A3 Audio: The Open Source 3D Audio Control System

June 7, 2024 by 8 Comments

Sometimes, startups fail due to technical problems or a lack of interest from potential investors and fail to gain development traction. This latter case appears to be the issue befalling A3 Audio. So, the developers have done the next best thing, made the project open source, and are actively looking for more people to pitch in. So what is it? The project is centered around the idea of spatial audio or 3D audio. The system allows ‘audio motion’ to be captured, mixed and replayed, all the while synchronized to the music. At least that’s as much as we can figure out from the documentation!

The system is made up of three main pieces of hardware. The first part is the core (or server), which is essentially a Linux PC running an OSC (Open Sound Control) server. The second part is a ‘motion sampler’, which inputs motion into the server. Lastly, there is a Mixer, which communicates using the OSC protocol (over Ethernet) to allow pre-mixing of spatial samples and deployment of samples onto the audio outputs. In addition to its core duties, the ‘core’ also manages effects and speaker handling.

The motion module is based around a Raspberry Pi 4 and a Teensy microcontroller, with a 7-inch touchscreen display for user input and oodles of NeoPixels for blinky feedback on the button matrix. The mixer module seems simpler, using just a Teensy for interfacing the UI components.

We don’t see many 3D audio projects, but this neat implementation of a beam-forming microphone phased array sure looks interesting.

Retrotechtacular: TVO

June 6, 2024 by 19 Comments

Hardware hackers come from a variety of backgrounds, but among us there remains a significant number whose taste for making things was forged through growing up in a farm environment. If that’s you then like me it’s probable that you’ll melt a little at the sight of an older tractor, and remember pretending to drive one like it at pre-school age, and then proudly driving it for real a few years later before you were smart enough to realise you’d been given the tedious job of repeatedly traversing a field at a slow speed in the blazing sun. For me those machines were Ford Majors and 5000s, Nuffields, the ubiquitous red Fergusons, and usually relegated to yard duty by the 1970s, the small grey Ferguson TE20s that are in many ways the ancestor of all modern tractors.

The Black Art Of Mixing Your Own Fuel

There was something odd about some of those grey Fergies in the 1970s, they didn’t run on diesel like their newer bretheren, nor did they run on petrol or gasoline like the family Austin. Instead they ran on an unexpected mixture of petrol and heating oil, which as far as a youthful me could figure out, was something of a black art to get right. I’d had my first encounter with Tractor Vapour Oil, or TVO, a curious interlude in the history of agricultural engineering. It brings together an obscure product of the petrochemical industry, a moment when diesel engine technology hadn’t quite caught up with the on-farm requirement, and a governmental lust for a lower-tax tractor fuel that couldn’t be illicitly used in a car.

TVO is a fuel with a low octane rating, where the octane rating is the resistance to ignition through compression alone. In chemical terms octane rating a product of how many volatile aromatic hydrocarbons are in the fuel, and to illustrate it your petrol/gasoline has an octane rating in the high 90s, diesel fuel has one close to zero, and TVO has a figure in the 50s. In practice this was achieved at the refinery by taking paraffin, or kerosene for Americans, a heavier fraction than petrol/gasoline, and adding some of those aromatic hydrocarbons to it. The result was a fuel on which a standard car engine wouldn’t run, but which would run on a specially low-compression engine with a normal spark ignition. This made it the perfect tax exempt fuel for farmers because it could only be used in tractors equipped with these engines, and thus in the years after WW2 a significant proportion of those Fergies and other tractors were equipped to run on it. Continue reading “Retrotechtacular: TVO” →

A Treasure Trove In An English Field

June 3, 2024 by 12 Comments

This is being written in a tent in a field in Herefordshire, one of the English counties that borders Wales. It’s the site of Electromagnetic Field, this year’s large European hacker camp, and outside my tent the sky is lit by a laser light show to the sound of electronic music. I’m home.

One of the many fun parts of EMF is its swap table. A gazebo to which you can bring your junk, and from which you can take away other people’s junk. It’s an irresistible destination which turns a casual walk into half an hour pawing through the mess in search of treasure, and along the way it provides an interesting insight into technological progress. What is considered junk in 2024?

Something for everyone

As always, the items on offer range from universal treasures of the I-can’t-believe-they-put that-there variety, through this-is-treasure-to-someone-I’m-sure items, to absolute junk. Some things pass around the camp like legends; I wasn’t there when someone dropped off a box of LED panels for example, but I’ve heard the story relayed in hushed tones several times since, and even seen some of the precious haul. A friend snagged a still-current AMD processor and some Noctua server fans as another example, and I’m told that amazingly someone deposited a Playstation 5. But these are the exceptions, in most cases the junk is either very specific to something, or much more mundane. I saw someone snag an audio effects unit that may or may not work, and there are PC expansion cards and outdated memory modules aplenty.

Finally, there is the absolute junk, which some might even call e-waste but I’ll be a little more charitable about. Mains cables, VGA cables, and outdated computer books. Need to learn about some 1990s web technology? We’ve got you covered. Continue reading “A Treasure Trove In An English Field” →

A small internet radio in 3D-printed case with a knob and an OLED screen.

GlobeTune Will Widen Your Musical Horizons

June 1, 2024 by 12 Comments

Are you tired of the same old music, but can’t afford any new tunes, even if they’re on dead formats? Boy, do we know that feeling. Here’s what you do: build yourself a GlobeTune music player, and you’ll never want for new music again.

The idea is simple, really. Just turn what we assume is a nice, clicky knob, and after a bit of static (which is a great touch!), you get a new, random radio station from somewhere around the globe. [Alexis D.] originally built this as a way to listen to and discover new music while disconnecting from the digital world, and we think it’s a great idea.

[Alexis D.] has production in mind, so after a Raspberry Pi Zero W prototype, they set about redesigning it around the ESP32. The current status seems to be hardware complete, software forthcoming. [Alexis D.] says that a crowdfunding campaign is in the works, but that the project will be open-sourced once in an acceptable state. So stay tuned!

Speaking of dead-ish formats, here’s an Internet radio in a cassette form factor.

The Tragic Story Of The Ill-Fated Supergun

May 28, 2024 by 63 Comments

In the annals of ambitious engineering projects, few have captured the imagination and courted controversy quite like Gerald Bull’s Supergun. Bull, a Canadian artillery expert, envisioned a gun that could shoot payloads directly into orbit. In time, his ambition led him down a path that ended in both tragedy and unfinished business.

Depending on who you talk to, the Supergun was either a new and innovative space technology, or a weapon of war so dangerous, it couldn’t be allowed to exist. Ultimately, the powers that be intervened to ensure we would never find out either way.

Continue reading “The Tragic Story Of The Ill-Fated Supergun” →

So What’s All This HaLow Long-Range WiFi About Then?

May 26, 2024 by 18 Comments

We’re all used to wireless networking, but if there’s one thing the ubiquitous WiFi on 2.4 or 5 GHz lacks, it’s range. Inside buildings, it will be stopped in its tracks by anything more than a mediocre wall, and outside, it can be difficult to connect at any useful rate more than a few tens of metres away without resorting to directional antennas and hope. Technologies such as LoRa provide a much longer range at the expense of minuscule bandwidth, but beyond that, there has been little joy. As [Andreas Spiess] points out in a recent video though, this is about to change, as devices using the so-called HaLow or IEEE 802.11ah protocol are starting to edge into the realm of affordability.

Perhaps surprisingly, he finds the 5 GHz variant to be best over a 1km test with a far higher bandwidth. However, we’d say that his use of directional antennas is something of a cheat. Where it does come into its own in his tests, though, is through masonry, with far better penetration across floors of a building. We think that this will translate to better outdoor performance when the line of sight is obstructed.

There’s one more thing he brings to our attention, which seasoned users of LoRA may already be aware of. These lower frequency allocations are different between the USA and Europe, so should you order one for yourself, it would make sense to ensure you have the appropriate model for your continent. Otherwise, we look forward to more HaLow devices appearing and the price falling even further because we think this will lead to some good work in future projects.

Continue reading “So What’s All This HaLow Long-Range WiFi About Then?” →

ArdEEG Lowers The Cost Of Brain-Computer Interfaces

May 8, 2024 by 22 Comments

Considering the incredible potential offered by brain-computer interfaces (BCIs), it’s no wonder there are so many companies scrambling to make their mark in the field. Some see it as an assistive technology, while others imagine it as the future of interactive entertainment. Regardless of the application, the technology has yet to make much inroads with the DIY crowd — largely due to the complexity and cost of the hardware involved.

But that might change in the near future thanks to projects like ardEEG from [Ildar Rakhmatulin]. This open source shield mounts to the top of the Arduino UNO R4 WiFi and features eight channels for collecting electroencephalogram (EEG) data, such as from a dry electrode cap. The signals can then be processed on the computer using the provided Python example code. From there, the raw data can be visualized or plugged into whatever application you have in mind.

Why target the relatively uncommon WiFi version of the Uno? It’s probably obvious for those with experience with this kind of hardware, but for safety, the system needs complete electrical isolation. The Arduino and shield are powered by a common USB battery bank, and all communication is done over WiFi. Even still, the documentation is clear that the ardEEG is not a medical device, and hasn’t been certified by any regulatory agency — its use is entirely at your own risk.

[Ildar] tells us the hardware will be available soon and should cost under $250, making it one of the most affordable BCI development platforms out there. As with his earlier PiEEG project, the hope is that basing the system around a common device in the hacker and maker scene will help democratize access to BCI research.

Continue reading “ArdEEG Lowers The Cost Of Brain-Computer Interfaces” →