Hacker Tools, Hacked Tools

December 14, 2024 by Elliot Williams 3 Comments

We just love a good DIY tool project, and more so when it’s something that we can actually use cobbled together from stuff in our closet, or hacked out of cheap “toys”. This week we saw both a superb Pi Pico-based logic analyzer and yet another software frontend for the RTL-SDR dongle, and they both had us thinking of how good we have it.

If you don’t already have a logic analyzer, or if you have one of those super-cheap 8-channel jobbies, it might be worth your while to check out the Pico firmware simply because it gets you 24 channels, which is more than you’ll ever need™. At the low price of $4, maybe a little more if you need to add level shifters to the circuit to allow for 5 V inputs, you could do a lot worse for less than the price of a fancy sweet coffee beverage.

And the RTL dongle; don’t get us started on this marvel of radio hacking. If you vaguely have interest in RF, it’s the most amazing bargain, and ever-improving software just keeps adding functionality. The post above adds HTML5 support for the RTL-SDR, allowing you to drive it with code you host on a web page, which makes the entire experience not only cheap, but painless. Talk about a gateway drug! If you don’t have an RTL-SDR, just go out and buy one. Trust me.

What both of these hacker tools have in common, of course, is good support by a bunch of free and open software that makes them do what they do. This software enables a very simple piece of hardware to carry out what used to be high-end lab equipment functions, for almost nothing. This has an amazing democratizing effect, and paves the way for the next generation of projects and hackers. I can’t think of a better way to spend $20.

A Self Balancing Bike For Crash Dummy Billy

December 14, 2024 by Al Williams 22 Comments

We aren’t sure there’s enough information in the [We Make Machines’] video to easily copy their self-balancing bike project, but if you want to do something similar, you can learn a lot from watching the video. Building sufficient gyros to keep the bike stable required quite a bit of trial and error.

There are some tricks to getting a stable heavy weight to rotate without a lot of vibration and problems. The gyros go on the rider’s saddle, so you aren’t going to be able to ride in the normal fashion. However, a substantial motor drives the wheels so there’s no need to pedal.

The first attempt to self-balance stayed stable for about 10 seconds. Some of it was fine-tuning code, but noise from the gyros also threw off the angle sensor. A higher-quality sensor seemed promising, but it didn’t really fix the problem. Instead of using PID, the guys tried an LQR (Linear Quadratic Regulator) algorithm. Once that was sorted and a servo allowed for steering, it was time to let the bike roam free.

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A small mood/busy indicator attached to a laptop.

Personal Traffic Light Stops Them In Their Tracks

December 14, 2024 by Kristina Panos 30 Comments

Working from home can be pretty cool, but if you’re not the only one in the house trying to do it, the whole situation can feel like you’re right back in the office with all those walking, talking distractions. Except they’re in pajamas instead of business casual.

So, what’s the answer? Many times it’s not practical to stop what you’re doing, especially just to communicate that you’re busy. We suppose you could glare at them, put up your hand, or even give a dismissive wave, but a better solution might be this mood signal built by [gokux].

Through a simple web app, you can be red to indicate that you’re super busy, yellow to mean busy-ish, and green for let’s gossip about the cats.

This mood indicator is built on the Seeed Xiao ESP32-C3 and shows the given mood indicator on a small matrix of sixteen WS2812B LEDs. It’s powered by a 600 mAh, 3.7 V battery and a small push button switch. As usual, [gokux] has grade-A instructions for building your own version of this slick solution.

Would you like something more tactile and low-tech? Check out our own [Bob Baddeley]’s free/busy indicator from the lockdown days.

Origami-Inspired, Self-locking Structures With 3D Printing

December 13, 2024 by Donald Papp 2 Comments

Researchers recently shared details on creating foldable, self-locking structures by using multi-material 3D printing. These origami-inspired designs can transition between flat and three-dimensional forms, locking into place without needing external support or fasteners.

The 3D structure of origami-inspired designs comes from mountain and valley fold lines in a flat material. Origami designs classically assume a material of zero thickness. Paper is fine, but as the material gets thicker things get less cooperative. This technique helps avoid such problems.

An example of a load-bearing thick-film structure.

The research focuses on creating so-called “thick-panel origami” that wraps rigid panels in a softer, flexible material like TPU. This creates a soft hinge point between panels that has some compliance and elasticity, shifting the mechanics of the folds away from the panels themselves. These hinge areas can also be biased in different ways, depending on how they are made. For example, putting the material further to one side or the other will mechanically bias that hinge to fold into either a mountain, or a valley.

Thick-panel origami made in this way paves the way towards self-locking structures. The research paper describes several different load-bearing designs made by folding sheets and adding small rigid pieces (which are themselves 3D printed) to act as latches or stoppers. There are plenty of examples, so give them a peek and see if you get any ideas.

We recently saw a breakdown of what does (and doesn’t) stick to what when it comes to 3D printing, which seems worth keeping in mind if one wishes to do some of their own thick-panel experiments. Being able to produce a multi-material object as a single piece highlights the potential for 3D printing to create complex and functional structures that don’t need separate assembly. Especially since printing a flat structure that can transform into a 3D shape is significantly more efficient than printing the finished 3D shape.

Walkie Talkies, Jedi Style: Building A Communicator

December 13, 2024 by Heidi Ulrich 6 Comments

Playing Star Wars Outlaws sparked an idea with [3DSage]: why not recreate the game’s wrist communicator as a functioning gadget? Inspired by the relatively simplistic design, he and his friend Ben set out to build their own device to take to Galaxy’s Edge in Disneyland. Armed with an arsenal of tools—3D printers, CNC machines, and soldering irons—he aimed to turn imagination into reality.

After ordering multiple walkie-talkies, they meticulously tested each one for audio quality, circuit board size, and compatibility with custom components. The ‘world’s tiniest walkie-talkie’ had potential but demanded creative modifications, including disassembling and resoldering components. They crafted their own circuit board and designed a 3D printed housing to fit both electronics and style. For the finishing touch, they weathered the device with paints and even glow-in-the-dark accents, making it authentic to the Star Wars universe. Even Chewbacca himself gave one a thumbs-up!

Weathering goes a long way towards creating a convincing prop — it can turn a bundle of pipes and some foam blocks into a movie-ready WWII machine gun.

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Left: the traces of a flashy paper Christmas tree. Right: the finished tree on cardstock.

Flashy Paper Christmas Tree Does It With A 555

December 13, 2024 by Kristina Panos 11 Comments

‘Tis the season for holiday hacks, and [Ben Emmett] is here to remind us that we don’t necessarily need a fancy microcontroller in order to make flashy fun things happen.

Smoothing down the copper traces with a guitar pick.

Take this Christmas tree for example, which uses a 555 timer and a CB4017 decade counter in order to drive some blinking LEDs. The ICs are through-hole, making the circuit fairly accessible to new players, but there are a few SMD components that need soldering as well. (More on that later.)

Here, the 555 acts like a clock and drives a square wave. Using the clock as input, the decade counter toggles the output pins one after the other, driving the LEDs to blink in turn. Since there are only eight lights, there is a pause in the light-up pattern, but that could be fixed by wiring decade counter output #9 to the reset pin.

Although function was the main focus circuit-wise, [Ben] managed to lay the traces in the shape of a Christmas tree, which looks great. Having done a similar project in the past, he discovered that the craft cutting machine prefers thick traces and wider spaces between them. This is largely why [Ben] chose to use through-hole ICs.

After laying everything out in KiCad, [Ben] exported the copper layer image for use on the cutting machine. Once it was all cut out, he put it on transfer tape to weed out the extra copper, and get the traces onto cardstock, the final substrate.

This is such a fun project, and we love that the CR2032 that powers it also acts as the stand in its vertical holder. Hit up GitHub if you want to make one for yourself. Want something even more 3D? Check out this hollow tree we saw a few years ago.

Apple Newton Gets Rebuilt Battery Pack

December 13, 2024 by Bryan Cockfield 14 Comments

We all carry touch screen computers around in our pockets these days, but before the smartphone revolution, there was the personal digital assistant (PDA). While it wasn’t a commercial success, one of the first devices in this category was the Apple Newton. Today they’re sought after by collectors, although most of the ones surviving to this day need a bit of rework to the battery pack. Luckily, as [Robert’s Retro] shows, it’s possible to rebuild the pack with modern cells.

By modern standards, the most surprising thing about these battery packs is both that they’re removable and that they’re a standard size, matching that of AA batteries. The Newton battery pack uses four cells, so replacing them with modern rechargeable AA batteries should be pretty straightforward, provided they can be accessed. This isn’t as easy, though. In true Apple fashion the case is glued shut, and prying it apart can damage it badly enough so it won’t fit back in the tablet after repair is complete. The current solution is to cut a hatch into the top instead and then slowly work on replacing the cells while being careful to preserve the electronics inside.

[Robert’s Retro] also demonstrates how to spot weld these new AA batteries together to prepare them for their new home in the Newton case. With the two rows fastened together with nickel strips they can be quickly attached to the existing electrical leads in the battery pack, and from there it’s just a matter of snapping the batteries into the case and sliding it back into the tablet. If you’re looking for something a bit more modern, though, we’d recommend this Apple tablet-laptop combo, but it’s not particularly easy on the wallet.

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