On the left side of the image, three lit candles are positioned next to each other, so that the flames merge. On the right side, an oscilloscope screen is shown displaying an oscillating waveform.

2025 One Hertz Challenge: A Flaming Oscillator And A New Take On The Candle Clock

August 17, 2025 by 6 Comments

Candle clocks were once an easy way to build a clock without using complex mechanical devices: just observe how quickly a thin candle burns down, mark an identical candle with periodic gradations, and you had a simple timer. These were the first candle-based timekeeping devices, but as [Tim]’s flicker-based oscillator demonstrates, they’re certainly not the only way to keep time with a flame.

Generally speaking, modern candles minimize flickering by using a wick that’s designed to balance the amount of wax and air drawn into the flame. However, when several candles are brought close together, their flames begin to interfere with each other, causing them to flicker in synchrony. The frequency of flickering is a function of gravity and flame diameter alone, so a bundle of three candles will flicker at a fairly constant frequency; in [Tim]’s case, it was about 9.9 Hz.

To sense this oscillation, [Tim] originally used a phototransistor to detect the flame’s light, but he wanted an even simpler solution. He positioned a wire just above the flame, so that as it flickered it would periodically contact the wire. A flame has a different dielectric constant than air does, so the capacitance between this and another wire wrapped around the bundle of candles fluctuates with the flame. To sense this, he used a CH32V003 microcontroller, which reads capacitance, performs some signal processing to get a clean signal, counts oscillations, and uses this time signal to blink an LED once a second. The final result is unusually mesmerizing for a blinking LED.

In something of the reverse of this project, we’ve also seen an oscillator used for an (artificial) candle. There’s also a surprising amount of science that can be learned by studying candles.

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Recto: In Case Programming Isn’t Hard Enough

August 17, 2025 by 20 Comments

There’s long been a push to stop writing code as a sequence of lines and go to something graphical, which has been very successful in some areas and less so in others. But even when you use something graphical like Scratch, it is really standing in for lines of code? Many graphical environments are really just interface builders, and you still write traditional code underneath. [Masato Hagiwara] asks the question: Can you write code that is actually a 2D graphic? Where the graphical layout isn’t a cover for code, but is the code itself? His answer is Recto.

Whereas a C program, for example, has a syntactical structure of lines, a Recto program has rectangles. Rectangles can contain data, and their structure naturally mimics the kinds of structures we usually use: columns, rows, matrices, and so on. Rectangles can also contain… wait for it… other rectangles. Special rectangles act as dictionaries or sets.

We thought this sort of reminded us of Lisp, and, in fact, [Hagiwara] makes that clear later in the post. The real problem is how do you…write? draw?… this kind of code? At first, he laid it out in a spreadsheet before compilation. Now he’s built an editor for it, and you can try it in your browser. There’s also a limited-feature compiler that can handle simple programs.

[Hagiwara] goes on to show how this representation would work for natural human languages, too. Honestly, we have enough trouble with English and the few other human languages we struggle with, but it is interesting to contemplate.

If you like strange languages, there’s Piet. Not that either of these is the weirdest we’ve ever seen.

Sony PSP, Evan-Amos, Public Domain.

Llama Habitat Continues To Expand, Now Includes The PSP

August 17, 2025 by 14 Comments

Organic Llamas have a rather restricted range, in nature: the Andes Mountains, and that’s it. Humans weren’t content to let the fluffy, friend-shaped creatures stay in their natural habitat, however, and they can now be found on every continent except Antarctica. The Llama2 Large Language Model is like that: while it may have started on a GPU somewhere, thanks to enterprising hackers like [Caio Madeira], who has ported Llama2 to the PlayStation Portable (PSP), the fluffiest LLM can be found just about anywhere.

The AI, in all its glory, dooming yet another system.

Ultimately this project has its roots in Llama2.c by [karpathy], a project we’ve seen used on Pentium II under Windows 98, DOS machines running 486 processors, and even the venerable Commodore 64, of all impossible things. Now, it’s the PSP’s turn. This implementation uses the same 260K tinystories model as the C64 port, upon which it is based. Of course the PSP’s RAM has room for a much larger model, but [Ciao] apparently prefers to run the tiny model faster on this less-ancient gaming hardware.

Its getting to the point that it’s harder to find systems that won’t run LLMs than those that do. Given that Llama2 seems to be the new DOOM, it’s probably only a matter of time before their virtual fur is all over all our old equipment. Fortunately for allergy sufferers, virtual fur cannot trigger a histamine response.

If you know of another system getting LLMs (Alpaca-adjacent or otherwise), send in a tip.

It’s A Pi, But It’s Not Quite A Raspberry Pi

August 17, 2025 by 17 Comments

When is a Raspberry Pi not a Raspberry Pi? Perhaps when it’s a Pi Pico-shaped board with an RP3A0 SoC from a Raspberry Pi Zero 2, made by [jonny12375].

Back in the early days of the Raspberry Pi, there was a offering from the Korean manufacturer Odroid, which wasn’t merely a similar machine with a different SoC, but a full clone in a smaller form factor featuring the same BCM2385 chip as the original. It was electrically and software-wise identically to the real thing, which we suspect didn’t go down very well with the Pi folks in Cambridge. The supply of Broadcom chips dried up, and ever since then the only way to get a real Pi has been from the official source. That’s not quite the end of the unofficial Pi story though, because a few hardy experimenters have made Pi clones like this one using chips desoldered from the real thing.

It’s the fruit of a reverse-engineering project to find the chip’s pinout, and it’s a proof of concept board rather than the intended final target of the work. The process involved painstakingly sanding down each layer of a Zero 2 board to reveal the traces and vias. The current board has a few quirks but it boots, making this an impressive piece of work on all counts. We’re looking forward to seeing whatever the final project will be.

If you’re hungry for more Pi-derived goodness, we’ve also seen one using the part form a Pi 3.

Commodore Is Back Selling New C64s, But Should You Buy Them?

August 17, 2025 by 107 Comments

It’s hard to argue with nostalgia, but you can toss a bucket of cold facts over it. In the case of the recent rescuing of the Commodore brand from the clutches of relabeling of generic electronics by [Perifractic] of Retro Recipes, we got [The Retro Shack] doing the proverbial bucket dumping in a new video. Basically the question is whether the fresh Commodore 64 offerings by the new-and-improved Commodore are what you really want, or need.

The thing is that over the decades many people have created all the bits that you need to build your own classical C64, or even buy one off-the-shelf, with people like [bwack] having reverse-engineered the various C64 mainboards. These can be populated with drop-in replacements for chips like the SID, VIC-II, CIAs and others that are readily available, along with replica cases and keyboards. If you crave something less bulky and complex, you can run a bare metal C64 emulator like BMC64 on a Raspberry Pi, or just run the VICE emulator on your platform of choice. There’re also options like the full-sized TheC64 and Ultimate 64 Elite II systems that you can buy ready to go.

Basically, there is a whole gamut of ways to get some part of the C64 experience, ranging from emulator-only to a full hardware DIY or pre-assembled format. Each of which come with their own price tag, starting at $0 for running VICE on your existing system. With so much choice we can only hope that the renewed Commodore company will become something more than Yet Another C64 Experience.

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Meccano model of a Brennan's monorail

A Second Chance For The Single Wheel Monorail?

August 16, 2025 by 27 Comments

Lately, this peculiar little single wheel monorail came to our attention. Built by [extraglide1976], all from Meccano. His build started with modest tests: one gyro obviously flopped. Two gyros geared together ran slightly better. But when he adds active gimbal control, things suddenly come to life – the model shudders, catches itself, and carries on. The final green-roofed locomotive, with LEDs signalling ‘system go’, trundles smoothly along a single rail on [extraglide1976]’s deck.

To be fair, it houses a lot of mechanics and engineering which we don’t find in the monorails of today. We do have quite a few monorails in our world, but none of them balance on a single wheel like this one. So, where did this invention derail?

Outside of theme parks, Japan is one of the few countries where monorails are still used as serious urban transport: though Germany’s century-old Wuppertal Schwebebahn, the lesser-known C-Bahn, China’s sprawling Chongqing and Shanghai systems, Malaysia’s Kuala Lumpur line, Brazil’s São Paulo network, the US links in Seattle and Las Vegas, and India’s Mumbai Monorail prove the idea has quietly taken root elsewhere.

The thing you’ll see in nearly all these monorails is how the carriages are designed to clamp onto the tracks. This is of course the most safe option, but it loses out on speed to the ones that sit on top of the tracks, balancing on one wheel. Such a train was actually invented, in 1910, by Louis Brennan. His original monorail promised faster, cheaper transport, even using existing rails. The carriages leaned into turns like a motorbike, without any intervention from the driver. Two counter-rotating gyroscopes kept the carriage upright, cancelling precession forces like a mechanical Jedi trick.

Back then, it failed commercially, but today? With cheap sensors, brushless motors, and microcontrollers, and intelligent software, why  not let it make a comeback? It could carry freight through narrow urban tunnels. With high-speed single-rail pods?

Investors killed Brennan’s idea, but we live in a different time now. You could start out with a gimmicky ‘snacks and beer’ highline from your fridge to your garage. Share your take on it in the comments!

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From Smartphone To A Home Server

August 16, 2025 by 27 Comments

Some people like their homelabs to be as big and fancy as possible, with racks of new or surplus server hardware sucking down power. [Hardware Haven] evidently has the opposite idea, given he just made a video about making the cheapest, smallest server possible: an Android phone.

Sure, it’s not going to be streaming terabytes of data at multiple gigabytes per second, but that’s not everyone’s use case. Don’t forget, flagship phones had multiple cores and gigabytes of RAM a decade ago, so even an old and busted smartphone has more than enough power for something like Home Assistant, which is what gets installed in this video.

After considering loading termux and rooting his device for Docker-on-Android, he opted for postmarketOS, the premiere Linux for old smartphones. That’s not because the Linux environment you get with termux wouldn’t work; it’s just that he wanted something native. To that end, he bought a somewhat worse-for-wear Xiaomi Mi A1 from eBay to get hardware Alpine-based postmarket could use.

Software wise, it was just a matter of following instructions and reading manuals — Linux is Linux, after all. The firewall proved to be his main challenge, though trying to branch out from Home Assistant to run Minecraft Server did run into Java issues [Hardware Haven] had no interest in troubleshooting. Hardware wise, though, well — do you want to leave a phone plugged in permanently? Smokey the Bear suggests you not, especially if you live near a forest. Besides, you probably don’t want your server on WiFi, and at least this smartphone wouldn’t charge when using a networking dongle.

That meant phone surgery: the battery came out, and 5 V from an old USB charger was piped into the battery charge controller via a diode. The diode was used for its voltage drop, to bring the 5 V supply down to a believable battery voltage — a buck converter might have been better, but you use what you have, and the diode drop doesn’t dissipate much power. Power dissipation is still one watt at idle, six during a stress test.

Given how cheap the phone was, and how little power this thing sips, [Hardware Heaven] has an excellent answer to those who say homelabbing is a rich person’s hobby. This project also reminds us that while our phones might not be as hackable as we’d like, they’re still far from totally locked down. You can even run NixOS on (some of) them.

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