It Turns Out, A PCB Makes A Nice Watch Dial

August 26, 2024 by 19 Comments

Printed circuit boards are typically only something you’d find in a digital watch. However, as [IndoorGeek] demonstrates, you can put them to wonderful use in a classical analog watch, too. They can make the perfect watch dial!

Here’s the thing. A printed circuit board is fundamentally some fiberglass coated in soldermask, some copper, maybe a layer of gold plating, and with some silk screen on top of that. As we’ve seen a million times, it’s possible to do all kinds of artistic things with PCBs; a watch dial seems almost obvious in retrospect!

[IndoorGeek] steps through using Altium Designer and AutoCAD to layout the watch face. The guide also covers the assembly of the watch face into an actual wrist watch, including the delicate placement of the movement and hands. They note that there are also opportunities to go further—such as introducing LEDs into the watch face given that it is a PCB, after all!

It’s a creative way to make a hardy and accurate watch face, and we’re surprised we haven’t seen more of this sort of thing before. That’s not to say we haven’t seen other kinds of watch hacks, though; for those, there have been many. Video after the break.

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Setup of a small lightbulb passing light through a thin film

Experimenting With Interference On Thin Layers

August 26, 2024 by No comments

[Stoppi] has taken on a fascinating project involving the interference of thin layers, a phenomenon often observed in everyday life but rarely explored in such depth. This project delves into the principles of interference, particularly focusing on how light waves interact with very thin films, like those seen in soap bubbles or oil slicks. The post is in German, but you can easily translate it using online tools.

Interference occurs when waves overlap, either reinforcing each other (constructive interference) or canceling each other out (destructive interference). In this project, [Stoppi] specifically examines how light behaves when passing through thin layers of air trapped between semi-transparent mirrors. When light waves reflect off these mirrors, the difference in path length leads to interference patterns that depend on the layer’s thickness and the wavelength of the light.

To visualize this, [Stoppi] used an interferometer made from semi-transparent mirrors and illuminated it with a bulb to ensure a continuous spectrum of light. By analyzing the transmitted light spectrum with a homemade spectrometer, he observed clear peaks corresponding to specific wavelengths that could pass through the interferometer. These experimental results align well with theoretical predictions, confirming the effectiveness of the setup.

If you like pretty patterns, soap bubbles are definitely good for several experiments. Don’t forget: pictures or it didn’t happen.

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Supercon 2024: Show Off Your Unique Display Tech

August 26, 2024 by 4 Comments

If there’s a constant in the world of electronics, it’s change. Advancements and breakthroughs mean that what was once state-of-the-art all too soon finds itself collecting dust. But there are exceptions. Perhaps because they’re so much more visible to us than other types of components, many styles of displays have managed to carve out their own niche and stick around. Even for the display types that we no longer see used in consumer hardware, their unique aesthetic qualities often live on in media, art, and design.

This year, to coincide with Hackaday Supercon, the folks at Supplyframe’s DesignLab want to pay tribute to display technology past and present with a special exhibit — and they need your help to make it possible. If you have a display you’d like to show off, fill out this form and tell them what you’ve got. Just be sure to do it by September 16th.

For the larger specimens, it would be ideal if you’re somewhat local to Southern California, but otherwise, they’re looking for submissions from all over the world. The exhibit will open on the first day of Supercon and run throughout November.

Don’t worry. They’re only looking to raid your parts bin temporarily. Any hardware sent in to be part of the exhibit will be considered on loan, and they’ll make sure it gets back to where it belongs by January 31st, 2025. The goal is to show the displays on and operational, so in most cases, that’s going to mean sending over a complete device. But if it’s possible to isolate the display itself and still demonstrate what it would look like in operation, sending along just the bare display is an option. Continue reading “Supercon 2024: Show Off Your Unique Display Tech” →

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Folding Typewriter

August 26, 2024 by 7 Comments

Have you built yourself a macro pad yet? They’re all sorts of programmable fun, whether you game, stream, or just plain work, and there are tons of ideas out there.

A DIY macro pad with key switches, dual linear pots, a rotary encoder, a screen, and a speaker.
Image by [CiferTech] via Hackaday.IO
But if you don’t want to re-invent the wheel, [CiferTech]’s MicroClick (or MacroClick — the jury is still out) might be just what you need to get started straight down the keyboard rabbit hole.

This baby runs on an ATmega32U4, which known for its Human Interface Device (HID) capabilities. [CiferTech] went with my own personal favorite, blue switches, but of course, the choice is yours.

There are not one but two linear potentiometers for volume, and these are integrated with WS2812 LEDs to show where you are, loudness-wise. For everything else, there’s an SSD1306 OLED display.

But that’s not all — there’s a secondary microcontroller, an ESP8266-07 module that in the current build serves as a packet monitor. There’s also a rotary encoder for navigating menus and such. Make it yours, and show us!

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Insides of a multimeter, improved with a custom backlight switch.

Backlight Switch For A Better Multimeter

August 26, 2024 by 28 Comments

Frustrated by his Aldi multimeter’s backlight turning off after just 15 seconds, [Steg Steg] took matters into his own hands. His solution? He added a manual toggle switch to control the backlight, allowing it to stay on as long as needed. He began by disassembling the multimeter—removing the outer bumper and a few screws—to access the backlight, labeled “BL.” He identified the voltage regulator outputting 2.8 V, desoldered the red wire, and extended it to install the switch.

On his first try, he successfully drilled a spot for the SPST switch. To fit the switch into the multimeter’s rubber bumper, he used a circular punch, although his second hole wasn’t as clean as the first. Despite this minor setback, the modification worked perfectly, giving him complete control over his multimeter’s backlight without the original 15-second timeout.

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Everything You Wanted To Know About Early Macintosh Floppies

August 26, 2024 by 30 Comments

Using a disk drive today is trivial. But back “in the day,” it was fairly complex both because the drives were simple and the CPUs were not powerful by today’s standards. [Thomas] has been working on a 68000 Mac emulator and found that low-level floppy information was scattered in different places. So he’s gathered it all for us in one place.

Low-level disk access has a lot of subtle details. For example, the Mac calibrates its speed control on boot. If your emulated drive just sets the correct speed and doesn’t respond to changes during calibration, the system will detect that as an error. Other details about spinning disks include the fact that inner tracks are shorter than outer track and may require denser recordings. Laying out sectors can also be tricky since you will lose performance if you, for example, read sector one and then miss sector two and have to wait for it to come back around. Disk sectors are often staggered for this reason.

Adding to the complexity is the controller — the IWM or Integrated Woz Machine — which has an odd scheme for memory mapping I/O. You should only access the odd bytes of the memory-mapped I/O. The details are all in the post.

In a way, we don’t miss these days, but in other ways, we do. It wasn’t that long ago that floppies were king. Now it is a race to preserve the data on them while you still can.

A Simple But Effective Receiving Loop Antenna

August 25, 2024 by 21 Comments

There’s a joke in the world of radio that all you need for a HF antenna is a piece of wet string, but the truth is that rudimentary antennas rarely perform well. Random pieces of wire may pull in some signal, but along with it comes a ton of unwanted interference and noise. It’s thus worth putting in the effort to make a better antenna, and if you’re not fortunate enough to have a lot of space, your best choice may be a magnetic loop. [Robert Hart] takes us through the design of a receive-only coaxial loop. It’s referred to as a Moebius loop because the conductor takes a “twist” path between the inner and outer halfway around.

The idea of a loop antenna is simple enough. It’s an inductor intended to respond to the magnetic portion of the wave rather than the electric part. They’re normally made of a single turn of wire in a loop of diameter well below half a wavelength, and, in their transmitting versions, they are often tuned to resonance by an air-spaced variable capacitor. Coaxial loops like this one provide enhanced resistance to electrical noise. He’s using some rather expensive Andrews coax for its rigidity, but the less well-heeled can use cheaper stuff without penalty. The result, when put on a frame of PVC pipe and a speaker stand, is an excellent portable receiving antenna, and if we’re being honest, something we might also consider in our own shack.

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