E-Waste And Waste Oil Combine To Make Silver

September 14, 2025 by Tyler August 12 Comments

As the saying goes, “if it can’t be grown, it has to be mined”– but what about all the metals that have already been wrested from the bosom of the Earth? Once used, they can be recycled– or as this paper charmingly puts it, become ore for “urban mining” techniques. The technique under discussion in the Chemical Engineering Journal is one that extracts metallic silver from e-waste using fatty acids and hydrogen peroxide.

This “graphical abstract” gives the rough idea.

Right now, recycling makes up about 17% of the global silver supply. As rich sources of ore dry up, and the world moves to more sustainable footing, that number can only go up. Recycling e-waste already happens, of course, but in messy, dangerous processes that are generally banned in the developed world. (Like open burning, of plastic, gross.)

This paper describes a “green” process that even the most fervant granola-munching NIMBY wouldn’t mind have in their neighborhood: hot fatty acids (AKA oil) are used as an organic solvent to dissolve metals from PCB and wire. The paper mentions sourcing the solvent from waste sunflower, safflower or canola oil. As you might imagine, most metals, silver included, are not terribly soluble in sunflower oil, but a little refining and the addition of 30% hydrogen peroxide changes that equation.

More than just Ag is picked up in this process, but the oils do select for silver over other metals. The paper presents a way to then selectively precipitate out the silver as silver oleate using ethanol and flourescent light. The oleate compound can then be easily washed and burnt to produce pure silver.

The authors of the paper take the time to demonstrate the process on a silver-plated keyboard connector, so there is proof of concept on real e-waste. Selecting for silver means leaving behind gold, however, so we’re not sure how the economics of this method will stack up.

Of course, when Hackaday talks about recycling e-waste, it’s usually more on the “reuse” part of “reduce, reuse, recycle”. After all, one man’s e-waste is another man’s parts bin–or priceless historical artifact.

Thanks to [Brian] for the tip.Your tips can be easily recycled into Hackaday posts through an environmentally-friendly process via our tipsline.

Aussie Researchers Say They Can Bring The Iron Age To Mars

September 13, 2025 by Tyler August 44 Comments

It’s not martian regolith, bu it’s the closest chemical match available to the dirt in Gale Crater. (Image: Swinburne University)

Every school child can tell you these days that Mars is red because it’s rusty. The silicate rock of the martian crust and regolith is very rich in iron oxide. Now Australian researchers at CSIRO and Swinburn University claim they know how to break that iron loose.

In-situ Resource Utilization (IRSU) is a big deal in space exploration, with good reason. Every kilogram of resources you get on site is one you don’t have to fight the tyranny of the rocket equation for. Iron might not be something you’d ever be able to haul from Earth to the next planet over, but when you can make it on site? You can build like a Victoria is still queen and it’s time to flex on the French.

The key to the process seems to be simple pyrolysis: they describe putting dirt that is geochemically analogous to martian regolith into a furnace, and heating to 1000 °C under Martian atmospheric conditions to get iron metal. At 1400 °C, they were getting iron-silicon alloys– likely the stuff steelmakers call ferrosilicon, which isn’t something you’d build a crystal palace with.

It’s not clear how economical piling red dust into a thousand-degree furnace would be on Mars– that’s certainly not going to cut it on Earth– but compared to launch costs from Earth, it’s not unimaginable that martian dirt could be considered ore.

ESP32 Hosts Functional Minecraft Server

September 13, 2025 by Tyler August 11 Comments

If you haven’t heard of Minecraft, well, we hope you enjoyed your rip-van-winkle nap this past decade or so. For everyone else, you probably at least know that this is a multiplayer, open world game, you may have heard that running a Minecraft server is a good job for maxing out a spare a Raspberry Pi. Which is why we’re hugely impressed that [PortalRunner] managed to squeeze an open world onto an ESP32-C3.

Of course, the trick here is that the MCU isn’t actually running the game — it’s running bareiron, [PortalRunner]’s own C-based Minecraft server implementation. Rewriting the server code in C allows it to be optimized for the ESP32’s hardware, but it also let [PortalRunner] strip his server down to the bare essentials, and tweak everything for performance. For example, instead of the multiple octaves of Perlin noise for terrain generation, with every chunk going into RAM, he’s using the x and z of the corners as seeds for the psudorandom rand() function, and interpolating between them. Instead of caves being generated by a separate algorithm, and stored in memory, in bareiron the underground is just a mirror-image of the world above. Biomes are just tiled, and sit separately from one another.

So yes, what you get from bareiron is simpler than a traditional Minecraft world — items are simplified, crafting is simplified, everything is simplified, but it’s also running on an ESP32, so you’ve got to give it a pass. With 200 ms to load each chunk, it’s playable, but the World’s Smallest Minecraft Server is a bit like a dancing bear: it’s not about how well it dances, but that it dances at all.

This isn’t the first time we’ve seen Minecraft’s server code re-written: some masochist did it in COBOL, but at least that ran on an actual computer, not a microcontroller. Speaking of low performance, you can’t play Minecraft on an SNES, but you can hide the game inside a cartridge, which is almost as good.

Thanks to [CodeAsm] for the tip. Please refer any other dancing bears spotted in the wild to our tips line.

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Musical Motors, BLDC Edition

September 12, 2025 by Tyler August 21 Comments

This should count as a hack: making music from a thing that should not sing. In this case, [SIROJU] is tickling the ivories with a Brushless DC motor, or BLDC.

To listen to a performance, jump to 6:27 in the embedded video. This BLDC has a distinctly chip-tune like sound, not entirely unlike other projects that make music with stepper motors. Unlike most stepper-based instruments we’ve seen [SIROJU]’s BLDC isn’t turning as it sings. He’s just got it vibrating by manipulating the space vector modulation that drives the motor — he gets a response of about 10 kHz that way. Not CD-quality, no, but plenty for electronic music. He can even play chords of up to 7 notes at a time.

There’s no obvious reason he couldn’t embed the music into a proper motor-drive signal, and thus allow a drone to hum it’s own theme song as it hovers along. He’s certainly got the chops for it; if you haven’t seen [SIROJU]’s videos on BLDC drivers on YouTube, you should check out his channel. He’s got a lot of deep content about running these ubiquitous motors. Sure, we could have just linked to him showing you how to do FOC on an STM32, but “making it sing” is an expression for mastery in English, and a lot more fun besides.

There are other ways to make music with motors. If you know of any others, don’t hesitate to send us a tip.

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Old Phone Upcycled Into Pico Projector, ASMR

September 11, 2025 by Tyler August 30 Comments

To update an old saying for the modern day, one man’s e-waste is another man’s bill of materials. Upcycling has always been in the hacker’s toolkit, and cellphones provide a wealth of resources for those bold enough to seize them. [Huy Vector] was bold enough, and transformed an old smartphone into a portable pico projector and an ASMR-style video. That’s what we call efficiency!

Kidding aside, the speech-free video embedded below absolutely gives enough info to copy along with [Huy Vector] even though he doesn’t say a word the whole time. You’ll need deft hands and a phone you really don’t care about, because one of the early steps is pulling the LCD apart to remove the back layers to shine an LED through. You’ll absolutely need an old phone for that, since that trick doesn’t apply to the OLED displays that most flagships have been rocking the past few years.

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65F02 Is An FPGA 6502 With A Need For Speed

September 10, 2025 by Tyler August 8 Comments

Does the in 65F02 “F” stand for “fast” or “FPGA”? [Jurgen] doesn’t know, but his drop-in replacement board for the 6502 and 65c02 is out there and open source, whatever you want it to stand for.

The “f” could easily be both, since at 100 MHz, the 65f02 is blazing fast by 6502 standards–literally 100 times the speed of the first chips from MOS. That speed comes from the use of a Spartan 6 FPGA core to implement the 6502 logic; making the “f” stand for “FPGA” makes sense, given that the CMOS version of the chip was dubbed the 65c02. The 65f02 is a tiny PCB containing the FPGA and all associated hardware that shares the footprint of a DIP-40 package, making it a drop-in replacement. A really fast drop-in replacement.

You might be thinking that that’s insane, and that (for example) the memory on an Apple ][ could never run at 100 MHz and so you won’t get the gains. This is both true, and accounted for: the 65F02 has an internal RAM “cache” that it mirrors to external memory at a rate the bus can handle. When memory addresses known to interact with peripherals change, the 65f02 slows down to match for “real time” operations.

The USB adapter board for programming is a great touch.

Because of this the memory map of the external machine matters; [Jurgen] has tested the Commodore PET and Apple ][, along with a plethora of German chess computers, but, alas, this chip is not currently compatible with the Commodore 64, Atari 400/800 or BBC Micro (or at least not tested). The project is open source, however, so you might be able to help [Jurgen] change that.

We admit this project isn’t totally new– indeed, it looks like [Jurgen]’s last update was in 2024– but a fast 6502 is just as obsolete today as it was when [Jurgen] started work in 2020. That’s why when [Stephen Walters] sent us the tip (via electronics-lab), we just had to cover it, especially considering the 6502’s golden jubilee.

We also recently featured a 32-bit version of the venerable chip that may be of interest, also on FPGA.

The weaving is on the left, a microphoto of the chip die is on the right.

The 555 As You’ve Never Seen It: In Textile!

September 10, 2025 by Tyler August 12 Comments

The Diné (aka Navajo) people have been using their weaving as trade goods at least since European contact, and probably long before. They’ve never shied from adopting innovation: churro sheep from the Spanish in the 17th century, aniline dies in the 19th, and in the 20th and 21st… integrated circuits? At least one Navajo Weaver, [Marilou Schultz] thinks they’re a good match for the traditional geometric forms. Her latest creation is a woven depiction of the venerable 555 timer.

“Popular Chip” by Marilou Schultz. Photo courtesy of First American Art Magazine, via righto.com

This isn’t the first time [Marilou] has turned an IC into a Navajo rug; she’s been weaving chip rugs since 1994– including a Pentium rug commissioned by Intel that hangs in USA’s National Gallery of Art–but it’s somehow flown below the Hackaday radar until now. The closest thing we’ve seen on these pages was a beaded bracelet embedding a QR code, inspired by traditional Native American forms.

That’s why we’re so thankful to [VivCocoa] for the tip. It’s a wild and wonderful world out there, and we can’t cover all of it without you. Are there any other fusions of tradition and high-tech we’ve been missing out on? Send us a tip.