8-Core ARM Pocket Computer Runs NixOS

July 17, 2025 by Tyler August 6 Comments

What has 8 ARM cores, 8 GB of RAM, fits in a pocket, and runs NixOS? It’s no pi-clone SBC, but [MWLabs]’s smartphone– a OnePlus 6, to be precise.

The video embedded below, and the git link above, are [MWLabs]’s walk-through for loading the mobile version of Nix onto the cell phone, turning it into a tiny-screened Linux computer. He’s using the same flake on the phone as on his desktop, which means he gets all the same applications set up in the same way– talk about convergence. That’s an advantage to Nix in this application, compared to the usual Alpine-based PostMarketOS.

Of course some of the phone-like features of this pocket-computer are lacking: the SIM is detected, and he can text, but 4G is nonfunctional. The rear camera is also not there yet, but given that Mobile-NixOS builds on the work done by well-established PostMarketOS, and PostMarketOS’ testing version can run the camera, it’s only a matter of time before support comes downstream. Depending what you need a tiny Linux device for, the camera functionality may or may not be of particular interest. If you’re like us, the idea of a mobile device running Nix might just intrigue you,

Smartphones can be powerful SBC alternatives, after all. You can even turn them into SBCs. As long as you don’t need a lot of GPIO, like for a server,a phone in hand might be worth two birds in the raspberry bush.

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ESP32 Plugs In To Real-Time Crypto Prices

July 17, 2025 by Bryan Cockfield 7 Comments

In today’s high-speed information overload environment, we often find ourselves with too much data to take in at once, causing us to occasionally miss out on opportunities otherwise drowned out in noise. None of this is more evident in the realm of high-speed trading, whether it’s for stocks, commodities, or even crypto. Most of us won’t be able to build dedicated high speed connections directly to stock exchanges for that extra bit of edge over the other traders, but what we can do is build a system that keys us in to our cryptocurrency price of choice so we know exactly when to pull the trigger on a purchase or sale.

[rishab]’s project for doing this is based on an ESP32 paired with a 10″ touchscreen display. It gathers live data from Binance, a large cryptocurrency exchange that maintains various pieces of information about many digital currencies. [rishab]’s tool offers a quick, in-depth look at a custom array of coins, with data such as percentage change over a certain time and high and low values for that coin as well. The chart updates in real time, and [rishab] also built a feature in which scales coins up if they have been seeing large movements in price over short timeframes.

Although it’s not a direct fiber link into an exchange, it certainly has its advantages over keeping this information in a browser window on a computer where it could get missed, and since it’s dedicated hardware running custom firmware it can show you exactly what you need to see if you’re day trading crypto. Certainly projects like this are in the DIY spirit that crypto enthusiasts tout as ideals of the currency, and as people move away from mining and more into speculative trading we’d expect to see more projects like this.

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A photo of a Stirling Engine attached to a bike

Building A Stirling Engine Bike

July 17, 2025 by John Elliot V 25 Comments

Over on his YouTube channel [Tom Stanton] shows us how to build a Stirling Engine for a bike.

A Stirling Engine is a heat engine, powered by the expansion and contraction of a working fluid (such as air) which is heated and cooled in a cycle. In the video [Tom] begins by demonstrating the Stirling Engine with some model engines and explains the role of the displacer piston. His target power output for his bike engine is 150 watts (about 0.2 horsepower) which is enough power to cycle at about 15 mph (about 24 km/h). After considering a CPU heatsink as the cooling system he decided on water cooling instead.

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2025 One Hertz Challenge: Building A Better Jumping Bean

July 17, 2025 by Seth Mabbott 4 Comments

Do you feel nostalgia for a childhood novelty toy that had potential but ultimately fell short of its promise? Do you now have the skills to go make a better version of that toy to satisfy your long-held craving? [ExpensivePlasticCrap] does and has set off on a mission to make a better jumping bean.

Jumping beans, the phenomenon on which the novelty of [ExpensivePlasticCrap]’s childhood is based, are technically not beans, and their movement is arguably not a jump — a small hop at best. The trick is that the each not-a-bean has become the home to moth larvae that twitches and rolls on the ground as the larvae thrash about, trying to move their protective shells out of the hot sun.

The novelty bean was a small plastic pill-like capsule with a ball bearing inside what would cause the “bean” to move in unexpected ways as it rolled around. [ExpensivePlasticCrap]’s goal is to make a jumping bean that lives up to its name.

Various solenoids and motors were considered for the motion component of this new and improved bean. Ultimately, it was a small sealed vibrating motor that would be selected to move the bean without getting tangled in what was to become a compact bundle of components.

An ATtiny microcontroller won out over discrete components for the job of switching the motor on and off (once per second), for ease of implementation. Add this along with a MOSFET, battery and charging board for power into a plastic capsule, and the 1 Hz jumping bean was complete.

[ExpensivePlasticCrap] offers some thoughts on how to get more jump out of the design by reducing the weight of the build and giving it a more powerful source of motion.

If insect-inspired motion gets you jumping, check out this jumping robot roach and these tiny RoboBees.

The Apollo–Soyuz Legacy Lives On, Fifty Years Later

July 17, 2025 by Tom Nardi 10 Comments

On this date in 1975, a Soviet and an American shook hands. Even for the time period, this wouldn’t have been a big deal if it wasn’t for the fact that it happened approximately 220 kilometers (136 miles) over the surface of the Earth.

Although their spacecraft actually launched a few days earlier on the 15th, today marks 50 years since American astronauts Thomas Stafford, Vance Brand, and Donald “Deke” Slayton docked their Apollo spacecraft to a specifically modified Soyuz crewed by Cosmonauts Alexei Leonov and Valery Kubasov. The two craft were connected for nearly two days, during which time the combined crew was able to freely move between them. The conducted scientific experiments, exchanged flags, and ate shared meals together.

Politically, this very public display of goodwill between the Soviet Union and the United States helped ease geopolitical tensions. On a technical level, it not only demonstrated a number of firsts, but marked a new era of international cooperation in space. While the Space Race saw the two counties approach spaceflight as a competition, from this point on, it would largely be treated as a collaborative endeavour.

The Apollo–Soyuz Test Project lead directly to the Shuttle–Mir missions of the 1990s, which in turn was a stepping stone towards the International Space Station. Not just because that handshake back in 1975 helped establish a spirit of cooperation between the two space-fairing nations, but because it introduced a piece of equipment that’s still being used five decades later — the Androgynous Peripheral Attach System (APAS) docking system.

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ProtoWeb: Browsing The Information Superhighway Like It’s 1995

July 17, 2025 by John Elliot V 19 Comments

Feeling nostalgic? Weren’t around in the 90s but wonder what it was like? ProtoWeb has you covered! Over on his YouTube channel [RetroTech Chris] shows you how to browse the web like it’s 1995.

The service that [RetroTech Chris] introduces is on the web over here: protoweb.org. The way it works is that you configure your browser to use the service’s proxy server, then the service will be able to intercept your browsing activity and serve you old content from its cache. Also, for some supported sites, you will see present-day content but presented in the format you would have seen in the 90s. Once you have configured your browser to use the ProtoWeb proxy you can navigate to http://www.inode.com/ where you will find a directory listing of sites which have been archived or emulated within the service.

In his video [RetroTech Chris] actually demos some of the old web browsers running on old hardware, which is a very good recreation of what things were like. If you want the most realistic experience you can even configure ProtoWeb to slow down your network connection to the speed of a 56k dial-up modem. There are some things from the 90s that we miss, but waiting for websites to load isn’t one of them!

We had a look in our own archive to see how far back we here at Hackaday could go, and we found our first post, from September 2004: Radioshack Phone Dialer – Red Box. A red box! Spicy.

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A Field Guide To The North American Cold Chain

July 17, 2025 by Dan Maloney 20 Comments

So far in the “Field Guide” series, we’ve mainly looked at critical infrastructure systems that, while often blending into the scenery, are easily observable once you know where to look. From the substations, transmission lines, and local distribution systems that make up the electrical grid to cell towers and even weigh stations, most of what we’ve covered so far are mega-scale engineering projects that are critical to modern life, each of which you can get a good look at while you’re tooling down the road in a car.

This time around, though, we’re going to switch things up a bit and discuss a less-obvious but vitally important infrastructure system: the cold chain. While you might never have heard the term, you’ve certainly seen most of the major components at one time or another, and if you’ve ever enjoyed fresh fruit in the dead of winter or microwaved a frozen burrito for dinner, you’ve taken advantage of a globe-spanning system that makes sure environmentally sensitive products can be safely stored and transported.

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