A Friendly Reminder That You Might Be In Danger

August 19, 2019 by Tom Nardi 5 Comments

Product recalls are one of those things that most people don’t pay attention to until things get really bad. If it’s serious enough for somebody to get hurt or even die, then the media will pick it up, but most of the time they simply pass by in silence. In fact, there’s a decent chance that you own a recalled product and don’t even know it. After all, it’s not like anyone is actually watching the latest product recalls in real-time.

Well actually, there might be one guy. [Andrew Kleindolph] has created a cute and cuddly gadget using CircuitPython on the Adafruit PyPortal to display the latest release from the United States Consumer Product Safety Commission (USCPSC). In a wonderfully ironic touch, the child’s unicorn boot that the device lives in is itself a recalled product; apparently kids could pull off the “horn” and choke on it.

The PyPortal is basically built for this kind of thing, allowing you to easily whip up a display that will scrape data from whatever online source you’re willing to write the code for. All [Andrew] had to do was pair it with a battery so the boot could go mobile occasionally (we’re told they’re made for walkin’), and design some 3D printed accoutrements such as a screen bezel and charging port.

As these recalls (thankfully) don’t come out quite so fast that you need it to update more than once or twice a week, it seems like this could also be an excellent application for an Internet-connected e-ink display.

3D Printed Fan Filter Takes Cues From Costume Scene

August 3, 2019 by Donald Papp 3 Comments

This custom fan filter created by [Kolomanschell] is a clever application of a technique used to create wearable 3D printed “fabrics”, which consist of printed objects embedded into a fine mesh like a nylon weave. The procedure itself is unchanged, but in this case it’s done not to embed 3D printed objects into a mesh, but to embed a mesh into a 3D printed object.

The basic idea is that a 3D print is started, then paused after a few layers. A fine fabric mesh (like tulle, commonly used for bridal veils) is then stretched taut across the print bed, and printing is resumed. If all goes well, the result is 3D printed elements embedded into a flexible, wearable sheet.

The beauty of this technique is that the 3D printer doesn’t need to be told a thing, because other than a pause and resume, the 3D print is nothing out of the ordinary. You don’t need to be shy about turning up the speed or layer height settings either, making this a relatively quick print. Cheap and accessible, this technique has gotten some traction in the costume and cosplay scene.

As [Kolomanschell] shows, the concept works great for creating bespoke filters, and the final result looks very professional. Don’t let the lack of a 3D model for your particular fan stop you from trying it for yourself, we’ve already shared a great resource for customizable fan covers. So if you’ve got a 3D printer and a bit of tulle, you have everything you need for a quick afternoon project.

Put Those IPad Displays To Work With This EDP Adapter

July 18, 2019 by Tom Nardi 37 Comments

Regardless of how you might feel about Apple and the ecosystem they’ve cultured over the years, you’ve got to give them some credit in the hardware department. Their “Retina” displays are a perfect example; when they brought the 2,048 by 1,536 panel to the iPad 3, the technology instantly became the envy of every tablet owner. But what if you want to use one of these gorgeous screens outside of Apple’s walled garden?

As it turns out, there are a number of options out there to use these screens on other devices, but [Arthur Jordan] wasn’t quite happy with any of them. So he did what any self respecting hacker would do, and built his own adapter for iPad 3 and 4 screens. Not that he did it completely in the dark; his design is based on the open source Adafruit Qualia driver, which in turn was based on research done by [Mike’s Mods]. A perfect example of the open source community at work.

The resulting board allows you to connect the Retina display from the iPad 3 or 4 to any device that features Embedded DisplayPort (eDP). Rather than put a dedicated port on his board, [Arthur] just left bare pads where you can solder up whatever interface method your particular gadget might use. In his case, he wanted to hook it up to an x86 UP Core SBC, so he even came up with a seperate adapter that breaks out that board’s diminutive display connector to something that can be soldered by hand.

So what’s different between the board [Arthur] developed and Adafruit’s Qualia? Primarily its been made smaller by deleting the DisplayPort connectors in favor of those bare pads, but he’s also dumped the backlight control hardware and 3.3V regulator that in his experience hasn’t been necessary with the eDP devices he’s worked with. So if space is a concern in your build, this version might be what you’re after.

We’ve seen other Retina display adapters in the past, and of course the iPad isn’t the only high-end device that’s had a screen good enough to reuse on its own. The lesson here is that if you put a must-have feature in your product, don’t be surprised when some hacker comes along and figures out how to liberate it for their own purposes.

High-Tech Alms Collection With The ESP32

July 17, 2019 by Tom Nardi 2 Comments

In an ideal world, shop space, tools, and components would be free. But until we get to that Star Trek utopia, hackerspaces will have to rely on donations from the community to help stay afloat. While asking for money, at least you can have some fun with it if you design and build an Internet-connected donation box.

Or at least that’s how [Goran Mahovlic] handled it for the Radiona hackerspace in Zagreb, Croatia. Not content with just cutting a slit in the top of a shoe box, he came up with a physical donation system that’s not only more informative for those donating, but more organized for those collecting the funds.

The key is a arcade-style programmable coin acceptor from SparkFun. When connected to a microcontroller, this allows the box to keep a running tally on how much money has been inserted. With the use of a RFM96 LoRa module, it can even report on the current haul while remaining mobile; perfect for when the hackerspace has events outside of their home base.

But counting quarters is hardly a task befitting a powerful microcontroller like the ESP32. So [Goran] gave the chip something to do in its spare time by adding a couple of buttons and an LCD. This allows the user to scroll through a list of various projects that are looking for donations, and decide which one they want to financially support. When the donation box counts how much money has been inserted, it records which project its been earmarked for.

Of course, if you’d rather the free market do its thing, we’ve seen this same coin acceptor used to build a locker-sized vending machine. Or if you’re feeling crafty, you could always try your hand at building one with cardboard.

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The Basics Of SCRs

July 14, 2019 by Al Williams 8 Comments

Although the silicon controlled rectifier or SCR has been around since 1957, it doesn’t get nearly the love an ordinary transistor does. That’s a shame because they are quite handy when it comes to controlling AC and DC voltages in things such as lamp dimmers, motor speed controllers, and even soldering iron temperature controllers. [Lewis Loflin] has a short video introduction that will help you get started with these devices.

One of the interesting properties of the device is that once you turn it on it will stay on until you do something specific to turn it back off — sort of, [Lewis] explains it in the video.

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Ditch The Switch: A Soft Latching Circuit Roundup

June 24, 2019 by Tom Nardi 32 Comments

For some of us, there are few sounds more satisfying than the deep resonant “thunk” of a high quality toggle switch slamming into position. There isn’t an overabundance of visceral experiences when working with electronics, so we like to savor them when we get the chance. But of course there’s no accounting for taste, and we suppose there are even situations where a heavy physical switch might not be the best solution. So what do you do?

Enter the latching power circuit, often referred to as a “soft” switch. [Chris Chimienti] has recently put together a fascinating video which walks the viewer through five different circuits which can be used to add one of these so-called soft power switches to your project. Each circuit is explained, diagramed, annotated, and eventually even demonstrated on a physical breadboard. The only thing you’ve got to do is pick which one you like the most.

There’s actually a number of very good reasons to abandon the classic toggle switch for one of these circuits. But the biggest one, somewhat counterintuitively, is cost. Even “cheap” toggle switches are likely to be one of the most expensive components in your bill of materials, especially at low volume. By comparison, the couple of transistors and a handful of passive components it will take to build out one of these latching circuits will only cost you a couple of cents.

Even if you aren’t in the market for a new way to turn off your projects, this roundup of circuits is a fantastic reminder of how powerful discrete components can be. In an age where most projects seem assembled from pre-fabbed modules, it’s occasionally refreshing to get back to basics.

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New Part Day: This $10 Rocking Single Board Computer Does Everything You Want

June 21, 2019 by Brian Benchoff 74 Comments

Single board computers are great, but what we really need are cheap single board computers. Running Linux on anything isn’t as good as running Linux on everything, and all that. To that end, here is the Rock Pi S, a $10 single board computer with Ethernet, WiFi, and it costs $10.

This one comes from the boffins at Radxa, already behind the footnote-worthy Rock Pi 4, a single board computer that appears to be heavily derived from the Raspberry Pi but with a 4 in the name so it’s obviously better. It also has 4 GeeBees of RAM, so it’s got that going for it too. Their latest product is the Rock Pi S, a board that seems as though it’s taking inspiration from the C.H.I.P.. The biggest selling point is of course the price: $10 for the version with 256MB of RAM and without WiFi or Bluetooth. Various other incarnations exist with permutations of 256MB or 512MB of RAM, and with or without WiFi and Bluetooth. The highest spec variant costs $16, but is sold out at the moment.

This tiny little single board computer fills a need in the marketplace; the Raspberry Pi Zero is cheap and small when it’s available, but sometimes you need Ethernet for various reasons and a real USB A port is great to have. We’re looking forward to the builds this tiny board enables and all the fantastic creations that will come from a community so very interested in single board computers.