DIY Algae Biodiesel Is Harder Than You Think

October 6, 2026 by 6 Comments

There’s one thing [Silent H] wants you to know before you watch his video about making biodiesel, embedded below: he started this project before he’d even heard of the Strait of Hormuz. No, he’s just independent-minded and wanted to try making his own fuel when diesel was– in retrospect– cheap as chips. That’s probably a good thing, because while [Silent] gets his pint of fuel at the end of the video, it’s not from algae; it’s from a backup crop of sunflowers.

As it turns out, he picked what was the perfect algae and the absolute worst algae for making biodiesel from: Chlorella Vulgaris. It’s perfect because it’s easy to grow, and easy to extract from the growth medium, as it sinks when it is ‘ripe’, and has a very high oil content. Of course [Silent] didn’t want to toss algae cakes into a steam powered canoe, he wanted diesel fuel for his vehicle. That’s where the project broke down: Chlorella Vulgaris cells are exceptionally tough, and if you can’t rupture the cell wall, you can’t can’t get out any appreciable oil. A few grams by solvent extraction is all he manages before switching to more tractable feedstock.

That feedstock is sunflowers, which give up their oil through the application of violent pressure. That is to say, he crushes the seeds in an oil press. Oil acquired, he goes on to transesterfy the stuff, extracting glycerine to produce biodiesel– a process ripe for hacking that you’d think we’d cover more often.

We have covered the algae growth side of things before, but that algae seemed to be destined for other uses than fuel.

Continue reading “DIY Algae Biodiesel Is Harder Than You Think” →

SmallTV Hacking With Surprisingly Little Fuss

October 6, 2026 by 3 Comments

We’ve seen the GeekMagic SmallTV line of devices before — these cheap gadgets combine a microcontroller and a display in a little plastic case that can be used to show the time or weather. Powered by either an ESP8266 or an ESP32, the things could easily pass for a hobby build if it wasn’t for their professionally produced enclosures. In fact, we wouldn’t be surprised if GeekMagic lifted the idea from an existing DIY project.

As you might expect we’ve seen several hacks for these devices already, which usually involves replacing the stock firmware. But this latest approach is unique in that you don’t need to mess with the stock software, nor do you need to break out the soldering iron. By leveraging a built-in photo viewer function of the SmallTV [Yongha Kim] shows how you can get the gadget to display pretty much whatever you want.

The trick here is that the image is being generated by a machine on the network, say your desktop or server, and being pushed over to the SmallTV over HTTP. In this example the image is being generated in Python with the Pillow library, and [Yongha] has it showing Claude and Codex usage data, but you could really approach this however you wish.

All you need to do is create a 240×240 image and shoot it over to the device, so you’re free to come up with whatever sort of visuals you’d like. It even supports GIF if you’d like to work animation into it. The content can of course be whatever information you’re interested in showing, and it can be generated by whatever programming language or tool you’re most comfortable with. It’s a fascinating proof of concept, and now that the method has been demonstrated we’re interested to see where the community can take it.

If this all sounds a little too easy for your tastes, don’t worry. There’s a plenty deep rabbit hole you can dive into should you elect to replace the device’s firmware entirely.

Scientists Create Hexagonal Packed Ice At Extreme Pressures

October 6, 2026 by 7 Comments

One of the problems with planetary science is that you generally cannot easily investigate the exact conditions in their interior, so you’re left to extrapolate what is happening inside them based on surface scans. One of the resulting questions is what ice giants like Neptune and Uranus in Earth’s solar system have exactly at their core. We do know that it is mostly rocks and ice, but what kind of ice you end up with at these intense pressures is a good question that [Alexis Forestier] et al. set out to answer, with their results published in a Physical Review Letter paper (ArXiv preprint).

It’s noteworthy that there isn’t just water ice at these planetary cores, with this study only investigating water ice specifically. In order to get the water to the pressures it would experience courtesy of ice giant gravity, a diamond anvil was used, with synchrotron x-ray diffraction allowing for the changes to the sample to be observed.

The phase diagram of water includes a number of phases beyond what us Earth-dwellers would call ‘ice’, with at higher pressures above about 80 GPa the formation of ice X, featuring a body-centered cubic (BCC) oxygen sublattice. Subsequent discovered phases were face-centered cubic (FCC) and now hexagonal close-packed (HCP) ice, all differing in the packing of the oxygen sublattice.

In addition to extreme pressures, temperatures also had to be increased by using the laser heating feature of the diamond anvil. At around 2,000K and over 200 GPa the HCP phase was found, with a mixed FCC-HCP phase at intermediate pressures.

Although not immediately providing answers to questions pertaining to the aforementioned ice giants, it gives planetary scientists yet another clue that they can use in future investigations, as well as provide more insight into this most fascinating phase of water that’s actually its own little galaxy of phases.

A Headset Fit For A Hackaday Writer

October 6, 2026 by 7 Comments

I started writing this from a commuter train passing at speed through the outskirts of London, and my headset had just broken. The flexible joint that attaches one earpiece to the headband has snapped, leaving the earpiece dangling on its cable. This is annoying on its own, but what is annoying me enough to write about it is that this isn’t the first time. This is only the latest in a succession of headsets I’ve taken on the road with me has broken, not because of rough treatment, but simply due to flimsy or bad design. What on earth can I do about this?

Failure Built-In

The earpiece of an EPOS headset, detached from its band.
Failure inevitable: the whole headset relied on a tiny piece of plastic in the centre.

The most recent three have been a JVC whose rotating joint allowing the earpiece to lie at a slight angle with my ear has failed, a quite expensive Logitech whose ear sponges failed closely followed by its USB cable, and now an EPOS whose ball joint has failed.

I repaired the JVC and got a bit more life out of it and I’ll have a go at repairing this EPOS, but that’s hardly the point. I’m paying not inconsequential money and I’m getting good sound quality and electronics, but I’m not getting anywhere near the mechanical quality I need. I could buy a set of tough DJ headphones such as the Sennheiser HD25, but they don’t come with a microphone, they’re not a headset.

So if I can’t buy a decent headset without spending military grade money on one from an F16 fighter, what can I do to make my own? I’m an engineer, damnit!

At its most basic, a headset is a springy band that goes over the head, with an earpiece at its end. But a human head is not a cube with vertical parallel sides, it’s a complex shape and every one is different. So those earpieces have to have some “give” in them in order to fit comfortably against the ear. In the simplest case this is achieved by giving the earpiece a soft surround that moulds itself to the ear, but most headsets incorporate some articulation. The earpiece must rotate a little around a vertical line parallel with the ear, and also with a horizontal line at right angles to the axis of the ear. The EPOS managed both axes by means of a ball joint, while the JVC had a stirrup with pins to achieve the horizontal motion, and a circular joint — the part which broke — for the vertical. In both case the weak point was a thin part of the plastic moulding which broke, on the EPOS a short stalk for the ball in the ball joint, and in the JVC a similar stalk for the circular joint. Any design I come up with must avoid this type of weak point, and spread the load of an earpiece over considerably more material than my broken headset. Continue reading “A Headset Fit For A Hackaday Writer” →

The EDG C++ Compiler Frontend Has Been Open Sourced

October 6, 2026 by 5 Comments

Recently [John Spicer] of the EDG C++ compiler front-end project announced that the project will be made open source, from now on managed by the non-profit C++ Alliance. Related source code can be found on the GitHub account.

The Edison Design Group (EDG) is a US company which has made compiler front-ends since 1988, previously also for Java and Fortran. They are used in the Intel C++ compiler, Microsoft’s VC++, NVIDIA’s CUDA compiler, as well as many other commercial products. Last year the decision was made to shutdown the company in 2026 and transition to an open source model, with the details outlined on the EDGCPP site.

Although far from the only C++ front-end, EDGCPP will be very interesting still for supporting bleeding-edge features and having been used in such wide-ranging, demanding applications by a host of commercial customers. For most of us C++ developers our contact with it will have been via the MSVC and Intel Compiler Collection tooling, but of course it’s just one part of the entire toolset.

We’re looking forward to seeing what this means for the wider open source C++ ecosystem, especially as it pertains to GCC and LLVM’s Clang.

Using LineageOS For Phones And DIY Smart TVs Is Pretty Nifty

October 6, 2026 by 7 Comments

Although Android is essentially just another Linux distribution, most people only experience it in the form of the rather restrictive and proprietary versions found on smartphones, tablets and smart TVs. While this is probably fine for the average person, there’s also a lot to be said for the more pure Android experience in the form of LineageOS.

With this fully open and community-supported version of Android you’re free to muck about with your hardware to your heart’s content, without annoyances like unremovable bloatware apps and restrictions on e.g. enabling developer mode.

Even more fun is that there are ports of LineageOS to systems such as the Raspberry Pi SBC, including in the Android TV configuration. This means that not only can your ten year old Android phone get a make-over with a recent version of Android, you can also create your own Android TV-based smart TV without all the spying and other nasty things that commercial smart TVs love to do.

Continue reading “Using LineageOS For Phones And DIY Smart TVs Is Pretty Nifty” →

USB-C PD Tamed With This Analyzer

October 6, 2026 by 10 Comments

USB-C Power Delivery (PD) has been a boon to anyone working with low-voltage DC power, because at a stroke it replaces a vast array of wall warts, power supplies, and connector standards with one simple and straightforward commoditized system. But with varying capabilities between sources and sinks, it can be difficult to know what’s going on.

[Marco Tabini] has created Dr. PD, a USB -C PD protocol analyzer. It can sit between USB-C PD source and sink, or emulate a sink in order to characterize a source. It supports an impressive range of USB power protocols, and can work up to the full 48 volt/240 watt limits of the technology. The project is open source and is to be the subject of a crowdfunding campaign should you want one without the extra work.

It’s likely that many of you will have had bad experiences with cheap USB-C PD gear failing to follow standards, being unable to handle the specified current, or just plain supplying the wrong voltage. We have, and while USB-C PD is genuinely a great technology, this regrettable hardware represents its grubby underbelly. This is just the project we need on the bench in our hackerspace.

In the past we’ve written about USB-C PD as a great example of new technology done right.