Historical Hackers: Emergency Antennas Launched By Kite

Your airplane has crashed at sea. You are perched in a lifeboat and you need to call for help. Today you might reach for a satellite phone, but in World War II you would more likely turn a crank on a special survival radio.

These radios originated in Germany but were soon copied by the British and the United States. In addition to just being a bit of history, we can learn a few lessons from these radios. The designers clearly thought about the challenges stranded personnel would face and came up with novel solutions. For example, how do you loft a 300-foot wire up to use as an antenna? Would you believe a kite or even a balloon?

Continue reading “Historical Hackers: Emergency Antennas Launched By Kite”

Scanner Captures View-Master Discs As Glorious 3D Videos

The toys of the past may have been cheesy, but you can’t deny the creativity needed to build something engaging without any electronics. One stalwart toy from this category is View-Master, the little stereoscopic slide viewer that brought the world to life in seven vibrant scenes. And digitizing these miniature works of art is the purpose of this neat View-Master reel scanner project.

If you haven’t had the pleasure of using a View-Master, the gist is that a flat cardboard disc ringed with 14 color transparencies was inserted into a plastic viewer. Binocular eyepieces showed scenes from opposing pairs of slides, which were illuminated by a frosted screen and room lighting. The scenes were photographed from slightly different angles, leading to a stereoscopic image that was actually pretty good quality.

In the video below, project creator [W. Jason Altice] describes View-Master as “the YouTube of the 1950s.” We partially agree; with only seven frames to tell a story, we’d say it’s more like TikTok than YouTube. Regardless, capturing these mini-movies requires quite a bit of complexity. All the parts for the reel carousel are 3D-printed, with a small stepper to advance the reel and an optical sensor to register its position. A ring of RGB LEDs beneath the reel illuminates the slides; being able to control the color of the light helps with color balancing for slides with faded colors. An 8-megapixel camera captures each slide, and some pretty slick software helps with organizing the image pairs, tweaking their alignment, capturing the captions from the disc, and stitching everything into a video.

There’s a whole YouTube channel devoted to View-Master captures, which are best viewed with a Google Cardboard or something similar. Even without the 3D effect, it’s still pretty cool to watch [Popeye] beat up a nuke again.

Continue reading “Scanner Captures View-Master Discs As Glorious 3D Videos”

Simple Encryption You Can Do On Paper

It’s a concern for Europeans as it is for people elsewhere in the world: there have been suggestions among governments to either outlaw, curtail, or backdoor strong end-to-end encryption. There are many arguments against ruining encryption, but the strongest among them is that encryption can be simple enough to implement that a high-school student can understand its operation, and almost any coder can write something that does it in some form, so to ban it will have no effect on restricting its use among anyone who wants it badly enough to put in the effort to roll their own.

With that in mind, we’re going to have a look at the most basic ciphers, the kind you could put together yourself on paper if you need to.

Continue reading “Simple Encryption You Can Do On Paper”

Mind-Controlled Flamethrower

Mind control might seem like something out of a sci-fi show, but like the tablet computer, universal translator, or virtual reality device, is actually a technology that has made it into the real world. While these devices often requires on advanced and expensive equipment to interpret brain waves properly, with the right machine learning system it’s possible to do things like this mind-controlled flame thrower on a much smaller budget. (Video, embedded below.)

[Nathaniel F] was already experimenting with using brain-computer interfaces and machine learning, and wanted to see if he could build something practical combining these two technologies. Instead of turning to an EEG machine to read brain patterns, he picked up a much less expensive Mindflex and paired it with a machine learning system running TensorFlow to make up for some of its shortcomings. The processing is done by a Raspberry Pi 4, which sends commands to an Arduino to fire the flamethrower when it detects the proper thought patterns. Don’t forget the flamethrower part of this build either: it was designed and built entirely by [Nathanial F] as well using gas and an arc lighter.

While the build took many hours of training to gather the proper amount of data to build the neural network and works as the proof of concept he was hoping for, [Nathaniel F] notes that it could be improved by replacing the outdated Mindflex with a better EEG. For now though, we appreciate seeing sci-fi in the real world in projects like this, or in other mind-controlled projects like this one which converts a prosthetic arm into a mind-controlled music synthesizer.

Continue reading “Mind-Controlled Flamethrower”

Testing 3D Printed Worm Gears

Worm gears are great if you have a low-speed, high-torque application in which you don’t need to backdrive. [Let’s Print] decided to see if they could print their own worm gear drives that would actually be usable in practice. The testing is enlightening for anyone looking to use 3D printed gearsets. (Video, embedded below.)

The testing involved printing worm gears on an FDM machine, in a variety of positions on the print bed in order to determine the impact of layer orientations on performance. Materials used were ABS, PLA and PETG. Testing conditions involved running a paired worm gear and worm wheel at various rotational speeds to determine if the plastic parts would heat up or otherwise fail when running.

The major upshot of the testing was that, unlubricated, gears in each material failed in under two minutes at 8,000 RPM. However, with adequate lubrication from a plastic-safe grease, each gearset was able to run for over ten minutes at 12,000 RPM. This makes sense, given the high friction typical in worm gear designs. However, it does bear noting that there was little to no load placed on the gear train. We’d love to see the testing done again with the drive doing some real work.

It also bears noting that worm drives typically don’t run at 12,000 RPM, but hey – it’s actually quite fun to watch. We’ve featured some 3D printed gearboxes before too, pulling off some impressive feats. Video after the break.

Continue reading “Testing 3D Printed Worm Gears”

Play Your Favorite Nokia Game On The Raspberry Pi Pico

In many people’s memories, Snake lived and breathed on Nokia handsets from the late 90s and early 2000s. However, the game has been around for much longer than that, and will continue to live on in the future. That’s at least in part thanks to people like [Hari Wiguna] keeping it alive by implementing it on new platforms.

[Hari] set about writing Snake in MicroPython for the Raspberry Pi Pico. The hardware side of things is simple enough – five buttons hooked up to the Pico, along with an 128×64 I2C OLED screen to display the game on. On the software side of things, [Hari] pushed the boat out, deciding that his version of Snake had to have the player character slither like the real thing. This took a little effort to get right, particularly when navigating corners in different directions. However, perseverance paid off and [Hari] got the job done.

Code is on GitHub for those that want to tinker at home. It’s a tidy piece of work, though not the weirdest place we’ve seen the game appear – we’ve actually seen it run within PCB routing software before thanks to some nifty scripting. Video after the break. Continue reading “Play Your Favorite Nokia Game On The Raspberry Pi Pico”