A Treasure Trove In An English Field

This is being written in a tent in a field in Herefordshire, one of the English counties that borders Wales. It’s the site of Electromagnetic Field, this year’s large European hacker camp, and outside my tent the sky is lit by a laser light show to the sound of electronic music. I’m home.

One of the many fun parts of EMF is its swap table. A gazebo to which you can bring your junk, and from which you can take away other people’s junk. It’s an irresistible destination which turns a casual walk into half an hour pawing through the mess in search of treasure, and along the way it provides an interesting insight into technological progress. What is considered junk in 2024?

Something for everyone

As always, the items on offer range from universal treasures of the I-can’t-believe-they-put that-there variety, through this-is-treasure-to-someone-I’m-sure items, to absolute junk. Some things pass around the camp like legends; I wasn’t there when someone dropped off a box of LED panels for example, but I’ve heard the story relayed in hushed tones several times since, and even seen some of the precious haul. A friend snagged a still-current AMD processor and some Noctua server fans as another example, and I’m told that amazingly someone deposited a Playstation 5. But these are the exceptions, in most cases the junk is either very specific to something, or much more mundane. I saw someone snag an audio effects unit that may or may not work, and there are PC expansion cards and outdated memory modules aplenty.

Finally, there is the absolute junk, which some might even call e-waste but I’ll be a little more charitable about. Mains cables, VGA cables, and outdated computer books. Need to learn about some 1990s web technology? We’ve got you covered. Continue reading “A Treasure Trove In An English Field”

An example of the case generated for a simple PCB, being shown in the OpenSCAD viewer

Turbocase Generates A PCB Shell For You

Our PCBs greatly benefit from cases – what’s with all the pins that can be accidentally shorted, connectors that stick out of the outline, and cables pulling the board into different directions. Designing a case for your PCB might feel like a fair bit of effort – but it likely isn’t, thanks to projects like turbocase from [Martijn Braam].

This script generates simple and elegant OpenSCAD cases for your KiCad PCBs – you only need to draw a few extra lines in the PCB Editor, that’s it. It makes connector openings, too – add a “Height” property to your connector footprints to have them be handled automatically. Oh, and there’s a few quality-of-life features – if your project has mounting holes, the script will add threaded-insert-friendly standoffs to the case; yet another argument for adding mounting holes to your boards, in case you needed more.

Installing the script is a single line, running it is merely another, and that will cover an overwhelming majority of boards out there; the code is all open too, of course. Want some more customization? Here’s some general project enclosure tutorials for OpenSCAD, and a KiCad-friendly StepUp tutorial. Oh, and of course, there’s many more ways to enclose PCBs – our own [Bob Baddeley] has written a guide to project enclosures that you are bound to learn new things from.

We thank [adistuder] for sharing this with us!

Using The Moiré Effect For Unique Clock Face

If you’ve ever seen artifacts on a digital picture of a computer monitor, or noticed an unsettling shifting pattern on a TV displaying someone’s clothes which have stripes, you’ve seen what’s called a Moiré pattern where slight differences in striping of two layers create an emergent pattern. They’re not always minor annoyances though; in fact they can be put to use in all kinds of areas from art to anti-counterfeiting measures. [Moritz] decided to put a few together to build one of the more unique clock displays we’ve seen.

The clock itself is made of four separate Moiré patterns. The first displays the hours with a stretching pattern, the second and third display the minutes with a circular pattern, and the seconds are displayed with a a spiral type. The “hands” for the clock are 3D printed with being driven by separate stepper motors with hall effect sensors for calibration so that the precise orientation of the patterns can be made. A pair of Arduinos control the clock with the high-accuracy DS3231 module keeping track of time, and [Moritz] built a light box to house the electronics and provide diffuse illumination to the display.

Moiré patterns can be used for a number of other interesting use cases we’ve seen throughout the years as well. A while back we saw one that helps ships navigate without active animations or moving parts and on a much smaller scale they can also be used for extremely precise calipers.

Continue reading “Using The Moiré Effect For Unique Clock Face”