Digital Organizer Given Modern Upgrade

May 18, 2026 by No comments

Remember digital organizers? They were like the lower-spec version of a PDA that couldn’t really do much more than store a few phone numbers and calendar entries. [TundraLegendZ] recently grabbed such a device from 1995 and set about transforming it into something a little more capable.

The device in question is a Casio Business Organizer Scheduling System SF-5580. The original guts have been replaced , though, with the power of a Raspberry Pi Zero. The single-board computer is hooked up to a small color LCD screen with a resolution of 480 x 800, which is tucked neatly into the spot where the original display lived. There’s also a Raspberry Pi Pico on board, which is charged with interfacing all 82 keys of the original keyboard. Power is courtesy of a 6000 mAh battery which should last a good few hours on a single charge. Hearing the buzzer hacked is fun, too. It’s more mobile phone ringtone than outright chiptune, but we still enjoyed listening to the results. Screencaps of the software show just what this setup can do with better hardware and a nicer screen than 1995 could provide. Future work is planned to give the build more capabilities with a HackRF upgrade.

We’re not convinced anyone ever got much use out of these diminutive digital organizers, but a great many were sold in the 1990s.

Prolog Via Pokémon

May 18, 2026 by No comments

Like many people who read Hackaday, we are fairly fluent in a number of computer languages, but we have to admit it is easier to pick up languages that look like they group with things like Fortran. Sure, modern languages have all sorts of features, but the idea that you have a text file that executes in some order, variables, statements, and so on runs through most popular languages, but not all of them. Lisp and its variants are a different way of looking at things. And then there’s Prolog. [Alexander Petros] has an interesting way of explaining Prolog as a Pokémon game.

Prolog was “the next big thing” when AI meant expert systems. It is more of a specialized database where you define facts and rules that the computer can infer answers to queries. For example, if the facts say that Paul and Anna both have Mary as a parent, and a rule says that people with the same parent are siblings, then a query asking whether Paul and Anna are siblings will indicate that they are.

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Electroplating 3D Prints Without Requiring A Big Vat

May 18, 2026 by 3 Comments

Electroplating 3D prints is a good way to get a pretty nice coating on even a basic PLA part, but generally you’re expected to dunk the entire part into a big vat with electrolyte after coating it with the requisite conductive paint layer. This is great for small parts, like a ring you’d put on a finger, but gets rather silly when it’s a much larger part, such as the one in [Hendrik]’s recent video. Out of curiosity he tried to see whether rotating the part through a much smaller vat would still get you an even coating, or not.

Perhaps ironically this process required building a custom vat out of acrylic, as well as an entire rig to hold up the part and gently rotate it. This highlights the main disadvantage of this approach, in that unless you’re doing a small production run or otherwise get to re-use the rig a lot it’s a lot of extra effort.

That said, the rotation is controlled by an ESP32 and a stepper motor along with a requisite stepper driver, with the most exotic part being the whole custom PCB and enclosure, all of which can be used repeatedly. With all of that tested and confirmed working, the part to be plated was sanded, sprayed with conductive paint and hooked up to the rotating rig for an overnight run.

Following that the part’s new copper coating was polished before more layers of electroplating were applied to get the desired two different colors from different metals. Along the way no issues were found with this method of rotating electroplating, so if you regularly struggle with oversized parts to electroplate, this would seem to be a viable method.

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Voltmeter Clock Has The Time Dialled In

May 18, 2026 by 13 Comments

You could make a clock with three hands spinning about nested central shafts. If you did that, we probably wouldn’t publish it on Hackaday unless you really found a way to make it interesting. Make a clock out of voltmeters, however, and that usually catches our eye. [lcamtuf] has done just that.

The heart of the build is an AVR128DB28 microcontroller, an 8-bit microcontroller that is still currently in production. It runs at 8MHz, and drives a series of three Baomain 65C5 voltmeters to display hours, minutes, and seconds. Each has a custom printed face with the correct number of 13 or 61 divisions as needed. The voltmeters are driven by a continuous stream of 1-bit pulses with a software-controlled duty cycle determining exactly how far the needle moves. Yes, it’s using simple pulse width modulation, coded by hand by [lcamtuf] to do the job. All the components are wrapped up in a beautiful wooden case, with delicately kerf-bent panels to create the attractive curved lines.

We’ve featured similar builds before, too. As it turns out, hackers just really love clocks and old-school dials. Video after the break, which is worth watching for the rollover behaviour alone.

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A 3D-printed telescope with an infrared laser on the side is pointed out the window of a building at night.

Long-Range Night Vision With An Infrared Laser

May 18, 2026 by 8 Comments

Most consumer-grade night vision devices are basically a standard camera without the usual filter to block near infrared (NIR) light, which are then paired with a NIR light source that’s not visible to the human eye. Unlike the passive night vision provided by an image intensifier tube, these can’t resolve objects beyond the beam of their illumination source. On the other hand, if, as [Project 326] did, you use an infrared laser to illuminate the scene, you can still get a very long range out of these devices.

[Project 326]’s device consists of a previously-built reflecting telescope focusing a distant scene in to a webcam with the infrared filter removed, with the infrared laser illuminating the scene. Finding a suitable laser took some effort: the first option, a secondhand fiber-coupled industrial laser, was accidentally over-volted and destroyed during testing. The second had a fiber output which proved extremely hard to terminate, and a third laser couldn’t be collimated correctly. The final laser was a Vertical-Cavity Surface-Emitting Laser (VSEL) diode array element driven at about two Watts and collimated by a small lens.

This illumination setup is safe at a long range, but only at a long range. The laser was strong enough to burn cardboard at close range, but out at about 500 meters, the beam had spread until it was less than a hundredth of the standard safety limit. To make sure that nothing else would get in the way of the beam, it was shone down from the top of a tall building. Testing with a power meter also showed that at a long range, the beam was weaker than expected. It turned out that the wavelength used (940 nm) is attenuated by water vapor, to the point that up to 70% of the beam’s strength was lost before reaching the target. Despite this, and despite a rather linear beam profile, a somewhat dark image was still visible at 650 meters.

If you’re looking for a somewhat more versatile long-range night vision device, check out one based on an image intensifier. Another approach is to use a very high-sensitivity camera.

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How To Make Steel That Breathes

May 18, 2026 by 7 Comments

There are plenty of porous materials out there that we’re all readily familiar with. Fabrics and wood are great examples, allowing liquids or gases to pass through to a certain degree—a property which is useful or problematic depending on the application.

Metals, however, are not something we would readily consider to be porous. They are solid, unyielding, and impermeable. However, with the right techniques, it is possible to produce so-called “breathable” steel, which has particularly interesting applications in the molding industry.

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Small Engine Gets DIY EFI Upgrade

May 18, 2026 by 26 Comments

Small internal combustion engines usually keep things simple, relying on carburetors to handle metering the correct amount of fuel and air. Recently, [Carlos Takeshita] decided his small engine could use an upgrade in the form of electronic fuel injection (EFI).

The build began with a Predator 212, a popular gasoline engine from Harbor Freight. [Carlos] set about kitting it out with a missing tooth trigger wheel to measure the crankshaft position with a hall effect sensor. The engine also scored a custom-built aluminium fuel cell, complete with a high-pressure fuel pump and regulator suitable for driving the solitary fuel injector installed in the custom intake manifold. A Teensy 4.0 is charged with monitoring a manifold air pressure (MAP) sensor and the crank position, and choosing when and how long to fire the injector to dose the engine with the correct amount of fuel. Files are on GitHub for those eager to dive deeper.

It can be quite a job to convert an engine to run with electronic fuel injection, but you’re certain to learn a lot during the install and tuning process. We’ve featured similar builds many times over the years.

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