Misc Hacks

4124 Articles

Creating A Numbers Station Of Your Very Own

March 17, 2024 by 13 Comments

Numbers stations are a weird phenomenon where odd voices read out long strings of numbers or random codewords to the confusion of the vast majority of the listening audience. If you’ve ever wanted to build one of your own, you could follow the example of [AudioWanderer].

NumberMumble, as it’s called, is a numbers station emulator. It doesn’t signal spy networks or reveal national secrets. Instead, it randomly plays audio samples using an Arduino, including characteristic bursts of white noise that make it sound more authentic. It relies on the Mozzi library to help with audio tasks, including generating white noise and playing back samples. It’s also kitted out with a filter knob for varying the tone. Audio output is via PWM.

If you want to confuse your neighbours with oddball audio, put this thing on a radio transmitter and get broadcasting. But don’t, because that’s illegal without the proper licenses or — you know — if you happen to be a real spy. Video after the break.

Continue reading “Creating A Numbers Station Of Your Very Own” →

Cheap DIY Microscope Lamp Makes Tiny Macro Shots Look Great

March 16, 2024 by 9 Comments

For optical microscopes, light is everything. If you don’t have a good amount of light passing through or bouncing off your sample, you’ve got nothing for your eyeballs or a camera to pick up. To aid in this regard, [Halogenek] whipped up a nifty microscope lamp with some LEDs.

The build uses a neat arch-shaped PCB with a hole in the middle for the microscope’s optics to pass through. Surrounding this are the LEDs, which provide a circle of light focused on the sample, akin to the ring lights so favored by today’s online influencers. The LEDs are powered via USB C, so the lamp can be run off of any garden-variety phone charger you might have lying around.

[Halogenek] reports that the lamp has proven useful for extreme macro shots of PCBs. It’s an easy build to replicate or redesign your own way if you’re doing similar work.

Microscopes are super useful, and there are all kinds of hacks you can do to make them perform better in your quest for science. Meanwhile, if you’ve been jazzing up your own lab hardware, let us know—we’d love to hear about it!

The Perils Of Return Path Gaps

March 15, 2024 by 9 Comments

The radio frequency world is full of mysteries, some of which seem to take a lifetime to master. And even then, it seems like there’s always something more to learn, and some new subtlety that can turn a good design on paper into a nightmare of unwanted interference and unexpected consequences in the real world.

As [Ken Wyatt] aptly demonstrates in the video below, where you put gaps in return paths on a PCB is one way to really screw things up. His demo system is simple: a pair of insulated wires running from the center pins on BNC jacks and running along the surface of a piece of copper-clad board to simulate a PCB trace. The end of each wire is connected to the board’s ground plane through a 50 ohm resistor, with one wire running over a narrow slot cut into the board. A harmonics-rich signal is fed into each trace while an H-field EMC probe connected to a spectrum analyzer is run along the length of the trace.

With the trace running over the solid ground plane, the harmonics are plentiful, as expected, but they fall off very quickly away from the trace. But over on the trace with the gapped return trace it’s a far different story. The harmonics are still there, but they’re about 5 dBmV higher in the vicinity of the gap. [Ken] also uses the probe to show just how far from the signal trace the return path extends to get around the gap. And even worse, the gap makes it so that harmonics are detectable on the unpowered trace. He also uses a current probe to show how common-mode current will radiate from a long conductor attached to the backplane, and that it’s about 20 dB higher with the gapped trace.

Hats off to [Ken] for this simple explanation and vivid reminder to watch return paths on clock traces and other high-frequency signals. Need an EMC probe to check your work? A bit of rigid coax and an SDR are all you need.  Continue reading “The Perils Of Return Path Gaps” →

Building A Hydraulic Loader For A Lawn Tractor

March 14, 2024 by 10 Comments

Lawn tractors are a great way to mow a large yard or small paddock. They save you the effort of pushing a mower around and they’re fun to drive, to boot. However, they can be even more fun with the addition of some extra hardware. The hydraulic loader build from [Workshop from Scratch] demonstrates exactly how.

The build is based around a John Deere LX188 lawn tractor, which runs a 17 horsepower Kawasaki engine and features a hydrostatic transmission. It’s a perfectly fine way to mow a lawn. In this case, though, it’s given new abilities with the addition of a real working loader. It’s fabricated from raw steel from the arms right down to the bucket. It’s all run from a hydraulic pump, which is mounted to the engine via an electromagnetic clutch. The clutch can be engaged when it’s desired to use the hydraulics to actuate the loader.

As you might expect, the humble lawn tractor isn’t built for this kind of work. Thus, to support the extra equipment, the mower was also given some frame reinforcements and a wider track for stability.

If you’re trying to give your neighbours mower envy, this is how you do it. Or, you could go another route entirely. Video after the break.
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A 555-Shaped Discrete Component 555

March 11, 2024 by 2 Comments

While the “should have used a 555” meme is strong around these parts, we absolutely agree with [Kelvin Brammer]’s decision to make this 555-shaped plug-in replacement for the 555 timer chip using discrete parts, rather than just a boring old chip.

As [Kelvin] relates, this project started a while back as an attempt to both learn EDA and teach students about the inner workings of the venerable timer chip. The result was a 555-equivalent circuit on a through-hole PCB, with the components nicely laid out into the IC’s functional blocks. As a bonus, the PCB was attached to an 8-pin header which could be plugged right in as a direct replacement for the chip.

Fast forward a few years, and [Kelvin] needed to learn yet another EDA package; what better way than to repeat the 555 project? It was also a good time to step into SMD design, as well as add a little zazzle. While the updated circuit isn’t as illustrative of the internal arrangement of the 555, the visual celebration of the “triple nickel” is more than worth it. And, just like the earlier version, this one has a header so you can just plug and chug — with style.

Want to know how the 555 came to be? We’ve covered that. You can also look at some basic 555 circuits to put your 555-shaped 555 to work. We’ve even seen a vacuum tube 555 if that’s more your thing.

Stacking Solar Cells Is A Neat Trick To Maximise Efficiency

March 7, 2024 by 51 Comments

Solar power is already cheap and effective, and it’s taking on a larger role in supplying energy needs all over the world. The thing about humanity, though, is that we always want more! Too much, you say? It’s never enough!

The problem is that the sun only outputs so much energy per unit of area on Earth, and solar cells can only be so efficient thanks to some fundamental physical limits. However, there’s a way to get around that—with the magic of tandem solar cells!

Continue reading “Stacking Solar Cells Is A Neat Trick To Maximise Efficiency” →

Large Language Model Can Help You Develop For The Amiga

March 5, 2024 by 13 Comments

Developing for the Amiga used to involve reading dense programming manuals and trial and error. In contrast, developing these days can be as simple as barking orders at ChatGPT to spit you out some Python code. However, that technique doesn’t work so well for Amiga languages, as ChatGPT hasn’t read much about the now-ancient platform. However, as covered by AmigaNews, there is now a ChatGPT model trained specifically on Amiga development. Enter Amiga Guru.

The work of [Cameron Armstrong], Amiga Guru was built after his early experiments with ChatGPT spat out non-functional gibberish when Amiga-compatible code was requested. The model has been trained on a corpus of official Amiga programming manuals, third-party books, and even the documentation for AmigaOS 3.2 and 4.1.

Using the model yourself requires a subscription to ChatGPT Plus, which prevents this writer from testing it directly. However, it makes sense that having been directly trained on Amiga manuals, it would be more capable at answering Amiga programming queries than conventional ChatGPT 4.

It’s easy to see the value of such a system. Learning to program for older platforms can be hard, with less resources available for new learners. Having an AI to help could be useful for some eager to develop for the 68K-based machine.

If you’d like to try Amiga Guru, you can access it via this link. Be sure to let us know how you go, and whether you think it has any value for speeding up your own Amiga development. Otherwise, if you’ve been doing anything else nifty with the platform that Commodore bought and paid for, don’t hesitate to let us know!

[Thanks to Stephen Waters for the tip!]