Minecraft Finally Gets Multi-Threaded Servers

April 3, 2023 by 33 Comments

Minecraft servers are famously single-threaded and those who host servers for large player bases often pay handsomely for a server that has gobs of memory and ripping fast single-core performance. Previous attempts to break Minecraft into separate threads haven’t ended successfully, but it seems like the folks over at [PaperMC] have finally cracked it with Folia.

Minecraft is one of (if not the most) hacked and modded games in history. Mods have been around since the early days, made possible by a dedicated group who painstakingly decompiled the Java bytecode and reverse-engineered it. Bukkit was a server mod back in the Alpha days that tried to support plugins and extend the default Minecraft. From Bukkit, Spitgot was forked. From Spitgot, Paper was forked, which focused on performance and gameplay mechanics. And now from Paper, Folia is a new fork focused on multi-threading.

A Minecraft world is split up into worlds (such as the nether or the overworld) and chunks. Chunks are 16x16xZ vertical columns of blocks. Folia breaks up sections of chunks into regions that can be ticked independently. Of course, moving to a multi-threaded model will cause existing plugins to fail. Very little was made thread-safe and the idea is that data cannot move easily across ticking regions. Regions tick in parallel, not synchronously.

Naturally, the people benefiting from Folia the most are those running servers that support hundreds of players. On a server with a vanilla-like configuration only around a hundred or so players can be online. Increasing single-core performance isn’t usually an option past this point. By moving to other cores, suddenly you can scale out significantly without restoring to complex proxying. Previous attempts have had multiple Minecraft servers and then synced players and entities between them. Of course, this can cause its own share of issues.

It’s simply incredible to us what the modding community continues to develop and create. It takes deep patience to reverse-engineer the system and rearchitect it from the outside. The Folia codebase is available on GitHub under a GNU GPL 3.0 license if you’d like to look through it.

Tennis Balls Serve As Decent Bicycle Tires That Don’t Easily Puncture

April 3, 2023 by 41 Comments

Pneumatic tires provide a great ride, great grip, and yet have one fatal flaw — they’re always getting punctured and leaving you stranded. [The Q] decided to solve this problem with a unique design: tires that use tennis balls as the cushioning medium instead.

The build begins with small cut sections of plastic water pipe. These are used as housings to hold tennis balls, which are pressed in with a unique tool of [The Q]’s own construction. The individual ball assemblies are then bolted into a standard bicycle wheel, and a tread from a regular bike tire is stretched around the outside for grip.

It goes without saying that these tires won’t offer the same quality of ride as regular pneumatic bike tires. Nor will the performance be as good, due to the significant extra unsprung weight. They are eye-catching and fun, however. Plus, if you live in an area with tons of nails or prickles, you might find these are just the ticket. Maybe.

We’ve seen some other great bike hacks before, too.

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A shot of the underside of a "One Fast Cat" cat wheel with an installed ESP8266 and hall effect sensors attached to the base.

Spy On Your Cat To Make Sure It Gets Its Paws In

April 2, 2023 by 8 Comments

[Scott Cutler] has a young cat, [Cygnus], that loves to run on a cat wheel and [Scott] had some some important questions about [Cygnus]’s usage of the cat wheel like, how often it’s used, what direction is preferred and how fast does [Cygnus] go. To answer these questions, [Scott] put some telemetry sensors onto the cat wheel and analyzed the results.

An ESP8266 microcontroller and two 3144E hall effect modules were used to sense eight magnets glued onto the outer housing of a “One Fast Cat” cat wheel. [Scott] installed the ESP8266 and hall effect modules onto the base support for the wheels, using 3D printed brackets to secure them.

For the software side, the ESP8266 attaches an interrupt handler whenever a sensor passes by, recording a window of three previous measurements for valid sample determination and, if accepted, uses the time between samples to infer direction and speed. The ESP8266 connects to a pre-configured local WiFi network and has a telnet interface to extract stored log information, in the form of JSON data.

[Scott] has some nice graphs and other data visualizations on [Cygnus]’s usage, including a preference for running at 3 AM, achieving a maximum speed of 14 mph and an average of 4 seconds per run. The source is available on GitHub and the STL files are available embedded in [Scott]’s write-up. We’ve featured cat exercise trackers before with a giant hamster wheel outfitted with a Raspberry Pi and it’s nice to see some options that allow for a retrofit option in addition to a complete DIY solution.

Sound Sculpture Uses Daisy Seed To Generate Audio

April 2, 2023 by No comments

Here at Hackaday, we love a good art piece, whether that involves light or sound. Combining both is a sure-fire way to get our attention, and [Eirik Brandal] did just that with his Void Extrusion piece.

The project is built around the Daisy Seed from Electrosmith. It’s an embedded platform designed for musical purposes, which made it perfect for [Eirik]’s project. Based on an STM32 chip, it’s very capable when it comes to DSP tasks. In this role, it’s charged with algorithmic music composition, providing the captivating soundtrack that emanates from the sculpture.

The sculpture itself looks almost like a fancy mid-century home from the Hollywood Hills, but it’s fundamentally a little more abstract than that. [Eirik] built it as an opportunity to experiment with using 3D printed forms in his work. To that end, it features a beautiful diffused LED wall and a speaker enclosure as an integral part of the build. The LEDs are run from an Arduino Nano Every.

[Eirik’s] work shows us that “generative” music can be intoxicating and compelling with a real sense of feeling and mood. The sculpture is a visually-capable pairing that works with the soundscape. It recalls us of some other great artworks we’ve featured from [Eirik] before, too.

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Hackaday Links: April 2, 2023

April 2, 2023 by 1 Comment

It may be hard to believe, but it’s time for the Hackaday Prize again! The 2023 Hackaday Prize was announced last weekend at Hackaday Berlin, and entries are already pouring in. The first-round challenge is all about “Re-engineering Education,” which means you’ve got to come up with a project idea that helps push back the veil of ignorance somehow. Perhaps you’ve got a novel teaching tool in mind, or a way to help students learn remotely. Or maybe your project is aimed at getting students involved and engaged. Whatever it is — and whatever the subject matter; it doesn’t just have to be hacking-adjacent — get an entry together, build a team, and get to work. The first round closes on April 25, so get to it!

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Visual Ear Demonstrates How The Cochlea Works

April 2, 2023 by 13 Comments

The cochlea is key to human hearing, and it plays an important role in our understanding of complex frequency content. The Visual Ear project aims to illustrate the cochlear mechanism as an educational tool.

The cochlea itself is the part of the ear that converts the pressure waves of sound into electrical signals for the brain. Different auditory frequencies excite different parts of the cochlea. The cells in the different parts of the cochlea then send signals to the brain corresponding to the sound it has picked up.

The Visual Ear demonstrates similar behavior on a strip of addressable LEDs. Lower LEDs coded in the red part of the color spectrum respond to low frequency audio. Higher LEDs step through yellow, green, and up to blue, and respond to the higher frequencies in turn. This is achieved at a high response rate with the use of a Teensy 4.0 running a Fast Fourier Transform on incoming audio, and then outputting signals to run a string of WS2812B LEDs. The result is a visual band display of 104 bands spanning 43 Hz up to 16,744 Hz, which covers most but not all of the human range of hearing.

It’s an impressive display, and one that makes a great music visualizer, too. When teaching the physics of human hearing and the cochlea, we can imagine such a tool would be quite useful.

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Tour A PCB Assembly Line From Your Armchair

April 2, 2023 by 15 Comments

Those of us who build our own electronics should have some idea of the process used to assemble modern surface-mount printed circuit boards. Whether we hand-solder, apply paste with a syringe, use a hotplate, or go the whole hog with stencil and oven, the process of putting components on boards and soldering them is fairly straightforward. It’s the same in an industrial setting, though perhaps fewer of us will have seen an industrial pick-and-place line in action. [Martina] looks at just such a line for us, giving a very accessible introduction to the machines and how they are used. Have a look, in the video below the break.

It’s particularly interesting as someone used to the home-made versions of these machines, to see the optical self-alignment and the multiple pick-and-place tools which are beyond the simpler pick-and-place machines you’ll find in a hackerspace. Multiple machines in a line are also beyond hackerspaces, so the revelation that the first machine is deliberately run slowly to avoid the line backing up is a valuable one.

At the end of the line is the reflow oven itself, through which the boards pass on a belt through carefully graded hot air zones. Certainly a step up from a toaster oven with an Arduino controller!

Sadly not all of us will be lucky enough to have such a line at our disposal, but pick-and-place projects come up here quite often. We did a teardown on the feeders from a Siemens machine a couple of years ago.

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