A Treasure Trove In An English Field

June 3, 2024 by Jenny List 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 I saw someone snag an audio effects unit that may or may not work, and there are PC expansion cards and outdated memory modules aplenty.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 Mains cables, VGA cables, and outdated computer books.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” →

What Parts Should You Desolder?

November 5, 2023 by Jenny List 28 Comments

A rite of passage for a young electronics enthusiast used to be collecting an array of surplus boards from whatever could be found, and using them as sources of parts to desolder. It was possible with a bit of work and searching to build all manner of electronic projects without spending much at all. Many hardware hackers know their way around consumer electronics from the decade before their teenage years as a result. Secondhand components can still be used, but the type of components to be found has changed, as well as those needed. [ElectricMonkeyBrain] takes a look, and asks “What should you desolder?”.

As a general rule, he lands on the premise that it’s worth hanging on to the expensive stuff rather than the cheap stuff. Large capacitors, power semiconductors, and inductors aren’t cheap at all, and in the case of the inductors they can yield both ferrite parts and enameled wire for rewinding to suit. We’re surprised that he advocates holding on to electrolytic capacitors as a kit of many values is now pretty cheap, but it’s understandable that if you lack the part and it’s there on a motherboard in front of you, it’s worth desoldering. Finally, he discusses cases, something we’ve been tempted by a few times more than we’d like to mention.

In a world of easy online ordering, it’s useful to be reminded that sometimes there’s still space for salvaged parts, after all, no delivery service is as quick as reaching under your bench for an old ATX power supply to raid. As always though, don’t amass too much of it.

Continue reading “What Parts Should You Desolder?” →

A Lot Of Effort For A Pi Laptop

April 13, 2021 by Bryan Cockfield 7 Comments

Building a Raspberry Pi laptop is not that uncommon. In fact, just a few clicks from any of the major electronics suppliers will have the parts needed for such a project speeding on their way to your house in no time at all. But [joekutz] holds the uncontroversial belief that the value in these parts has somewhat diminishing returns, so he struck out to build his own Pi laptop with a €4 DVD player screen and a whole lot of circuit wizardry to make his parts bin laptop work.

The major hurdle that he needed to overcome was how to power both the display and the Pi with the two small battery banks he had on hand. Getting 5V for the Pi was easy enough, but the display requires 8V so he added one lithium ion battery in series (with its own fuse) in order to reach the required voltage. This does make charging slightly difficult but he also has a unique four-pole break-before-make switch on hand which doesn’t exactly simplify things, but it does make the project function without the risk of short-circuiting any of the batteries he used.

The project also makes use of an interesting custom circuit which provides low voltage protection for that one lonely lithium battery as well. All in all it’s a master course in using some quality circuit-building skills and electrical theory to make do with on-hand parts (and some 3D printing) rather than simply buying one’s way out of a problem. And the end result is something that’s great for anything from watching movies to playing some retro games.

Continue reading “A Lot Of Effort For A Pi Laptop” →

Spare Parts Express

October 17, 2020 by Elliot Williams 33 Comments

I’ve got spare parts, and I cannot lie.

This week I’m sending out two care packages to friends and coworkers because I’ve got too many hackables on hand, and not enough time to hack them all. One is a funky keyboard, and the other is an FPGA dev board, but that’s not the point. The point is that the world is too interesting, and many of us have more projects piled up in the to-do box, with associated gear, than we’ll ever have time to complete.

Back in the before-times, we would meet up, talk about our ongoing hacks, and invariably someone would say “oh you need an X, I’ve got half a box of them” and send you one. Or maybe you’d be the one with the extra widgets on hand. I know I’ve happily been in both positions.

Either way, it’s a win for the giver, who gets to take a widget off the widget pile, for the receiver, who doesn’t have to go to the widget store, and for the environment, which has to produce fewer widgets. (My apologies to the widget manufacturers and middlemen.)

This reminded me of Lenore Edman and Windell Oskay’s Great Internet Migratory Box Of Electronics Junk back in the late aughts. Trolling through the wiki was like a trip down memory lane. This box visited my old hackerspace, and then ended up with Bunnie Huang. Good times, good people, good hacker junk! And then there’s our own Brian Benchoff’s Travelling Hacker Box and spinoffs.

These are great and fun projects, but they all end up foundering in one respect: to make sense, the value of goods taken and received has to exceed the cost of the postage, and if you’re only interested in a few things in any given box, that’s a lot of dead weight adding to the shipping cost.

So I was trying to brainstorm a better solution. Some kind of centralized pinboard, where the “have too many h-bridge drivers” folks can hook up with the “need an h-bridge” people? Or is this ad-hoc social network that we already have working out well enough?

What do you think? How can we get the goods to those who want to work on them?

Ask Hackaday: How Do You Keep The 3D Printer From Becoming EWaste

January 2, 2020 by Jenny List 93 Comments

One thing we sometimes forget in our community is that many of the tecniques and machines that we take for granted are still something close to black magic for many outsiders. Here’s a tip: leave a 3D printer running next time you take a group of visitors round a hackerspace, and watch their reaction as a Benchy slowly emerges from the moving extruder. To us it’s part of the scenery, but to them it’s impossibly futuristic and their minds are blown.

Just because something says it's a Prusa i3, doesn't mean it is a Prusa i3. — Just because something *says* it’s a Prusa i3, doesn’t mean it is a Prusa i3.

Nearly 15 years after the dawn of the RepRap project we have seen a huge advancement in the capabilities of affordable 3D printers, and now a relatively low three-figure sum will secure a machine from China that will churn out prints whose quality would amaze those early builders. We’ve reached the point in our community at which many people are on their third or fourth printer, and this has brought with it an unexpected side-effect. Where once a hackerspace might have had a single highly prized 3D printer, now it’s not unusual to find a pile of surplus older printers on a shelf. My hackerspaces both have several, and it’s a sight I’ve frequently seen on my travels around others. Perhaps it’s a sign of a technology maturing when it becomes ewaste, and thus it seems affordable 3D printing has matured. Continue reading “Ask Hackaday: How Do You Keep The 3D Printer From Becoming EWaste” →

Racing Simulator Built From Scrapheap Finds

November 24, 2017 by Tom Nardi 13 Comments

Paradise means something different for everyone, it could be a sitting by a fire on a rainy night or lying on a sun-kissed beach. But for us, and makers like [liltreat4you], it’s a well stocked scrap pile out behind the house. After buying a racing wheel and pedals for his Xbox, he took a trip out to his little slice of paradise and found nearly all the hardware he needed to build a professional looking race simulator. According to his breakdown, most of the money he spent on this build ended up going into that sweet red paint job and the speed-enhancing stickers.

Everything the light touches is our kingdom.

Not all of us are as lucky as [liltreat4you], and we probably won’t just happen upon a driver’s seat out of a Mazda, or a bunch of perfectly bent metal pipes from an old trampoline out on the back forty. But trolling Craigslist or cruising around for flea markets can still get you parts like these for cheap, so try not to be too discouraged if your backyard isn’t quite as well stocked.

Once he had the metal pipes and seat from the car, the rest of the build came together pretty quickly. After building an oval out of his salvaged pipes, he attached the seat and the arms that would eventually hold the steering wheel and display. A plate was also added at the bottom for the pedals to sit on. By using long bolts, [liltreat4you] was even able to add a degree of adjustment to the wheel position. Being that he got his seat out of a real car, there’s the usual adjustment you’d expect there as well.

Speaking of which, [liltreat4you] casually mentions that you should disconnect the battery of the donor vehicle before taking out the seat, as it’s possible that the removal of the seat or the disconnection of the seat harness can cause the airbags to deploy. We can neither confirm nor deny this, but it’s probably safe advice to follow.

The purists out there may claim that what [liltreat4you] has put together doesn’t quite meet the definition of simulator in its current form. But with the addition of some instrumentation and just a bit of physical feedback, he’ll be well on his way to the complete driving experience.