Teardown: Nihon Kenko Magnetic Wave Tester

April 15, 2019 by Tom Nardi 35 Comments

You never know what kind of wonders you’ll find on eBay, especially when you have a bunch of alerts configured to go off when weird electronic devices pop up. You may even find yourself bidding on something despite not being entirely sure what it is. Perhaps you’re a collector of unusual gadgets, or maybe it’s because you’ve committed to doing monthly teardowns for the hacker blog you work for. In any event, you sometimes find yourself in possession of an oddball device that requires closer inspection.

Case in point, this “Magnetic Wave Tester” from everyone’s favorite purveyor of high-end electronics, Nihon Kenko Zoushin Kenkyukai Corporation. The eBay listing said the device came from an estate sale and the seller didn’t know much about it, but with just a visual inspection we can make some educated guesses. When a strong enough magnetic field is present, the top section on the device will presumably blink or light up. As it has no obvious method of sensitivity adjustment or even a display to show specific values, it appears the unit must operate like an electromagnetic canary in a coal mine: if it goes off, assume the worst.

If you’re wondering what the possible use for such a gadget is, you’re not the only one. I wasn’t able to find much information about this device online, but the few mentions I found didn’t exactly fill me with confidence. It seems two groups of people are interested in this type of “Magnetic Wave Tester”: people who believe strong magnetic fields have some homeopathic properties, or those who think it will allow them to converse with ghosts. In both cases, these aren’t the kind of users who want to see a microtesla readout; they want a bright blinking light to show their friends.

So without further ado, let’s align our chakras, consult with the spirits, and see what your money gets you when you purchase a pocket-sized hokum detector.

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A Robust ESP8266 RFID Access Control System

April 15, 2019 by Tom Nardi 19 Comments

By now we’ve seen plenty of projects that use an ESP8266 as a form of rudimentary access control: tap a button on your smartphone, and the door to your apartment unlocks. With the power and flexibility of the ESP, it’s a very easy project to pull off with minimal additional hardware. But what about if you want to get a little more serious, and need to support many users?

Rather than reinvent the wheel, you might want to check out the extremely impressive ESP-RFID project. It’s still based on the ESP8266 we all know and love, but it combines the diminutive WiFi-enabled microcontroller with a nice custom PCB and some exceptionally slick software to create a very professional access control system without breaking the bank. As the name implies, the system is geared towards RFID authentication and supports readers such as the MFRC522, PN532 RFID, or RDM6300. Add in a stack of Mifare Classic 1KB cards, and your hackerspace is well on the way to getting a new door control system.

The official hardware for ESP-RFID can be purchased through Tindie with or without an installed ESP-12F module, but as it’s a fully open source project, you’re also free to build your own version if you’d like. In either event, the board allows you to easily connect the ESP up to your RFID reader of choice, as well as door sensors and of course the door locks themselves.

On the software side of things, ESP-RFID should be able to handle about 1000 unique users and their RFID cards before the relatively limited RAM and storage of the ESP catches up with it. But if you’ve got that many people coming and going in your hackerspace, it might be time to update your systems to begin with. Incidentally, the project makes no guarantees about the security of the ESP-RFID code, and says that the system shouldn’t be used for secure locations. That said, you can run ESP-RFID without an Internet connection to reduce your attack surface, at the cost of losing NTP time synchronization.

If you’re not managing a few hundred users and their RFID cards, one of the more simplistic ESP8266 door locks might be more your speed. We’ve also seen similar tricks pulled off with the Particle Photon, in case you’ve got one of those rattling around the parts bin.

Mini Flickering Torch Effect Uses Neither Wires Nor Solder

April 15, 2019 by Donald Papp 8 Comments

[ROBAGON] makes miniature, 3D-printable gaming terrain and features like these stone pillars with flickering torch. His model isn’t free to download (though it’s under $2 at the time of writing), but the part that impressed us was his clever way of using electric tea lights to create a flickering torch effect without needing any soldering or wiring whatsoever.

His solution was to make the base of the pillar large enough to fit an electric tea light, which uses a flickering LED to simulate a candle flame. The molded plastic “flame” is removed from the tea light and placed in the torch sconce, while the tea light itself goes into the base. A short segment of clear acrylic rod is used as a light pipe, running from the tea light’s LED to the base of the torch.

It’s a simple, effective, and economical solution that doesn’t require running or soldering a single wire and you can see it work in the brief video embedded below. Now all that’s missing for those Dungeons & Dragons sessions is this custom calculator.

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Replicating 1970s LED Displays

April 14, 2019 by Brian Benchoff 13 Comments

In 1971, Texas Instruments released something no one else had ever seen before. The TIL305 was an alphanumeric display, powered by LEDs. Sure, the technology of the early 70s meant the LEDs weren’t very bright, and the displays were expensive, but if you want a display that’s simply classic, and relatively low-power, you won’t be able to do better than a vintage alphanumeric LED display.

As you would expect, new old stock TIL305s are still pricey, and now everybody has access to cheap PCB manufacturing capabilities and really small LEDs. The DIYTIL305 is an attempt to replicate the vintage stuff, and it looks great.

The vintage, TI-made TIL305 is a printed circuit board that clips into a DIP-14 socket. The LED array is 5×7 pixels, with an extra dot for a decimal point, set on a 0.05″ grid, and a translucent red diffuser. A PCB is easy, and with 0201 LEDs you can get the LED pitch you need. Turning a PCB into a DIP-14 only requires a few machine pin headers, and for the diffuser, this project is using laser cut cast acrylic. It’s simple if you have a pick and place machine or a steady hand, and assembly is a snap.

The final DIYTIL305 boards are being tested right now, but so far the results are great. With the right code on a microcontroller, these displays will blink through the digits 0 through 9, and the alphabet is just a little more code. Since this project is using 0201 LEDs, it also means green, white, blue, orange, and yellow displays are possible, something no one could have dreamed of in 1971.

Only 90s Kids Want Heelys Made From Pallet Wood

April 14, 2019 by Brian Benchoff 7 Comments

The kids are simply cooler than you. While you’re walking around using your feet like an animal, kids have shoes with wheels in their heels. These are called Heelys, and here’s how you make wooden clogs, with wheels in the heels, out of pallet wood. If you have to ask why, you’ll never know.

This build started off with a fairly large maple log, which would be the traditional way to build clogs. After taking this log to the bandsaw and looking inside, [Jackman] found a bit of spalting, or arguably aesthetically pleasing fungal growth. Whether the spalting would look good or not is a matter for debate, but either way [Jackman] decided to change plans and moved over to creating pallet wood clogs. A word of warning about pallet wood: you shouldn’t make anything out of wood from discarded pallets unless you know what you’re doing, and even if you do know what you’re doing there will be someone in the comments telling you that you shouldn’t use wood from discarded pallets. You can check out the comments to this article to verify this fact.

The construction of the clogs started with a few pieces of one inch stock glued up into a gigantic block, then several pieces of half inch stock resawn into quarter inch stock and laminated onto the sole of the clog. This was then shaped using a variety of tools from Arbortech; of note, we have the Turbo Plane, a wood shaping tool for a grinder that sounds more dangerous than it is, the Turbo Shaft, a plunge router or mortiser-sort-of-thing for a grinder that’s much cooler than it sounds, and the Power Chisel, something we can’t even believe exists and hold on here’s all our money.

These tools couldn’t get all the way into the toe of the clog, which meant [Jackman] had to saw down the middle and hollow everything out that way, but this did give him a nice flat surface on the inside to install the Heely wheels. This turns the clogs into something nine-year-olds simultaneously desire and don’t appreciate, because they’re kids.

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Hackaday Links: April 14, 2019

April 14, 2019 by Brian Benchoff 10 Comments

Look at this prototype Apple smartphone from 1993! For a long time, Apple has been in the phone game, with many failed attempts to combine a laptop screen with a phone. The most noteworthy attempt would be the Snow White phone designed around 1982, but this didn’t go to market. Apple tried again in 1993 with the Walt phone, and now we have someone willing to tear open a prototype. The guts are apparently a contemporary PowerBook (something along the lines of a PowerBook 140 or 170), which means you’re probably looking at a 68030 processor and between 2 and 8 Megabytes of RAM. The rest of the hardware looks fairly standard; SCSI drive and a fax/modem adapter. The software, though, is Hypercard. Here’s the video of the thing booting, and it’s an interesting look at the ‘computer appliance’ trend from the late 90s; once again, Apple was ahead of the curve.

Disregarding any of the implications of geopolitics of the time (as we do with these sorts of things), the Horten Ho 299 was a jet-powered flying wing that first flew in 1944. It’s in the Smithsonian now (and on display, at Dulles) and is a weird, strange, but incredibly interesting footnote in aviation history (because of the implications of geopolitics at the time, but again, we’re not going to get into that). Now the Horten flies again. A company unrelated to Herr Horten has recreated the one-man flying wing. It’s a real experimental aircraft now. Sure, it’s a piston-powered airplane, but if you want to fly something that looks even cooler than something Burt Rutan grew out of fiberglass, this is what you want.

For the past few months, Hackster has been running a BadgeLove contest, now the entries are closed and the winners are here. The Badge Of All Badges is a contactless/NFC badge, the blinkiest has some awesome documentation, and the best art is directly from Pokemon Yellow.

Vinyl has made a comeback, and so far we’ve been accepting of that. The album art is better when it’s bigger, and a record is more of an experience than popping in a CD or streaming some music. There’s a reason your favorite Beatles song is the B-side of Abbey Road. What’s the next frontier of high-end audio? Reel to reel, and Thorens is making a new tape machine. First off: it costs thirteen thousand dollars. It’s a quarter inch tape, and yeah, you can totally find a machine that will play quarter inch tapes for far less money.

Due to my vocation, I am awash in press releases every day. This doesn’t give me access to technology trends, far from it. It gives me access to marketing trends. Want to know about the fog, or ‘the cloud at ground level’? The first time anyone with two brain cells saw that phrase was in an unsolicited email, and it’s in my inbox. The latest trend — and I assure you this didn’t happen last year — is advertising explicit targeted towards April 20th. 4/20 is now mainstream, because marketing decided you can sell stuff to stoners. I’m looking at an email right now that starts with, “Hi Brian, With 4/20 fast approaching I thought you’d be interested….” There’s another one for vapes. This year, 4/20 has become a consumer holiday, so this year be on the lookout for the new, innovative ways you’re being sold stuff.

A Peek Inside A Typical British Residential Power Panel

April 14, 2019 by Dan Maloney 43 Comments

No matter what field you’re in, it’s interesting and instructive to find out how others practice it. That’s especially true with electrical distribution systems, where standards and practices differ from country to country and even between regions. This tour of a typical British residential electrical panel is a great example of the different ways that the same engineering problems can be solved, and the compromises that always attend any design.

We’re used to seeing [Big Clive] tearing interesting devices to bits, but rest assured that this electrical panel remains largely intact as it gives up its secrets. Compared to the distribution panels and circuit breakers common in North American residential construction, the British consumer unit is a marvel of neatness and simplicity. True, the unit on display hasn’t been put into service yet, and things will no doubt change once an electrician is through with it, but the fact that everything is DIN rail mounted is pretty cool. [Clive] explains a few of the quirks of the panel, such as the fact that what looks like a main breaker is in fact just an isolation switch, and that there are a pair of residual current devices (RCDs), which we call ground-fault circuit interrupters (GFCIs) in North America, that also don’t act as circuit breakers, despite appearances. A stout bus bar is provided to link the RCDs to adjacent circuit breakers, forming two groups that are separately protected from ground faults.

[Clive] notes with dismay that the lugs of the bus bar can actually be inserted behind the rising clamp terminal on the breaker, resulting in poor connections and overheating. Still, we wouldn’t mind some of these concepts brought to panels in North America, which we covered a bit in a discussion on circuit protection a while back.

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