VCF Swap Meet Takes Step Back To Move Forward

April 28, 2021 by Tom Nardi 44 Comments

When computers were the sort of thing you ordered from a catalog and soldered together in your garage, swap meets were an invaluable way of exchanging not just hardware and software, but information. As computers became more mainstream and readily available, the social aspect of these events started to take center stage. Once online retail started really picking up steam, it was clear the age of the so-called “computer show” was coming to a close. Why wait months to sell your old hardware at the next swap when you could put it on eBay from the comfort of your own home?

Of course, like-minded computer users never stopped getting together to exchange ideas. They just called these meets something different. By the 2000s, the vestigial remnants of old school computer swap meets could be found in the vendor rooms of hacker cons. The Vintage Computer Festival (VCF) maintained a small consignment area where attendees could unload their surplus gear, but it wasn’t the real draw of the event. Attendees came for the workshops, the talks, and the chance to hang out with people who were passionate about the same things they were.

Consignment goods at VCF East XIII in 2018.

Then came COVID-19. For more than a year we’ve been forced to cancel major events, suspend local meetups, and in general, avoid one another. Some of the conventions were revamped and presented virtually, and a few of them actually ended up providing a unique and enjoyable experience, but it still wasn’t the same. If you could really capture the heart and soul of these events with a video stream and a chat room, we would’ve done it already.

But this past weekend, the folks behind VCF East tried something a little different. As indoor gatherings are still strongly discouraged by New Jersey’s stringent COVID restrictions, they decided to hold a computer swap meet in the large parking lot adjacent to the InfoAge Science and History Museum. There were no formal talks or presentations, but you could at least get within speaking distance of like-minded folks again in an environment were everyone felt comfortable.

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How Best To Get Your Project On Hackaday

April 27, 2021 by Lewin Day 34 Comments

We’re blessed to have such a great community at Hackaday. Our tipline often overfloweth with all manner of projects and builds of all stripes. We see it all here, from beginners just starting out with their first Arduino to diehard hackers executing daringly complex builds in their downtime, and everything in between.

If you’re sitting there in the grandstands, watching in awe, you might wonder what it takes to grace these hallowed black pages. In life, nothing is guaranteed, but I’ve been specially authorised to share with you a few tips that can maximise your chances of seeing your project on Hackaday.

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Ask Hackaday: Why Make Modular Hardware?

April 27, 2021 by Adam Zeloof 33 Comments

In the movies, everything is modular. Some big gun fell off the spaceship when it crashed? Good thing you can just pick it up and fire it as-is (looking at you, Guardians of the Galaxy 2). Hyperdrive dead? No problem, because in the Star Wars universe you can just drop a new one in and be on your way.

Of course, things just aren’t that simple in the real world. Most systems, be they spaceships or cell phones, are enormously complicated and contain hundreds or thousands of interconnected parts. If the camera in my Samsung phone breaks, I can’t exactly steal the one from my girlfriend’s iPhone. They’re simply not interchangeable because the systems were designed differently. Even if we had the same phone and the cameras were interchangeable, they wouldn’t be easy to swap. We’d have to crack open the phones and carefully perform the switch. Speaking of switches, the Nintendo Switch is a good counterexample here. Joycon break? Just buy a new one and pop it on.

What if more products were like the Nintendo Switch? Is its modularity just the tip of the iceberg?

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Review: Sequre SQ-D60 Temperature Controlled Soldering Iron

April 27, 2021 by Jenny List 38 Comments

Over the past few years a new class of soldering iron has arisen: a temperature controlled iron no longer tied to a bulky mains-powered base station, but using low-voltage DC power and with all electronics concealed in a svelte handle. First came the Miniware TS100, and then many more, with slightly different feature sets and at varying price points. We’ve reviewed a few of them over the years, and today we have the most recent contender in the Sequre SQ-D60. It follows the formula closely, but costs only £20 (about $26). This price puts it in an attractive budget category, and its USB-C power option makes it forward-looking over models with barrel jacks. Description over, it’s time to plug it in and put it through its paces.

What’s In The Box?

That's a lot of extra bits for a budget iron! — That’s a lot of extra bits for a budget iron!

In the box, aside from the handle containing the electronics, were a surprisingly comprehensive array of parts and accessories. The handle itself is similarly-sized to its competitors, being only slightly longer than that of Pine64’s Pinecil. The tip supplied was unexpectedly a slanted chisel, so I may have managed to order incorrectly, though since it shares the same tip design as both the TS100 and the Pinecil I have plenty of alternative tips should I need one. Otherwise there was a little bag of hex screws along with a key and a driver for them, a little stand with a sponge, a set of Sequre stickers, a USB-C to barrel jack cable, and a barrel jack-to-XT60 connector for use with LiPo battery packs. These last two cables are a particularly useful addition.

At first sight the tip doesn’t seem to have any means of being fixed into its socket, but a closer inspection reveals that there is a hex screw hiding underneath a silicone finger sleeve that holds it securely when tightened. The handle has a simple enough interface, with just two buttons and a 3-digit, 7-segment display. Powering it up from a 45 W USB-PD power supply, and it heats up to 300 °C in around ten seconds after pressing one of the buttons. My usual soldering temperature is 360 °C, and it has an interface involving long presses of one of the buttons before they become up and down buttons to select the temperature. In prolonged use the handle doesn’t become noticeably warm, and aside from a slight new-electronics-getting-hot smell there was no immediate concern that it might release magic smoke. Continue reading “Review: Sequre SQ-D60 Temperature Controlled Soldering Iron” →

Linux Fu: A Little Bit Of (Network) History Repeating Itself

April 26, 2021 by Al Williams 5 Comments

These days, embedded systems often have networks and that can make them significantly more complex. Networks are usually pretty nondeterministic and there are a variety of oddball conditions. For example, when your public-access pick and place machine gets written up on Hackaday and you suddenly get a 50X surge in traffic, how does your network stack handle it? While there’s no silver bullet for network testing, there are some tricks that can make it easier and one of those is the tcpreplay utilities that allow you to record complex network traffic and then play it back in a variety of ways. This has many benefits, especially if you manage to capture that one thing that triggers bad behavior sporadically. Being able to play it back on demand can speed up diagnostics considerably.

General Idea

You probably know that tcpdump allows you to grab packet captures from a network interface and save them to a file. If you prefer a GUI, you probably use Wireshark, which uses the same underlying library (libpcap) to grab the data. In fact, you can capture data using tcpdump and look at it with Wireshark, although there are other tools like tcptrace or Ngrep that can work with the output, also.

While the output of the command can be a little cryptic without tool support, a program called tcpreplay can take that data and feed it back in a variety of ways. Of course, you can modify the file first — there are tools to make that easier and — if you need to — you can craft your own network traffic by hand or using one of a variety of tools. This process is often called “packet crafting.”

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Hackaday Links: April 25, 2021

April 25, 2021 by Dan Maloney 14 Comments

There’s much news from the Jezero Crater on Mars this week, and all of it was good. Not only did the Ingenuity helicopter make history by making the first powered, controlled flight of an aircraft on another planet, it made a second longer, more complex flight just a couple of days later. This time, the autonomous rotorwing craft flew to a higher altitude than the maiden flight, hovered for a bit longer, and made a lateral move before landing safely again on the surface. Three more flights of increasing complexity (and risk) are scheduled over the next two weeks, with the next set to happen early Sunday morning. I have to admit that even though the Ingenuity tech demonstration seemed a little like a publicity stunt when I first heard about it, especially when compared to the Perseverance’s main mission of searching for evidence of life on Mars, the Ingenuity team’s successes have made a believer out of me.

Speaking of technology demonstrations, NASA fired up the MOXIE experiment aboard Perseverance for the first time. Intended to explore the possibility of producing oxygen from the thin carbon dioxide-rich Martian atmosphere, the Mars Oxygen In-Situ Resource Utilization Experiment made about 5.4 grams of oxygen total at a rate of about 6 grams an hour. We detailed the technology MOXIE uses, called solid-oxide electrolysis, which depends on a scandium-stabilized zirconium oxide ceramic electrolyte to strip the oxygen from superheated carbon dioxide using an electric current. Should the technology prove itself over the planned total of ten MOXIE runs over the next few months, a scaled up version of the device could someday land on Mars and produce the estimated 55 metric tons of oxygen needed to fuel a return trip from a crewed mission.

By now we’ve all heard about the global semiconductor shortage, or perhaps felt the pinch ourselves while trying to procure parts for a build. It’s easy to count the crunch as yet another follow-on from the COVID-19 shutdowns and the logistics woes the pandemic begat, so one might have hope that with lockdowns easing up around the world, the shortage will soon be over as manufacturers ramp up production. But not so fast — it looks like the machines needed to make the chips are the latest victims of the shortage. According to Nikkei Asia, wire bonding machines, wafer dicers, and laser drilling machines are all in short supply, with orders for new machines booked out for a year. Like toilet paper this time last year, chip makers are hoarding machines, ordering 50 or 100 of them at a time, in the hopes of having enough to meet production goals. And when machines are available, travel restrictions are making it difficult to get on-site installation and support from factory reps. The bottom line — this isn’t over yet, not by a long shot.

We all know the Stack Overflow memes, and few of us who are being honest haven’t squirmed a bit when thinking about just how screwed we’d be without being able to copy a bit of code to get us past that rough part in a project. But just how often do people copy code from Stack Overflow? Quite a lot, actually, if SO’s analysis of the use of copy commands on their pages is to be believed. For two weeks, SO monitored the number of times the Ctrl-C (or Command-C, if that’s your jam) key combination was pressed. They toted up over 40 million copies, most often from the answers to questions and almost always from the code blocks within them. We suppose none of this is exactly unexpected — memes are memes for a reason, after all — but what we found surprising is that one in four visitors to Stack Overflow copied something within five minutes of loading a page. Being charitable, we’d say the speed with which coders accept someone else’s work is an indication that maybe they were almost at an answer themselves and just needed a little reminder. On the other hand, it could be a sign of separation driving them to get something working.

And finally, while we know we’ve recommended videos from Grady at Practical Engineering recently, we couldn’t help but plug another of his videos as a must-watch. This time, Grady tackles the Suez Canal blockage, and he presents it in the same dispassionate, informed way that he previously handled the engineering roots of the Texas blackouts. If you think the Ever Given grounding was just a case of poor seamanship, think again — Grady makes a compelling case for possible hydrodynamic causes of the incident, including “squatting” and the bank effect. He also speculates on the geotechnical forces that held the ship fast, in the process of which he helpfully introduces the concept of dilatancy and how it explains the way your feet seem to “dry out” a zone around them as you walk across the beach.

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Fail Of The Week: Mistaking Units For Values

April 24, 2021 by Jenny List 93 Comments

Usually when we post a Fail Of The Week, it’s a heroic tale of a project made with the best of intentions that somehow failed to hit its mark. The communicator that didn’t, or the 3D-printed linkage that pushed the boundaries of squirted plastic a little bit too far. But today we’re bringing you something from a source that should be above reproach, thanks to [Boldport] bringing us a Twitter conversation between [Stargirl] and [Ticktok] about a Texas Instruments datasheet.

The SN65220 is a suppressor chip for USB ports, designed to protect whatever the USB hardware is from voltage spikes. You probably have several of them without realising it, the tiny six-pin package nestling on the PCB next to the USB connector. Its data sheet reveals that it needs a resistor network between it and the USB device it protects, and it’s this that is the source of the fail.

There are two resistors, a 15kO and a 27O, 15k ohms, and 270 ohms, right? Looking more closely though, that 27O is not 270 with a zero, but 27O with a capital “O”, so in fact 27 ohms.

The symbol for resistance has for many decades been an uppercase Greek Omega, or Ω. It’s understood that sometimes a typeface doesn’t contain Greek letters, so there is a widely used convention of using an uppercase “R” to represent it, followed by a “K” for kilo-ohms, an “M” for mega-ohms, and so on. Thus a 270 ohm resistor will often be written as 270R, and 270 kilo-ohm one as 270K. In the case of a fractional value the convention is to put the fraction after the letter, so for example 2.7kilo-ohms becomes 2K7. For some reason the editor of the TI datasheet has taken it upon themselves to use an uppercase “O” to represent “Ohms”, leading to ambiguity over values below 1 kilo-ohm.

We can’t imagine an engineer would have made that choice so we’re looking towards their publishing department on this one, and meanwhile we wonder how many USB devices have gone to manufacture with a 270R resistor in their data path. After all, putting the wrong resistor in can affect any of us.