Pocket Device Tracks Planets And The ISS

February 21, 2025 by 7 Comments

Ever been at a party and landed in a heated argument about exactly where the International Space Station (ISS) is passing over at that very instant? Me neither, but it’s probably happened to someone. Assuming you were in that situation, and lacked access to your smartphone or any other form of internet connected device, you might like the pocket-sized Screen Tracker from [mars91].

The concept is simple. It’s a keychain-sized item that combines an ESP32, a Neopixel LED, and a small LCD screen on a compact PCB with a couple of buttons. It’s programmed to communicate over the ESP32’s WiFi connection to query a small custom website running on AWS. That website processes orbit data for the ISS and the positions of the planets, so they can be displayed on the LCD screen above a map of the Earth. We’re not sure what font it uses, but it looks pretty cool—like something out of a 90s sci-fi movie.

It’s a great little curio, and these sort of projects can have great educational value to boot. Creating something like this will teach you about basic orbits, as well as how to work with screens and APIs and getting embedded devices online. It may sound trivial when you’ve done it before, but you can learn all kinds of skills pursuing builds like these.

Continue reading “Pocket Device Tracks Planets And The ISS” →

Hackaday Podcast Episode 309: Seeing WiFi, A World Without USB, Linux In NES In Animal Crossing

February 21, 2025 by 4 Comments

This week Hackaday Editors Elliot Williams and Tom Nardi start things off with updates on the rapidly approaching Hackaday Europe and the saga of everyone’s favorite 3D printed boat.

From there they’ll cover an impressive method of seeing the world via WiFi, Amazon’s latest changes to the Kindle ecosystem, and an alternate reality in which USB didn’t take over the peripheral world. You’ll also hear about a multi-level hack that brings the joys of Linux into the world of Animal Crossing, 3D printed circuit components, and the imminent release of KiCAD 9.

Stick around until the end to learn about a unique hardened glass from East Germany and the disappointing reality of modern voice control systems.

Where to Follow Hackaday Podcast

Places to follow Hackaday podcasts:

Download the DRM-free MP3 for safe keeping.

Continue reading “Hackaday Podcast Episode 309: Seeing WiFi, A World Without USB, Linux In NES In Animal Crossing” →

Building A One Wheel With Tracks

February 21, 2025 by 6 Comments

One-wheels use motion-tracking hardware and fine motor control to let you balance on a single wheel. That’s neat and all, but [Michael Rechtin] had another idea in mind—what if a one-wheel used a track instead?

The idea behind the track was to make the one-wheel more capable on surfaces where wheels simply can’t compete. The tracked drivetrain was largely 3D printed, including some massive gears that are supplemented by a big old 150 mm ball bearing which sits around the drive motor itself. If you love planetary gear trains with a 4:1 reduction, this project is for you. Carbon-fiber reinforced filament was used for many of the parts to give them some additional strength. Control is a little different than a traditional one-wheel, since the flat-bottomed track means lean controls won’t work. Instead, a wireless hand throttle was constructed to enable the rider to command the direction of travel.

It’s not easy to ride, but the one-track does actually work. It’s capable of crawling its way around on grass and snow quite well. There were some issues with the printed tracks and rollers, particularly when turning, but tweaks to round out the track profile helped solve that issue to a degree. There’s a reason we often use wheels instead of tracks, but somehow tracks are still just cool.

Continue reading “Building A One Wheel With Tracks” →

This Week In Security: OpenSSH, JumbledPath, And RANsacked

February 21, 2025 by 7 Comments

OpenSSH has a newly fixed pair of vulnerabilities, and while neither of them are lighting the Internet on fire, these are each fairly important.

The central observation made by the Qualsys Threat Research Unit (TRU) was that OpenSSH contains a code paradigm that could easily contain a logic bug. It’s similar to Apple’s infamous goto fail; SSL vulnerability. The setup is this: An integer, r, is initialized to a negative value, indicating a generic error code. Multiple functions are called, with r often, but not always, set to the return value of each function. On success, that may set r to 0 to indicate no error. And when one of those functions does fail, it often runs a goto: statement that short-circuits the rest of the checks. At the end of this string of checks would be a return r; statement, using the last value of r as the result of the whole function.

Continue reading “This Week In Security: OpenSSH, JumbledPath, And RANsacked” →

A New 8-bit CPU For C

February 21, 2025 by 60 Comments

It is easy to port C compilers to architectures that look like old minicomputers or bigger CPUs. However, as the authors of the Small Device C Compiler (SDCC) found, pushing C into a typical 8-bit CPU is challenging. Lessons learned from SDCC inspired a new 8-bit architecture, F8. This isn’t just a theoretical architecture. You can find an example Verilog implementation in the SDDC project and on GitHub. The name choice may turn out to be unfortunate as there was an F8 CPU from Fairchild back in the 1970s that apparently few people remember.

In the video from FOSDEM 2025, [Phillip Krause] provides a nice overview of the how and why of F8. While it might seem odd to create a new 8-bit CPU when you can get bigger CPUs for pennies, you have to consider that 8-bit machines are more than enough for many jobs, and if you can squeeze one into an FPGA, it might be a good choice as opposed to having to get a bigger FPGA to hold your design and a 32-bit CPU.

Continue reading “A New 8-bit CPU For C” →

Acoustic Engine Harnesses The Power Of Sound

February 21, 2025 by 33 Comments

If you think sonic booms from supersonic aircraft are a nuisance, wait until the sky is full of planes propelled by up-scaled versions of this interesting but deafening audio resonance engine.

Granted, there’s a lot of work to do before this “Sonic Ramjet” can fly even something as small as an RC plane. Creator [invalid_credentials] came up with the idea for a sound-powered engine after listening to the subwoofers on a car’s audio system shaking the paint off the body. The current design uses a pair of speaker drivers firing into 3D printed chambers, which are designed based on Fibonacci ratios to optimize resonance. When the speakers are driven with a low-frequency sine wave, the chambers focus the acoustic energy into powerful jets, producing enough thrust to propel a small wheeled test rig across a table.

It’s fair to ask the obvious question: is the engine producing thrust, or is the test model moving thanks to the vibrations caused by the sound? [invalid_credentials] appears to have thought of that, with a video showing a test driver generating a powerful jet of air. Downloads to STL files for both the large and small versions of the resonating chamber are provided, if you want to give it a try yourself. Just be careful not to annoy the neighbors too much.

Thanks to [cabbage] for the tip via [r/3Dprinting].

3D Print Yourself A Split Flap Display

February 20, 2025 by 8 Comments

Split flap displays! They’re mechanical, clickety-clackity, and largely commercially irrelevant in our screen-obsessed age. That doesn’t mean you can’t have a ball making one of your own, though! [Morgan Manly] did just that, with tidy results.

An ESP32 C3 SuperMini serves as the boss of the operation, running the whole display. The display is designed to be modular, so you can daisy chain multiple characters together to spell longer words. Each module has 37 characters, so it can display the alphabet, numerals 0 to 9, and a blank. Each module contains a 28BYJ-48 stepper motor for controlling the flaps, and a ULN2003 driver board to run it and a PCF8575 IO expander to handle communciation. An A3144 hall effect sensor is also used for positional feedback to ensure the display always shows the right character. The flap mechanism itself is relatively straightforward—a drum with all 37 flaps is until the correct character is reached, with the blank flaps hosting a magnet to trigger the aforementioned hall effect sensor. The flaps themselves are 3D-printed, with filament changes used to color the characters against the background.

If you’ve ever dreamed of building a flap-display clock or ticker, you needn’t dream of finding the perfect vintage example. You can just build your own! The added bonus is that you can make it as big or as small as you like. We’ve seen some interesting variations on the split flap concept recently, too. If you’re cooking up your own kooky electromechanical displays, don’t hesitate to let us know!