Ubiquitous Successful Bus: Hacking USB 2 Hubs

November 5, 2024 by 28 Comments

We’ve been recently looking into USB 2.0 – the ubiquitous point-to-point communications standard. USB 2 is completely different from USB 3, the blue-connector next-generation USB standard. For instance, USB 2 is a full-duplex pseudo-differential bus, and it’s not AC-coupled. This makes USB2 notoriously difficult to galvanically isolate, as opposed to USB 3.  On the other hand, USB 2 is a lot easier to incorporate into your projects. And perhaps the best way to do so is to implement a USB hub.

USB 2 hubs are, by now, omnipresent. it doesn’t cost much to add to your board, and you truly have tons of options. The standard option is 4-port hubs – one uplink port to your host, four downlink ports to your devices. If you only have two or three devices, you might be tempted to look for a hub IC with a lower amount of ports, but it’s not worth bothering – just use a 4-port chip, and stock up on them.

What about 7-port chips? You will see those every now and then – but take a close look at the datasheet. Some of them will be two 4-port chips inside a single package, with four of the ports bottlenecked compared to the three other ports – watch out! Desktop 7-port hubs are basically guaranteed to use two 4-port ICs, too, so, again, watch out for bottlenecks. lsusb -t will help you determine the hub’s structure in case you don’t want to crack its case open, thankfully.

Recommendations? I use SL2.1 chips – they’re available in an SO16 package, very unproblematic, to-the-point pinout and easily hand-solderable. CH334 is a close contender, but watch out because there are different variants of this chip that differ by both package and pinout, so if you’re buying a chip with a certain letter, you will want to stick to it. Not just that, be careful – different variants run out at different rates, so if you lock yourself into a CH334 variant, consider stocking up on it. Continue reading “Ubiquitous Successful Bus: Hacking USB 2 Hubs” →

The Hardware pipeline consists of three parts: antenna, signal conditioners, and computer. The solid lines indicate LMR-400 cable (low loss microwave coax), whereas the dotted line represents USB 3.0. (Credit: Jack Phelps)

Tracking Hydrogen In Space With A Home Radio Telescope For 21 Cm Emissions

November 5, 2024 by 7 Comments

What do you get when you put a one-meter parabolic dish, an SDR, a Raspberry Pi, and an H1-LNA for 21 cm emissions together? The answer is: a radio telescope that can track hydrogen in the Milky Way as well as the velocities of hydrogen clouds via their Doppler shifts, according to a paper by [Jack Phelps] titled “Galactic Neutral Hydrogen Structures Spectroscopy and Kinematics: Designing a Home Radio Telescope for 21 cm Emission“.

The hardware pipeline consists of three parts: antenna, signal conditioners, and computer, as per the above graphic by [Jack Phelps]. The solid lines are low-loss microwave coax LMR-400 cable, and the dotted line represents USB 3.0 between the RTL-SDR and Raspberry Pi 4 system. This Raspberry Pi 4 runs a pre-made OS image (NsfSdr) by [Dr. Glenn Langston] at the National Science Foundation, which contains scripts for hydrogen line observation, calibration and data processing.

After calibration, the findings were verified using publicly available data, and the setup could be used to detect hydrogen by pointing the antenna at the intended target in space. Although a one-meter parabolic dish isn’t going to give you the most sensitivity, it’s still pretty rad that using effectively all off-the-shelf components and freely available software, you too can have your own radio telescope.

Flirting With Kessler: Why Space Debris Physics Make It Such An Orbital Pain

November 5, 2024 by 37 Comments

Picture in your mind a big parking lot with 131 million cars on it. Now imagine that they are spread out over the entire Earth’s inhabited areas. Although still a large number, it is absolutely dwarfed by the approximately 1.47 billion cars registered and in use today, with room to spare for houses, parks and much more. The 131 million represents the total number of known and estimated space debris objects in Earth orbit sized 1 mm and up, as per the European Space Agency. This comes on top of the approximately 13,200 satellites still in Earth orbit of which 10,200 are still functional.

Now imagine that most of these 131 million cars of earlier are sized 10 cm or smaller. Spaced out across the Earth’s entire surface you’d not be able to see more than at most one. Above the Earth’s surface there are many orbital planes and no pesky oceans to prevent millimeter and centimeter-sized cars from being spaced out there. This gives a rough idea of just how incredibly empty Earth’s orbital planes are and why from the International Space Station you rarely notice any such space debris until a small bit slams into a solar panel or something equally not amusing.

Cleaning up space debris seems rather unnecessary in this perspective, except that even the tiniest chunk travels at orbital velocities of multiple kilometers per second with kinetic energy to spare. Hence your task: to chase down sub-10 cm debris in hundreds of kilometers of mostly empty orbital planes as it zips along with destructive intent. Surely this cannot be so difficult with lasers on the ISS or something?

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AI Not Needed For Hackaday Projects

November 5, 2024 by 19 Comments

It was Supercon this weekend, and Hackaday staffers made their way to Pasadena for what was by all accounts an excellent event. Now they’re all on their way home on red-eye flights and far from their benches, so spare a thought for the lonely editor holding the fort while they’ve been having fun. The supply of cool hacks for your entertainment must continue, so what’s to be done? Fortunately Hackaday writer [Anne Ogborn] has the answer, in the form of an automated Hackaday article generator.

We once had a commenter make a withering insult that one of our contributors’ writing styles looked like the work of an AI driven bot, a sentence that the writer in question treasures enough to have incorporated in their Hackaday email signature. [Anne] is a data scientist and Prolog programmer by trade so knows a bit about AI, and she has no need for such frippery. Instead she’s made a deck of cards each marked with a common theme among the work featured here, and generating new article titles is a simple case of drawing cards from the pack and assembling the resulting sentence.

The result is both amusing and we think, uncannily on the mark. Who wouldn’t want an ESP8266 powered cardboard drone? We think it will make a valuable addition to the Hackaday armoury, to be brought out on days such as the first of April, when there’s always an unexpected shortage of hacks. Video below the break.

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Flaming Power Wheels Skeleton Wins Halloween

November 5, 2024 by 48 Comments

When the project description starts with the sentence “I use an RC remote and receiver, an esp32, high-current motor drivers, servos, an FPV camera, and a little propane”, you know that this is one which deserves a second look. And so [gearscodeandfire]’s Halloween project caught our eye. It’s a pink Power Wheels jeep driven by a skeletal rider, and the best part is that the whole thing is remote controlled down to a pan-and-tilt skull, a first-person video feed, and even real flames.

At its heart is an ESP32 with a set of motor controllers and relays to do the heavy lifting. The controller is a standard radio remote controller, and the first-person view is an analogue feed as you’d find on a drone. The skeleton is given a child-like appearance by discarding the original adult-proportioned plastic skull and replacing it with a much larger item. The thought that plastic Halloween skulls are available in a range of standard sizes and can be considered as a part in their own right is something we find amusing. The propane burner is supplied from a small cylinder via a solenoid valve, and ignited with the spark from a high-voltage transformer.

The result, we think, wins Halloween hands down. Twelve-foot skeletons are SO 2023!

The video is below the break.

Continue reading “Flaming Power Wheels Skeleton Wins Halloween” →

An image of a dark mode Linux desktop environment. A white iTunes window stands out in a virtualized Windows 10 environment. Two iPod games, "Phase" and "Texas Hold 'Em" are visible in the "iPod Games" section of the library.

IPod Clickwheel Games Preservation Project

November 4, 2024 by No comments

The iPod once reigned supreme in the realm of portable music. Hackers are now working on preserving one of its less lauded functions — gaming. [via Ars Technica]

The run of 54 titles from 2006-2009 may not have made the iPod a handheld gaming success, but many still have fond memories of playing games on the devices. Unfortunately, Apple’s Fairplay DRM has made it nearly impossible to get those games back unless you happened to backup your library since those games can’t be downloaded again and are tied to both the account and iTunes installation that originally purchased the game.

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Humble Television Tubes Make An FM Regenerative Radio

November 4, 2024 by 10 Comments

The regenerative radio is long-ago superseded in commercial receivers, but it remains a common project for electronics or radio enthusiasts seeking to make a simple receiver. It’s most often seen for AM band receivers or perhaps shortwave ham band ones, but it’s a circuit which also works at much higher frequencies. [Perian Marcel] has done just this, with a regenerative receiver for the FM broadcast band.

The principle of a regenerative receiver is that it takes a tuned radio frequency receiver with a wide bandwidth and poor performance, and applies feedback to the point at which the circuit is almost but not quite oscillating. This has the effect of hugely increasing the “Q”, or quality factor of the receiver, giving it much more sensitivity and a narrow bandwidth. They’re tricky to tune but they can give reasonable performance, and they will happily slope-demodulate an FM transmission.

This one uses two tubes from consumer grade TV receivers, the “P” at the start of the part number being the giveaway for a 300mA series heater chain. The RF triode-pentode isn’t a radio part at all, instead it’s a mundane TV field oscillator part pushed into service at higher frequencies, while the other triode-pentode serves as an audio amplifier. The original circuit from which this one is adapted is available online, All in all it’s a neat project, and a reminder that exotic parts aren’t always necessary at higher frequencies. The video is below the break.

Continue reading “Humble Television Tubes Make An FM Regenerative Radio” →