Dot-Matrix Printer Brings Old School Feel To Today’s Headlines

If you remember a time when TV news sets universally incorporated a room full of clattering wire service teleprinters to emphasize the seriousness of the news business, congratulations — you’re old. Now, most of us get our news piped directly into our phones, selected by algorithms perfectly tuned to rile us up on whatever the hot-button issue du jour happens to be. Welcome to the future.

If like us you long for a simpler way to get your news, [Andrew Schmelyun] has a partial solution with this dot-matrix news feeder. It’s part of his effort to detox a bit from the whole algorithm thing and make the news a little more concrete. He managed to chase down a very old Star Micronics printer with a serial interface, which he got on the cheap thanks to the previous owner not being sure if it worked. It did, at least after some cleaning, and thanks to a USB-to-serial and the efforts of Linux kernel hackers through the ages, was able to echo output to the printer from a Raspberry Pi Zero W.

From there, getting a daily news feed was as simple as writing some PHP code to mine the APIs of a few selected services. We’re perplexed and alarmed to report that Hackaday is not among the selected sources, but we’re sure this was just a small oversight that will be corrected in version 2. The program runs as a cron job so that a dead-tree version of the day’s top stories is ready for [Andrew]’s morning coffee.

We’ve seen similar news printers before; we particularly like this roll-feed paper version. But for a seriously retro feel, we’d love to see this done on a real teletype.

Recycling Tough Plastics Into Precursors With Some Smart Catalyst Chemistry

Plastics are unfortunately so cheap useful that they’ve ended up everywhere. They’re filling our landfills, polluting our rivers, and even infiltrating our food chain as microplastics. As much as we think of plastic as recyclable, too, that’s often not the case—while some plastics like PET (polyethylene terephthalate) are easily reused, others just aren’t.

Indeed, the world currently produces an immense amount of polyethylene and polypropylene waste. These materials are used for everything from plastic bags to milk jugs and for microwavable containers—and it’s all really hard to recycle. However, a team at UC Berkeley might have just figured out how to deal with this problem.

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Hack On Self: The Alt-Tab Annihilator

Last time, I told you about a simple script I made to collect data about my laptop activity, talked about why collecting data about yourself is a moral imperative, and shared the upgraded script with you alongside my plans for it. Today, I will show you a problem I’ve been tackling, with help of this script and the data it gives, and I also would love to hear your advice on a particular high-level problem I’m facing.

Today’s problem is as old as time – I often can’t focus on tasks I badly need done, even ones I want done for myself. This has been a consistent problem in my life, closing off opportunities, getting me to inadvertently betray my friends and family, hurting my health and well-being, reinforcing a certain sort of learned helplessness, and likely reinforcing itself as it goes, too.

It’s deeply disturbing to sit down fully intending to work on a project, then notice no progress on it hours later, and come to a gut-wrenching realization you’ve had hundreds of such days before – I think this screws with you, on a fundamental level. Over the years, I’ve been squeezing out lessons from this failure mode, making observations, trying out all sorts of advice, in search of a solution.

Join me today in non-invasive brain augmentation and reprogramming, as I continue trying to turn my life around – this time, with help of my laptop, a computer that I already spend a ton of time interfacing with. Ever notice that starting work on a task  is often the hardest part of it? It’s the same for me, and I decided to hack away at it.

Staying On Track

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Automated Pixel Art With Marbles

Marble machines are a fun and challenging reason to do engineering for the sake of engineering. [Engineezy] adds some color to the theme, building a machine to create 16×16 marble images automatically. (Video embedded below.)

The core problem was devising ways to sort, lift, place, and dump marbles in their correct positions without losing their marbles—figuratively and literally. Starting with color detection, [Engineezy] used an RGB color sensor and Euclidian math to determine each marble’s color. After trying several different mechanical sorting mechanisms, he settled on a solenoid and servo-actuated dump tube to drop the marble into the appropriate hopper.

After sorting, he faced challenges with designing a mechanism to transport marbles from the bottom hoppers to the top of the machine. While paddle wheels seemed promising at first, they tended to jam—a problem solved by innovating with Archimedes screws that move marbles up smoothly without clogs. The marbles are pushed into clear tubes on either side of the machine, providing a clear view of their parade to the top.

Perhaps most ingenious is his use of constant-force springs as a flexible funnel to guide the marbles to a moving slider that drops them into the correct column of the display. When a picture is complete, sliding doors open on the bottom of the columns, dumping the marbles into a chain lift which feeds them into the sorting section. Each of the mechanisms has a mirrored version of the other side, so the left and right halves of the display operate independently.

The final product is slow, satisfying and noisy kinetic testament to [Engineezy]’s perseverance through countless iterations and hiccups.

Marble machines can range from minimalist to ultra-complex musical monstrosities, but never fail to tickle our engineering minds. Continue reading “Automated Pixel Art With Marbles”

On The Nature Of Electricity: Recreating The Early Experiments

Bits of material levitating against gravity, a stream of water deflected by invisible means, sparks of light appearing out of thin air; with observations like those, it’s a wonder that the early experiments into the nature of electricity progressed beyond the catch-all explanation of magic. And yet they did, but not without a lot of lamb’s bladders and sulfur globes, and not a little hand waving in the process. And urine — lots and lots of urine.

Looking into these early electrical experiments and recreating them is the unlikely space [Sam Gallagher] has staked out with the “Experimental History of Electricity,” a growing playlist on his criminally undersubscribed YouTube channel. The video linked below is his latest, describing the apparatus one Francis Hauksbee used to generate static electric charges for his early 18th-century experiments. Hauksbee’s name is nowhere near as well-known as that of Otto von Guericke or William Gilbert, who in the two centuries before Hauksbee conducted their own experiments and who both make appearances in the series. But Hauksbee’s machine, a rotating glass globe charged by the lightest touch of a leather pad, which [Sam] does a fantastic job recreating as closely as possible using period-correct materials and methods, allowed him to explore the nature of electricity in much greater depth than his predecessors.

But what about the urine? As with many of the experiments at the time, alchemists used what they had to create the reagents they needed, and it turned out that urine was a dandy source of phosphorous, which gave off a brilliant light when sufficiently heated. The faint light given off by mercury when shaken in the vacuum within a barometer seemed similar enough that it became known as the “mercurial phosphor” that likely inspired Hauksbee’s electrical experiments, which when coupled with a vacuum apparatus nearly led to the invention of the mercury discharge lamp, nearly 200 years early. The more you know. Continue reading “On The Nature Of Electricity: Recreating The Early Experiments”

A Lightweight Balloon Tracker For High Altitude Missions

It’s pretty easy to take a balloon, fill it up with helium, and send it up in to the upper atmosphere. It’s much harder to keep track of it and recover it when it falls back to Earth. If you’re trying to do that, you might find some value in the Tiny4FSK project from the New England Weather Balloon Society.

Tiny4FSK is intended to be a very small solution for high-altitude tracking. As you might have guessed from the name, it communicates via 4FSK—four frequency shift keying. Basically, it communicates data via four separate tones. Based around the SAMD21G18A microcontroller, it’s designed to run on a single AA battery, which should last for anywhere from 10-17 hours. It communicates via a Si4063 transmitter set up to communicate on 433.2 MHz, using the Horus Binary v2 system. As for data, it’s hooked up with a GPS module and a BME280 environmental sensor for location. The balloon can figure out where it is, and tell you the temperature, pressure, and humidity up there, too.

If you’re looking for a lightweight balloon tracker, this one might be very much up your alley. We’ve featured other projects in this vein, too. Meanwhile, if you’re developing something new in the high-altitude ballooning space, you could keep it to yourself. Or, alternatively, you could tell us via the tipsline and we’ll tell everybody else. Your call!

Doing 1080p Video, Sort Of, On The STM32 Microcontroller

When you think 1080p video, you probably don’t think STM32 microcontroller. And yet! [Gabriel Cséfalvay] has pulled off just that through the creative use of on-chip peripherals. Sort of.

The build is based around the STM32L4P5—far from the hottest chip in the world. Depending on the exact part you pick, it offers 512 KB or 1 Mbyte of flash memory, 320 KB of SRAM, and runs at 120 MHz. Not bad, but not stellar.

Still, [Gabriel] was able to push 1080p at a sort of half resolution. Basically, the chip is generating a 1080p widescreen RGB VGA signal. However, to get around the limited RAM of the chip, [Gabriel] had to implement a hack—basically, every pixel is RAM rendered as 2×2 pixels to make up the full-sized display. At this stage, true 1080p looks achievable, but it’ll be a further challenge to properly fit it into memory.

Output hardware is minimal. One pin puts out the HSYNC signal, another handles VSYNC. The same pixel data is clocked out over R, G, and B signals, making all the pixels either white or black. Clocking out the data is handled by a nifty combination of the onboard DMA functionality and the OCTOSPI hardware. This enables the chip to hit the necessary data rate to generate such a high-resolution display.

There’s more work to be done, but it’s neat to see [Gabriel] get even this far with such limited hardware. We’ve seen others theorize similar feats on chips like the RP2040 in the Pi Pico, too. Video after the break.

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