TechyMagThings

Fidget toys are everywhere these days. A particularly popular type simply puts some keyboard switches on a plate to provide a certain type of clicky satisfaction. [wjddnjsdnd] took that concept a step further, building a keychain-sized fidget toy that actually has games on it.

The build is based around six key switches in a 2 x 3 array. The key switches are notable in this case for being magnetic shaft keys. Rather than using a mechanical switch to indicate a keypress, the keycap instead merely moves a magnet which triggers a signal in a hall effect sensor beneath the key. In this case, the build uses A3144 hall effect sensors, which are read by the Arduino Nano running the show. The Nano is also hooked up to a small SSD1306 OLED display over I2c, which it uses for displaying the game state. There’s also a TP4056 module to handle charging the attached 380 mAh lithium-ion battery which powers the pocket-sized device.

The Arduino Nano is not a powerful platform for gaming, but it can handle the basics. The Gamebox Clicker, as it’s called, features a Pong clone, a stairs game, and a recreation of Snake. Think early mobile phone games, and you’d be on the money.

It’s an interesting build, and one that would be a great way to get used to using magnetic key switches as well as small embedded displays. We’ve seen Arduino boards turned into microconsoles many times before, too. If you’d like to sound off about magnetic vs. mechanical key switches, jump into the comments, or otherwise let us know about your best electronic fidget projects on the tipsline. Happy hacking.

This week, Hackaday’s Elliot Williams and Kristina Panos met up over coffee to bring you the latest news, mystery sound results show, and of course, a big bunch of hacks from the previous seven days or so.

We found no news to speak of, except that Kristina has ditched Windows after roughly 38 years. What is she running now? What does she miss about Windows? Tune in to find out.

On What’s That Sound, Kristina thought it was a jackhammer, but [Statistically Unlikely] knew it was ground-tamper thingy, and won a Hackaday Podcast t-shirt! Congratulations!

After that, it’s on to the hacks and such, beginning with 3D printing on the nano scale, and a couple of typewriter-based hacks.  Then we take a look at the beauty of the math behind graph theory, especially when it comes to circuit sculptures and neckties.

We also talk display hacking, macro pads with haptic feedback knobs, and writing code in Welsh. Finally, we discuss the Virtual Boy, and ponder whether vibe coding is killing open source.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in DRM-free MP3 and savor at your leisure.

Episode 356 Show Notes:

News:

• No news is good news, except that Kristina ditched Windows after ~38 years!

What’s that Sound?

• Congrats to [Statistically Unlikely] who knew this was an Earth-stomping machine!

Interesting Hacks of the Week:

• The Latest From RepRapMicron – Nail Gel, First Objects, And More
• Lego Typewriter Writes Plastic Letters
• Comprehensive Power Management For The Raspberry Pi
• Crouching Typewriter, Hidden PC
• The Graph Theory Of Circuit Sculptures
  • The 85 Ways to Tie a Tie
  • The Mathematics of Tie Knots
• DIY Macropad Rocks A Haptic Feedback Wheel
  • Simplifying The SmartKnob

Quick Hacks:

• Elliot’s Picks:
  • 5K IMac Turned Into 5K Display
  • CPU Scheduler Divines The Will Of The Heavens
  • An Event Badge Re-Imagined As A Cyberdeck
  • Ysgrifennu Côd Yn Gymraeg (Writing Code In Welsh)
• Kristina’s Picks:
  • Ordering Pizza On Your Sega Dreamcast Is Very Clunky Indeed
  • Need A Curved Plastic Mesh? Print Flat, Curve Later
  • Running DOOM And Super Mario 64 Inside A PDF File

Can’t-Miss Articles:

• After 30 Years, Virtual Boy Gets Its Chance To Shine
• How Vibe Coding Is Killing Open Source

[Prof MAD] runs us through The Hidden Power of Inductors — Why Coils Resist Change.

The less often used of the passive components, the humble and mysterious inductor is the subject of this video. The essence of inductance is a conductor’s tendency to resist changes in current. When the current is steady it is invisible, but when current changes an inductor pushes back. The good old waterwheel analogy is given to explain what an inductor’s effect is like.

There are three things to notice about the effect of an inductor: increases in current are delayed, decreases in current are delayed, and when there is no change in current there is no noticeable effect. The inductor doesn’t resist current flow, but it does resist changes in current flow. This resistive effect only occurs when current is changing, and it is known as “inductive reactance”.

After explaining an inductor’s behavior the video digs into how a typical inductor coil actually achieves this. The basic idea is that the inductor stores energy in a magnetic field, and it takes some time to charge up or discharge this field, accounting for the delay in current that is seen.

There’s a warning about high voltages which can be seen when power to an inductor is suddenly cut off. Typically a circuit will include snubber circuits or flyback diodes to help manage such effects which can otherwise damage components or lead to electric shock.

[Prof MAD] spends the rest of the video with some math that explains how voltage across an inductor is proportional to the rate of change of current over time (the first derivative of current against time). The inductance can then be defined as a constant of proportionality (L). This is the voltage that appears across a coil when current changes by 1 ampere per second, opposing the change. The unit is the volt-second-per-ampere (VsA^-1) which is known as the Henry, named in honor of the American physicist Joseph Henry.

Inductance can sometimes be put to good use in circuits, but just as often it is unwanted parasitic induction whose effects need to be mitigated, for more info see: Inductance In PCB Layout: The Good, The Bad, And The Fugly.

[GizmoThrill] shows off a design for an absolutely gorgeous, high-fidelity replica of the main character’s helmet from the video game Satisfactory. But the best part is the technique used to create the visor: just design around a cheap set of full-face “sunglasses” to completely avoid having to mold your own custom faceplate.

One of the most challenging parts of any custom helmet build is how to make a high-quality visor or faceplate. Most folks heat up a sheet of plastic and form it carefully around a mold, but [GizmoThrill] approached the problem from the other direction. After spotting a full-face sun visor online, they decided to design the helmet around the readily-accessible visor instead of the other way around.

The first thing to do with the visor is cover it with painter’s tape and 3D scan it. Once that’s done, the 3D model of the visor allows the rest of the helmet to be designed around it. In the case of the Satisfactory helmet, the design of the visor is a perfect match for the game’s helmet, but one could easily be designing their own custom headgear with this technique.

With the helmet 3D printed, [GizmoThrill] heads to the bandsaw to cut away any excess from the visor, and secure it in place. That’s all there is to it! Sure, you don’t have full control over the visor’s actual shape, but it sure beats the tons and tons of sanding involved otherwise.

There’s a video tour of the whole process that shows off a number of other design features we really like. For example, metal mesh in the cheek areas and in front of the mouth means a fan can circulate air easily, so the one doesn’t fog up the inside of the visor with one’s very first breath. The mesh itself is concealed with some greebles mounted on top. You can see all those details up close in the video, embedded just below.

The helmet design is thanks to [Punished Props] and we’ve seen their work before. This trick for turning affordable and somewhat gimmicky sunglasses into something truly time-saving is definitely worth keeping in mind.

When you think of a toy tractor, what probably comes to mind is something with fairly simple lines, maybe the iconic yellow and green, big rear tires, small front ones. Well, that’s exactly what [James] built, with simple, clean lines and a sturdy build that will hold up to driving around off-road in the garden. This Tractor is a great build, combining CAD, metal and wood work, some 3D printing, and electronics.

Starting at the power plant for the build, [James] went with a 350W DC motor powered by a 36V Li-ion battery from an e-bike. The motor turns a solid rear axle he made on a mini-lathe, connected to a set of riding lawn mower wheels. The mini-lathe spindle bore was too small to accommodate the shaft, and the lathe was not long enough to use the tailstock, so [James] had to get creative, using a vice and a piece of wood to make a stand–in tailstock, allowing him to turn this custom rear axle. The signature smoothly curved bonnet was made possible with plywood and body filler, rather than the sheet metal found on full-sized tractors. In fact, most of the build’s frame used plywood, giving it plenty of strength and, once painted, helping give it the appearance of a toy pulled out of a toybox.

This build had a bit of many domains in it, and all combined into a fantastic final result that no doubt will bring a smile to any face that gets to take the Tractor for a ride. Thanks [James] for documenting your build process, the hacks needed to pull off the tough bits along the way in making this fun toy. If you found this fun, be sure to check out another tractor related project.

Macropads can be as simple as a few buttons hooked up to a microcontroller to do the USB HID dance and talk to a PC. However, you can go a lot further, too. [CNCDan] demonstrates this well with his sleek macropad build, which throws haptic feedback into the mix.

The build features six programmable macro buttons, which are situated either on side of a 128×64 OLED display. This setup allows the OLED screen to show icons that explain the functionality of each button. There’s also a nice large rotary knob, surrounded by 20 addressable WS2811 LEDs for visual feedback. Underneath the knob lives an an encoder, as well as a brushless motor typically used in gimbal builds, which is driven by a TMC6300 motor driver board. Everything is laced up to a Waveshare RP2040 Plus devboard which runs the show. It’s responsible for controlling the motors, reading the knob and switches, and speaking USB to the PC that it’s plugged into.

It’s a compact device that nonetheless should prove to be a good productivity booster on the bench. We’ve featured [CNCDan’s] work before, too, such as this nifty DIY VR headset.

While Apple weren’t the first to invent high-DPI displays or to put them into consumer electronics, they did popularize them fairly effectively with the Retina displays in the early 2010s and made a huge number of them in the following years. The computers they’re attached to are getting up there in age, though, and although these displays are still functional it isn’t quite as straightforward to use them outside of their Apple-approved use. [David] demonstrates one way of getting this done by turning a 5k iMac into an external monitor.

The first attempt at getting a usable monitor from the old iMac was something called a Luna Display, but this didn’t have a satisfying latency. Instead, [David] turned to replacing the LCD driver board with a model called the R1811. This one had a number of problems including uneven backlighting, so he tried a second, less expensive board called the T18. This one only has 8-bit color instead of the 10-bit supported by the R1811 but [David] couldn’t personally tell the difference, and since it solved the other issues with the R1811 he went with this one. After mounting the new driver board and routing all of the wires, he also replaced the webcam with an external Logitech model and upgraded the speakers as well.

Even when counting the costs for both driver boards, the bill for this conversion comes in well under the cost of a new monitor of comparable quality from Apple, a company less concerned about innovation these days than overcharging their (admittedly willing) customers. For just a bit of effort, though, these older iMacs and other similar Apple machines with 5k displays can be repurposed to something relatively modern and still usable. Others have done similar projects and funded the upgrades by selling off the old parts.