ESP32 Video Input Using I2S

August 23, 2021 by 5 Comments

Computer engineering student [sherwin-dc] had a rover project which required streaming video through an ESP32 to be accessed by a web server. He couldn’t find documentation for the standard camera interface of the ESP32, but even if he had it, that approach used too many I/O pins. Instead, [sherwin-dc] decided to shoe-horn a video into an I2S stream. It helped that he had access to an Altera MAX 10 FPGA to process the video signal from the camera. He did succeed, but it took a lot of experimenting to work around the limited resources of the ESP32. Ultimately [sherwin-dc] decided on QVGA resolution of 320×240 pixels, with 8 bits per pixel. This meant each frame uses just 77 KB of precious ESP32 RAM.

His design uses a 2.5 MHz SCK, which equates to about four frames per second. But he notes that with higher SCK rates in the tens of MHz, the frame rate could be significantly higher — in theory. But considering other system processing, the ESP32 can’t even keep up with four FPS. In the end, he was lucky to get 0.5 FPS throughput, but that was adequate for purposes of controlling the rover (see animated GIF below the break). That said, if you had a more powerful processor in your design, this technique might be of interest. [Sherwin-dc] notes that the standard camera drivers for the ESP32 use I2S under the hood, so the concept isn’t crazy.

We’ve covered several articles about generating video over I2S before, including this piece from back in 2019. Have you ever commandeered a protocol for “off-label” use?

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Open-Source Insulin: Biohackers Aiming For Distributed Production

August 23, 2021 by 76 Comments

When you’ve got a diabetic in your life, there are few moments in any day that are free from thoughts about insulin. Insulin is literally the first coherent thought I have every morning, when I check my daughter’s blood glucose level while she’s still asleep, and the last thought as I turn out the lights, making sure she has enough in her insulin pump to get through the night. And in between, with the constant need to calculate dosing, adjust levels, add corrections for an unexpected snack, or just looking in the fridge and counting up the number of backup vials we have on hand, insulin is a frequent if often unwanted intruder on my thoughts.

And now, as my daughter gets older and seeks like any teenager to become more independent, new thoughts about insulin have started to crop up. Insulin is expensive, and while we have excellent insurance, that can always change in a heartbeat. But even if it does, the insulin must flow — she has no choice in the matter. And so I thought it would be instructional to take a look at how insulin is made on a commercial scale, in the context of a growing movement of biohackers who are looking to build a more distributed system of insulin production. Their goal is to make insulin affordable, and with a vested interest, I want to know if they’ve got any chance of making that goal a reality.

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Math, Optics, And CNC Combine To Hide Secret Images In Acrylic

August 23, 2021 by 45 Comments

Magic mirrors, with an LCD panel hidden behind a partially reflectively mirror, are popular for a reason — they’re a good-looking way to display useful information. A “Magic Window,” however, is an entirely different thing — and from the look of it, a far cooler one.

If you’ve never seen a Magic Window before, don’t worry — it’s partially because you’re not supposed to see it. A Magic Window appears to be a clear piece of glass or plastic, one with a bit of a wave in it that causes some distortion when looking through it. But as [Matt Ferraro] explains, the distortion encodes a hidden image, visible only when light passes through the window. It looks a bit like a lithophane, but it’s projected rather than reflected, and it relies on an optical phenomenon known as caustics. If you’ve ever seen the bright and dark patches cast on the bottom of a swimming pool when sunlight hits the surface, you’ve seen caustics.

As for how to hide an image in a clear window, let’s just say it takes some doing. And some math; Snell’s Law, Fermat’s Theorem, Poisson’s Equation — all these and more are mentioned by [Matt] by way of explanation. The short story is that an image is morphed in software, normalized, and converted into a heightmap that’s used to generate a toolpath for a CNC router. The design is carved into a sheet of acrylic by the router and polished back to clarity with a succession of sandpaper grits. The wavy window is then ready to cast its hidden shadow.

Honestly, the results are amazing, and we marvel at the skills needed to pull this off. Or more correctly, that [Matt] was able to make the process simple enough for anyone to try.

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PS2 Gets The Ginger Portable Treatment

August 23, 2021 by 14 Comments

The first thing we notice about this portable PS2 is that the plastic looks like a consumer-grade shell, not a 3D printed case. It comes from [GingerOfOz], who has lots of portable conversions under his belt, so we are not surprised this looks like a genuine Sony device. When you are as experienced as he, details like plastic texture, and button selection, are solved problems, but shouldn’t be taken for granted by us mortals.

Of course, this isn’t just pretty, and if it weren’t functional, we wouldn’t be talking about it. The system plays nearly all PS2 titles from USB memory. The notable exceptions are the ones that refuse to load without a Dualshock controller. Rude. If you’re wondering if it plays games at full speed, yes. It achieves authentic speed because it uses a PS2 slim motherboard which gets cut down by a Dremel. Custom PCBs provide the rest of the hardware, like volume buttons and battery charging. There is no optical drive since they are power hogs, so your cinematic cut scenes may lag, and load times are a little longer.

Modern mobile phones are one of the most powerful gaming systems ever built, but there is something about purpose-built portable gaming hardware that just feels right. You know?

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Etch-a-sketch made with LEDs

RGB LED Matrix Helps Etch-a-Sketch Scratch Out A 21st Century Existence

August 22, 2021 by 3 Comments

We never did crack open our Etch-a-Sketch, but we did scrape out a window large enough to really check out the mechanism inside. [MrLangford] is bringing the Etch-a-Sketch into the 21st century while at the same time, bringing an even bigger air of mystery, at least for the normies.

Instead of scraping aluminum powder off of plastic by driving a stylus on an x-y gantry with a pair of knobs, this bad boy uses rotary encoders to move the cursor around and put down squares of colored light. The familiar movements are there — the left knob moves the cursor left and right, and the right knob moves it up and down. But this wouldn’t be a 21st century toy without newfangled features. Push the left encoder down and it cycles through eight color choices, or push the right one down to go through them backwards. We hope one of the colors is setting it back to darkness in case you screw up. And while we’re dreaming up improvements, it would be awesome to add an accelerometer so you could shake it clear like a standard Etch-a-Sketch.

Inside the requisite red enclosure with white knobs are an Arduino Nano and a 16×16 RGB LED matrix. The enclosure is four sheets of 6mm MDF glued together, and we like the use of protoboard to distribute GND and 5 V in the name of keeping the thing slim.

If you’re not much of an artist, here’s a TV-sized Etch-a-Sketch build that can draw by itself.

Nixie Robot Head with LED eyes and retro-futuristic design

Artful Nixie Bot Sculpture Sees, Thinks, And Talks

August 22, 2021 by No comments

When [Tavis] and his father were inspired to lend their talents to building a robot sculpture, they split the duties. [Tavis]’ father built a robot head, and [Tavis] utilized designs old and new to breathe life into their creation.

Many a hardware hacker has been inspired by robotic art over the years. Whether it’s the vivid descriptions by the likes of Asimov and Clarke, the magnificent visuals from the formative 1927 film Metropolis, or the frantic arm-waving Robot from Lost In Space, the robots of Science Fiction have impelled many to bring their own creations to life.

For [Travis]’s creation, Two rare Russian Nixie Tubes in the forehead convey what’s on the robot’s mind, while dual 8×8 LED matrices from Adafruit give the imagination a window to the binary soul. A sound board also from Adafruit gives voice to the automaton, speaking wistful words in a language known only to himself.

A DC to DC converter raises the LiPo supplied 3.7v to the necessary 170v for the Nixies, and a hidden USB-C port charges the battery once its two-hour life span has expired. Two custom Nixie driver boards are each host to an Arduino Pro Micro, and [Tavis] has made the PCB design available for those wishing to build their own Nixie projects.

As you can see in the video below the break, the results are nothing short of mesmerizing!

Of course, we’re no strangers to robots here at Hackaday. Perhaps we can interest you in a drink created by the industrial-grade Robotic Bartender while you consider the best way to Stop the Robot Uprising. And remember, if you spot any awesome hacks, let us know via the Tip Line!

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Hackaday Links: August 22, 2021

August 22, 2021 by 22 Comments

It’s usually pretty hard to miss when Boston Dynamics drops a new video of one or more of their robots doing something flashy. But in case you’ve been under a rock the last few days, you might want to check out the Atlas parkour video. We last saw a pair of Atlas robots busting some dance moves with a few other Boston Dynamics robots, and while that was an incredible demonstration of the level of control they’ve engineered, they really were just playing back a series of preprogrammed moves. The obstacle course demo, though, seems like something different. There’s a good overview of the demo in IEEE Spectrum, where they point out that this is the first time we’ve seen Atlas show off using all four limbs at once for coordinated motion — that sweet vault over the fence. And really, it’s hard not to watch such human-like moves and not think that it’s just somebody in a robot suit. Even the stumbles feel human. What’s even more fun, though, is the behind-the-scenes look at Atlas. Especially for the face-plants and fails.

August 19 was the 100th anniversary of the birth of Gene Roddenberry, the creator of Star Trek. In the process of just trying to build a fictional universe to tell some interesting stories and make a little money, he managed to spawn not only an enduring science-fiction franchise but also to inspire generations of future scientists and engineers. The number of things that Star Trek writers invented to move their stories along that later showed up as actual products is astonishing, as are the weird coincidences like placing the fictional planet Vulcan in orbit around star 40 Eridani, only to find out that there’s actually a potentially habitable exoplanet circling that star. As a salute to Roddenberry, the Deep Space Network was used last week to send a message to 40 Eridani. One of the big dishes at the Goldstone DSN site in California blasted the 20-kW signal out on Thursday, starting it on its 16.5-year journey to the stars. We looked for details on what was sent, but the only description was that it contained a 1976 recording by the Great Bird of the Galaxy himself. Whatever it was, it’ll take at least 33 years to see if we get a response. Mark your calendars.

I’ve been doing a lot of work on cars lately, a task made considerably more approachable by the fact that the newest vehicle in the family fleet is from 2004. I find working on cars very satisfying, and I’m dreading the day when we’re forced to replace one of our old-timers with something more modern and less amenable to driveway repairs. That said, there’s also a lot to like about newer vehicles, particularly electric vehicles. It would be nice to have a way to move away from ICE vehicles while still being able to work on your ride. But if Ford’s tease this week of an EV crate motor comes to pass, it just might be the best of both worlds. The motor, bearing the unfortunate moniker “Eluminator” — just can’t resist putting that “E” in there, can they? — is supposed to be a drop-in replacement for an internal combustion engine, suitable for a “restomod” project. These car builds aim to make a car look as vintage as possible, but radically change the guts to add functionality — think a Raspberry Pi running a Spotify client that’s stuffed into a vintage Atwater Kent cathedral radio. We like the idea of electrifying an old car, but it seems to us that a crate motor is only part of the answer. Is there such thing as a crate battery?

And finally, there was an interesting article detailing a new approach to repairing ruptured eardrums using 3D printing. The tympanic membrane is a thin, delicate sheet of tissue that is easily punctured, whether by blunt-force trauma, infections, or even by loud sounds like gunshots or explosions. Hearing is compromised when an eardrum is damaged, and the hole can serve as a route for pathogenic microorganisms to get into the inner ear. Fixing the hole usually requires a graft from the patient’s own tissues, often sourced from the little dongle covering the ear canal. But this tissue isn’t nearly as thin as the natural eardrum, and while hearing can be restored, it’s often muddy and muffled. The new technique is to 3D-print a custom graft for the patient, using a special polymer and printer. The artificial membrane mimics the structure of the natural tympanic membrane and restores more natural hearing immediately. It also serves as a scaffold for the body to fill in with natural cells, hopefully returning natural function as the 3D-printed part is absorbed. It’s interesting work, and the video in the linked article is pretty fascinating too.