closer at the physical world than we’ve ever been able to before. One such advancement was the invention of X-ray crystallography that let scientists peer into the spatial arrangements of atoms within a molecule. Kathleen Lonsdale got in on the ground floor of X-ray crystallography soon after its discovery in the early 20th century, and used it to prove conclusively that the benzene molecule is a flat hexagon of six carbon atoms, ending a decades-long scientific dispute once and for all.

Benzene is an organic chemical compound in the form of a colorless, flammable liquid. It has many uses as an additive in gasoline, and it is used to make plastics and synthetic rubber. It’s also a good solvent. Although the formula for benzene had been known for a long time, the dimensions and atomic structure remained a mystery for more than sixty years.

Kathleen Lonsdale was a crystallography pioneer and developed several techniques to study crystal structures using X-rays. She was brilliant, but she was also humble, hard-working, and adaptable, particularly as she managed three young children and a budding chemistry career. At the outbreak of World War II, she spent a month in jail for reasons related to her staunch pacifism, and later worked toward prison reform, visiting women’s prisons habitually.

After the war, Kathleen traveled the world to support movements that promote peace and was often asked to speak on science, religion, and the role of women in science. She received many honors in her lifetime, and became a Dame of the British Empire in 1956. Before all of that, she honored organic chemistry with her contributions.

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