Occasionally you run across a product that you just know is simply too good to be true. You might not know _why_, but you've got a hunch that what the bombastic phrasing on the package is telling you just doesn't quite align with reality. That's the feeling I got recently when I spotted the "LED intellibulb Battery Backup" bulb by Feit Electric. For around $12 USD at Home Depot, the box promises the purchaser will "Never be in the dark again", and that the bulb will continue to work normally for up to 3.5 hours when the power is out. If I could repurpose that to make a tiny UPS for a microcontroller project of my own, it could be even more useful.

Now an LED light bulb with a battery in the base isn't exactly rocket science, we can understand the product conceptually at a glance. But as they say, the devil is in the details. The box claims the bulb consumes 8.5 watts, but a battery with enough capacity to run such a load for 3.5 hours would be far too large to fit inside of a light bulb. Obviously there's more to the story.

On the side of the box, in the smallest font used on the whole package, we get our clue. The bulb drops down to 200 lumens when in battery backup mode, or roughly as bright as a cheap LED flashlight. Now things are starting to come together. Without even opening the device, we can be fairly sure it will contain two separate arrays of LEDs: one low set for battery, and a brighter set to run when the bulb has AC power.

Still, I tend to be of the opinion that anything less than $20 or so is worth cracking open to see what makes it tick. Even if the product itself is underwhelming, there's a chance the internal components could be useful or interesting. With that in mind, let's see what's inside a battery backup light bulb, and what we might be able to do with it.

DISASSEMBLY I fully expected to have the cut the bulb open, but was pleasantly surprised you can disassemble it non-destructively. Not that it was the intent during manufacturing, of course, but it's a nice side effect of the fact that some poor soul probably had to assemble these things by hand.

If you squeeze the frosted plastic dome, eventually the glue used to secure it will pop, and from there it just takes some light prying to release. Once the dome is off, you'll be presented with the LED array. Three screws around the outside of the LEDs will allow you to pull all the electronics out of the bulb. Two wires run down into the base, which unfortunately appears to be pressed into the plastic permanently. So to extract the electronics you either need to snip the wires or desolder them from the board.

LED ARRAY As expected, there are two concentric rings of LEDs in the array which turn on or off depending on whether the bulb is on AC or DC power. The inner ring of LEDs as well as the five in the center light up when on DC power, and when AC is available the outer LEDs come on. It's worth noting that the center LEDs don't get any brighter on AC versus DC, but that the outer LEDs are _much_ brighter than the inner.

This makes sense given the information on the box: if the total output of the bulb is 600 lumens, but only 200 lumens on battery power, we know that the outer LED ring must output roughly 400 lumens on its own.

The array looks reasonably well made, and is attached to a rather nice circular aluminum heatsink. While the wires aren't labeled, it isn't hard to figure out that the center wire is negative and the two outer wires correspond to the two LED rings. This module would be very easy to reuse in a project where you might want variable brightness without having to bother with PWM.

POWER SUPPLY The board should look pretty familiar if you've ever seen the inside of an LED bulb before. It's a double-sided PCB with a fairly simple layout: transformer and capacitors on the top side for AC to DC conversion, with the flip side featuring the brains of the operation. The white connector on the top side of the board connects to the 3.7V 2000mAh battery, which incidentally takes up most of the internal volume of the bulb.

THEORY OF OPERATION The thing to remember about this bulb is that it isn't like an emergency light; it doesn't just automatically turn on when the power is cut. It's a light bulb, after all, and it needs to turn off when you flip the switch or unscrew the bub.

Instead the bulb detects when power is lost in the circuit it's connected to. It does this by testing the resistance between its AC terminals when it loses power. If there is "infinite" resistance, it knows that it has been switched off or unplugged.

Interestingly, the circuitry in the bulb sensitive enough that if you hold the bulb in your bare hand it will see it as an unpowered circuit and light up. Depending on your sense of humor, that might be worth the $12 alone.

I wanted to clarify how the bulb works, because I think it opens up some interesting possibilities for reusing the hardware. If the LEDs operate at 3 V, and the bulb's circuitry is able to maintain that voltage no matter if it's connected to AC power or not, we essentially have a low voltage uninterruptible power supply (UPS) on our hands.

PROOF OF CONCEPT The power is probably pretty "dirty", and spikes when coming on and off of AC seem likely. You should have a big capacitor across the DC side of this board at the very least. But as a quick demonstration, I was able to take the LED wires and stick them right into the 3.3 V side of a Wemos D1. Again, this isn't a great idea, but shows the basic premise is workable.

If we assume a consumption of 250 mA for the D1, this little hacked UPS should be able to run it for at least 5 hours or so. Given the advertised 3.5 hour run time figure, as well as the 2000 mAh capacity printed on the battery, this board should be able to supply at least 400 mAh at 3 V. With a boost converter you could get 5 V out of it, but probably not with enough current to run much.

A lot of people are hesitant to fiddle with AC circuitry, so the fact that this offers a turn-key solution and lets you focus on the DC side is a big plus. With the addition of an enclosure and lamp cord for the AC side, this could be an interesting "Poor Man's UPS" for microcontroller projects constructed entirely from parts available at Home Depot. There's a certain _MacGyver_ element to being able to set something like this up without having to leave your local big box store.

WORTH IT? There's some decent hardware in the bulb that might be worth the cost of admission, especially when these bulbs invariably hit the clearance section for $6 or so. The dual-brightness LED array and relatively beefy battery can be easily repurposed, for a start. It's not the best salvage deal we've seen from the Home Depot, but you could do worse.

But personally the idea of using these bulbs as a cheap DC UPS is the most appealing to me. It certainly warrants further investigation, and it would be interesting to see what the community can come up with in terms of appropriate loads to swap the LED array out for. I'll be doing some more work with this concept, so keep an eye out for a future post on the subject.

For most people, a Post-It note or dry-erase board suffices to ensure that household consumables are replenished when they're used up. But hackers aren't like most people, so this surplus barcode scanner turned kitchen inventory manager comes as little surprise. After all, if something is worth doing, it's worth overdoing.

[Brian Carrigan]'s project began with a chance discovery of an old barcode scanner in his local scrap store. Questions as to why we can never find bargains like a $500 scanner for six bucks aside, [Brian] took the scanner home for a bit of reverse engineering. He knew it used RS-232 but it had been unceremoniously ripped from its connectors, so identifying pins took some detective work. With power and data worked out and the scanner talking to a Raspberry Pi, [Brian] set about integrating it into Wunderlist,  a cloud-based list management app. Now when someone eats the last Twinkie, a quick scan of the package looks up the product name via an API call to the UPC database and posts it to Wunderlist. And we'll bet the red laser beams bouncing around the kitchen make a great nightlight too.

With smartphone barcode reading apps, this might seem a bit like overkill, but we like it just the same. And if barcodes leave you baffled, check out our introduction to these studies in black and white that adorn just about everything.

Brand new today, we're going to go all in with the Robotics Module Challenge! This is the newest part of the 2018 Hackaday Prize which is only six weeks old, and already we've seen almost six hundred incredible entries. But a new challenge means a fresh start and a perfect time for you to begin your entry.

This is your call to build a module that can be used in robotics projects across the world. Twenty module designs will be awarded $1,000 and and chance at the five top prizes including the $50,000 grand prize!

Robotics is the kitchen sink of the world of electronics. You have to deal with motors, sensors, spinny lidar doohickies, computer vision, mechatronics, and unexpected prototyping issues accounting for the coefficient of friction of 3D printed parts. Robotics is where you show your skills, and this is your chance to show the world what you've got.

Wouldn't it be great if there were some more ways to skip around the hard parts? That is the Robotics Module Challenge in a nutshell. We want to see great modular Open Hardware designs that can be used by roboticists all over the world. This might be a motor controller, a chassis or limb design system, a sensor network scheme, a communications system, data collection and delivery -- basically anything related to robotics. Build a prototype that shows how your module is used and document all the info needed to incorporate and riff on your design in other robot builds.

Start your entry now and show us your take on a great bit of Open Hardware.

The Robotics Module Challenge for the Hackaday Prize is live _right now_, and runs until 7:00 am PDT on June 4th. We're looking for modules that can be used in robotics projects around the world. Show off something that makes a robot move, sense, interact, or think, and you'll be in the running for the Grand Prize of $50,000 USD.  Start your entry now!

This article is about crypto. It's in the title, and the first sentence, yet the topic still remains hidden.

At Hackaday, we are deeply concerned with language. Part of this is the fact that we are a purely text-based publication, yes, but a better reason is right there in the masthead. This is Hackaday, and for more than a decade, we have countered to the notion that 'hackers' are only bad actors. We have railed against co-opted language for our entire existence, and our more successful stories are entirely about the use and abuse of language.

Part of this is due to the nature of the Internet. Pedantry is an acceptable substitute for wisdom, it seems, and choosing the right word isn't just a matter of semantics -- it's a compiler error. The wrong word shuts down all discussion. Use the phrase, 'fused deposition modeling' when describing a filament-based 3D printer, and some will inevitably reach for their pitchforks and torches; the correct phrase is, 'fused filament fabrication', the term preferred by the RepRap community because it is legally unencumbered by patents. That's actually a neat tidbit, but the phrase describing a technology is covered by a _trademark_, and not by a patent.

The technical side of the Internet, or at least the subpopulation concerned about backdoors, 0-days, and commitments to hodl, is now at a semantic crossroads. 'Crypto' is starting to mean 'cryptocurrency'. The netsec and technology-minded populations of the Internet are now deeply concerned over language. Cryptocurrency enthusiasts have usurped the word 'crypto', and the folks that were hacking around with DES thirty years ago aren't happy. A DH key exchange has nothing to do with virtual cats bought with Etherium, and there's no way anyone losing money to ICO scams could come up with an encryption protocol as elegant as ROT-13.

But language changes. Now, cryptographers are dealing with the same problem hackers had in the 90s, and this time there's nothing as cool as rollerblading into the Gibson to fall back on. Does 'crypto' mean 'cryptography', or does 'crypto' mean cryptocurrency? If frequency of usage determines the correct definition, a quick perusal of the press releases in my email quickly reveals a winner. It's cryptocurrency by a mile. However, cryptography has been around much, much longer than cryptocurrency. What's the right definition of 'crypto'? Does it mean cryptography, or does it mean cryptocurrency?

DOES 'CRYPTO' MEAN 'CRYPTOGRAPHY'? By far, the most convincing argument for 'crypto' meaning 'cryptography' comes from cryptoisnotcryptocurrency.com. The argument and conclusion are laid bare on a red background and the emoticon of incredulity. 'Crypto' does not mean cryptocurrency, it means cryptography. A helpful link to a Google search of 'cryptography' reinforces this argument.

Others have weighed in. [sarah jeong], senior writer for The Verge has given her opinion. 'Crypto' means 'cryptography'. [Matthew Green], who teaches cryptography at Johns Hopkins, says this is the hill he will die on.

[Lorenzo Franceschi-Bicchierai] writing for Motherboard, shares this opinion. He's written about cryptography for a few years now, and is even a fan of [Stephen Levy]'s 2001 book, _Crypto_. "'Crypto' does not mean cryptocurrency.", says Franceschi-Bicchierai, and he has the evidence to prove it. If you search Google, Merrium-Webster, or even the OED for the word 'crypto', there is only one conclusion to be made: 'crypto' means 'cryptography'.

It's not just journalists and cryptography researchers that say 'crypto' stands for 'cryptography'. [Ian Miers] is a post-doc at Cornell Tech, cryptography researcher, and very interestingly, one of the founders of Zcash, a crypto_currency_. He says, "_Crypto means cryptography. Even to whoever coined the term "cryptocurrency." That's why they used it. What, did you really think cryptocurrency starts with "crypto" because of the Loch Ness Monster?"_ A valid point, even if it does invoke cryptozoology.

*COUGH* GREEK ROOTS *COUGH*

Even if all the experts and journalists in the world agree, it doesn't make them right. 'Crypto' doesn't mean 'cryptography', because 'crypto' is a prefix, and can be applied to many words. For example, writers for Vice and Motherboard are _cryptofascists_ because they dictate the use of language to others. _Cryptosporidium_ is a parasite whose spore has a hard outer shell, allowing it to remain outside the body and resist chlorination. It can lie dormant for many months -- hidden, if you will. _Cryptomnesia, _a word with two Greek roots, is a forgotten memory remembered again.

The word 'crypto' comes from the Greek word _kruptós_, meaning 'hidden' or 'secret'. For the past three thousand years 'Crypto', or however you spell that sequence of syllables, has meant _hidden_. 'Crypto' is simply a prefix. It does not mean 'cryptography', because 'cryptography' means _hidden writing_, and 'cryptocurrency' means _secret money_ (or _secret Lambos_ for those most invested in the culture). Think of it as English's take on German's compound nouns; words can be appended to each other to derive new meanings.

So what is this article about? An argument over a prefix. No doubt the argument will continue just like our defense of the word hack. But in this case 'Crypto' really does mean hidden. 'Crypto' has meant hidden since the time of Homer, and it's not going to change just because of Bitcoin.

RTL-SDR brought cheap and ubiquitous Software Defined Radio (SDR) to the masses, opening up whole swaths of the RF spectrum which were simply unavailable to the average hacker previously. Because the RTL-SDR supported devices were designed as TV tuners, they had no capability to transmit. For the price they are still an absolutely fantastic deal, and deserve to be in any modern hacker's toolkit, but sometimes you want to reach out and touch someone.

Now you can. At OsmoDevCon [Steve Markgraf] released osmo-fl2k, a tool which allows transmit-only SDR through cheap USB 3.0 to VGA adapters based on the Fresco Logic FL2000 chip. Available through the usual overseas suppliers for as little has $5 USD, these devices can be used unmodified to transmit low-power FM, DAB, DVB-T, GSM, UMTS and GPS signals.

In a demonstration on the project page, one of these USB VGA adapters is used to broadcast a GSM cellular network which is picked up by the adjacent cell phones. Another example shows how it can be used to broadcast FM radio. A GitHub repository has been set up which includes more examples. The signals transmitted from the FL2000 chip are obviously quite weak, but the next step will logically be the hardware modifications necessary to boost transmission to more useful levels.

To say this is a big deal is something of an understatement. For a few bucks, you'll be able to get a device to spoof cellular networks and GPS signals. This was possible before, of course, but took SDR hardware that was generally outside the budget of the casual experimenter. If you bought a HackRF or an Ettus Research rig, you were probably responsible enough not to get into trouble with it, but that's not necessarily the case anymore. As exciting as this technology is, we would be wise to approach it with caution. In an increasingly automated world, GPS spoofing can have some pretty bad results.

We thought that making things levitate in mid-air by the power of sound was a little bit more like magic, or at least required fancy equipment. It turns out that you can do it yourself easily enough with parts that any decent hacker's closet should have in abundance: a motor-driver IC, two ultrasonic distance pingers, and a microcontroller. This article shows you how (translated here, scroll down).

But aside from a few clever tricks, there's not that much to show. The two HC-SR04 ultrasonic distance sensors are standard fare, and are just being used as a cheap source of 40 kHz transducers. The circuit uses a microcontroller, but any source of 40 kHz square waves should suffice. Those of you who could do that with a 555 (or a Raspberry Pi), this one's for you! A stepper motor driver bumps up the voltage applied to the transducers, but you could use plain-vanilla transistors as well.

It's all the little details that count, however. You need to position the two ultrasonic drivers fairly precisely to create a standing wave, and while you can start at 8.25 mm and trial-and-error it, the article demonstrates using an oscilloscope to align the capsules by driving one and reading the signal out of the other and tweaking them until they're in phase. Clever!

The author also takes the ultrasonic-transparent grille from one of the unused receivers and uses it as a spoon to help position the styrofoam bits in the sound waves. We always wondered how you'd do that!

It turns out that it's easy to make a DIY ultrasonic levitation desk toy, and none of the parts are expensive or critical. The missing ingredient is just the gumption to try it, and now we have that, too.

As cool as they are, the HC-SR04 modules aren't perfect for all distance sensing applications. Here's everything you need to know about them, including hacks to make them work up-close. And since HC-SR04 sensors come cheapest in ten-packs, you'll be wondering what you're going to do with the other eight. That problem has apparently also been solved.

[Fatjedi007] recently acquired three programmable boxing gym-type clocks to help his developmentally disabled clients manage their time. The plan was to have timers of varying lengths fire at preset times throughout the day, with the large displays providing a view from anywhere. Unfortunately, the clocks were not nearly as programmable as he needed them to be.

Since he'd spent enough money already, [Fatjedi007] turned to the power of Raspberry Pi to devise an affordable solution. Each clock gets a Pi Zero W and a simple IR transmit/receive circuit that operates using LIRC. The clocks came with remote controls, so it was just a matter of re-programming them. From LIRC, he wrote some scripts with SEND_ONCE and schedules the timers with a cron job. No need to get out the ladder—he can program all of them from his chair over VNC.

He does have one problem, though, and that's getting the Zeros to set themselves over NTP with static IPs. Do you have any suggestions? Put 'em in the comments and help a Jedi out.

LIRC is pretty handy for anything you want to control remotely, like a stereo system.