Threat Meter Gauges Risk of Creeper-Assisted Suicide

If you’ve played even just a few minutes of Minecraft, you know what a creeper is. For those not familiar with the wildly popular sandbox game, a creeper is a monster that creeps along silently until it’s close to a player, whereupon it self-destructs by exploding. Sometimes it kills the player outright, and other times the explosion blows them into lava or off a cliff, or off a cliff and then into lava. Creepers have no friends.

But now there’s a way to avoid creeper attacks, or at least get a little heads up that these green nasties are lurking about. With [John Allwine]’s creeper detector, Minecraft players can get a real-world indicator of the current in-game creeper threat. The hardware end is simple enough — it’s just a SparkFun RedBoard and a small strip of Neopixels in a laser-cut plywood case. The LEDs lie behind a piece of etched acrylic to diffuse their glow — extra points for the creeper pattern in the lens. The detector talks over USB to a Minecraft mod that [John] wrote to interface the game with the real world. The closer a creeper gets to the player, the brighter the light. — and when it flashes, watch out. See it in action in the video below, if you can stomach watching someone dig straight down. Never dig straight down.

If interfacing the Minecraft world and the real world sounds familiar, maybe it’s because we featured [John]’s SerialCraft mod a while back and admired the potential for using Minecraft as a gateway for getting kids into hardware hacking. We agree that this is a great project to work on with kids, but we may just order the parts to do it for our own Minecraft world. Creeper hate isn’t just for kids.

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Careful Testing Reveals USB Cable Duds

What’s worse than powering up your latest build for the first time only to have absolutely nothing happen? OK, maybe it’s not as bad as releasing the Magic Smoke, but it’s still pretty bewildering to have none of your blinky lights blink like they’re supposed to.

What you do at that point is largely a matter of your troubleshooting style, and when [Scott M. Baker]’s Raspberry Pi jukebox build failed to chooch, he returned to first principles and checked the power cable. That turned out to be the culprit, but instead of giving up there, he did a thorough series of load tests on multiple USB cables to see which ones were suspect, with interesting results.

[Scott] originally used a cable with a USB-A on one end and a 3.5-mm barrel plug on the other with a switch in between, under the assumption that the plug on the Pi end would be more robust, as well as to have a power switch for the jukebox. Testing that cable using an adjustable DC load would prove that the cable was unfit for Pi duty, dropping the voltage to under 2 volts at a measly 500-mA load. Other cables proved much better under load, even those with USB mini jacks and even one with a 5.5-mm barrel. But the larger barrel-plug cable also proved to be a stinker when it was paired with an inline switch. In the video below, [Scott] walks through not only the testing process, but also gives a quick tour of his homebrew DC load.

The lesson is clear: not all USB cables are created equal, so caveat hacker. And if you’ve got a yen to check the cables in your junk bin like [Scott] did, this full-featured smart DC load might be just the thing.

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Tomu: A Microcontroller for Your USB Port

Looking for a ultra tiny development board? Tomu is an ARM Cortex M0+ device that fits inside your USB port. We’ve seen these in person, and they’re tiny.

There’s a few commercial devices in this form factor on the market. For example, the Yubikey Nano emulates a keyboard to provide codes for two-factor authentication. The Yubikey’s tiny hardware does this job well, but the closed-source device isn’t something you can modify.

Tomu is a new device for your USB port. It sports a Silicon Labs EFM32 microcontroller, two buttons, and two LEDs. This particular microcontroller is well suited to the task. It can talk USB without a crystal for timing, and has an internal regulator to generate the core voltage from a 5 V USB supply. Since it supports DFU firmware updates, it can be reprogrammed without any special tools.

Unfortunately, the EFM32 device lacks secure storage options, so the Tomu might not be the best device to keep your secrets on. That being said, it will be interesting to see what applications people come up with. The creators have suggested using the device for media buttons, sleeping and waking a computer, and as a U2F key.

The project is currently available on CrowdSupply, and all design files and source is available on their Github. If you like soldering tiny things, the twelve-part bill of materials should be fairly easy to assemble at home.

This USB Drive Will Self-Destruct After Ruining Your Computer

Who would have thought that you could light up pyrotechnics on USB power? This USB keystroke injector that blows up after it’s used proves the concept.

Fully aware that this is one of those “just because you can doesn’t mean you should” projects, [MG] takes pains to point out that his danger dongle is just for dramatic effect, like a prop for a movie or the stage. In fact, he purposely withholds details on the pyrotechnics and concentrates on the keystroke injection aspect, potentially nasty enough by itself, as well as the dongle’s universal payload launching features. We’re a little bummed, because the confetti explosion (spoiler!) was pretty neat.

The device is just an ATtiny85 and a few passives stuffed into an old USB drive shell, along with a MOSFET to trigger the payload. If you eschew the explosives, the payload could be anything that will fit in the case. [MG] suggests that if you want to prank someone, an obnoxious siren might be a better way to teach your mark a lesson about plugging in strange USB drives.

While this isn’t the most dangerous thing you can do with a USB port, it could be right up there with that rash of USB killer dongles from a year or so ago. All of these devices are fun “what ifs”, but using them on anything but your own computers is not cool and possibly dangerous. Watching the smoke pour out of a USB socket definitely drives home the point that you shouldn’t plug in that thumbdrive that you found in the bathroom at work, though.

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Home Decorating with Tiny Arcade Cabinets

Thanks to the general miniaturization of electronics, the wide availability of cheap color LCD screens, and the fact that licensing decades old arcade games is something of a free-for-all, we can now purchase miniature clones of classic arcade cabinets for about $20 USD. In theory you could play these things, but given they’re less than 4 inches in height they end up being more of a desk novelty than anything. Especially since it seems like most of the effort went into making the cabinet itself; a classic example of “form over function”.

Unfortunately, if you want to buy these little arcade cabinets to use as decoration for your office or game room, they aren’t particularly well suited to the task. The “demo” mode where the game plays itself doesn’t last for very long, and even if it did, the game would chew through batteries at an alarming rate. [Travis] decided to tackle both issues head on by powering his Tiny Arcades over USB and locking them into demo mode.

The stock power for the Tiny Arcade comes from three AAA batteries, or 4.5 V. This made it easy enough to run over  5 V USB, and a four port USB charger is used to provide power to multiple machines at once. Forcing the game to stay in demo mode wasn’t much harder: a 555 timer was used to “push” the demo button with a frequency of every 10 seconds or so to keep the game up and running. A simple timer circuit was put together in the classic “dead bug” style, and sealed up with liquid rubber so it would play nice with the insides of the Tiny Arcade.

Since his little machines wouldn’t need their stock power switches anymore, [Travis] rewired the speaker lead through it. So now the machine stays on and in demo mode as long as it’s plugged into USB power, and you can flip the switch on the back to turn off the sounds. Perfect for sitting up on a shelf or the corner of your desk.

Usability issues not withstanding, there’s a pretty big (no pun intended) following for micro sized arcade cabinets. We’ve seen projects ranging from modding a Game Boy Advance to even tinier scratch builds.

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Logic Analyzer Pushes the Limits of Miniaturization

Careful not to sneeze while using this diminutive logic analyzer — you could send it flying across the bench.

Undertaken more for the challenge than as a practical bench tool, [Uwe Hermann]’s tiny logic analyzer is an object lesson on getting a usable circuit as small as possible. Sure, some sacrifices had to be made; it’s only an eight-channel instrument without any kind of input protection at all, and lacks niceties like an EEPROM. But that allows it to fit on a mere 11 x 11-mm fleck of PCB. That’s a pretty impressive feat of miniaturization, given that the Cypress microcontroller running the show is in QFN package that takes up 64-mm² all by itself. A micro-USB connector takes up much of the back side of the board and allows the analyzer to talk to sigrok, an open-source signal analysis suite.

Everything about the project is totally open, including the PCB files, so you can build your own if you feel up to the challenge. We’d strongly suggest you check out this primer on logic analyzers first, though, especially since it focuses on the capabilities of the sigrok suite.

Brute Forcing Passwords with a 3D Printer

Many of us use a 4 digit pin code to lock our phones. [David Randolph] over at Hak5 has come up a simple way to use a 3D printer to brute force these passwords. Just about every 3D printer out there speaks the same language, G-code. The same language used in CAD and CNC machines for decades.

[David] placed a numeric keypad on the bed of his printer. He then mapped out the height and positions of each key. Once he knew the absolute positions of the keys, it was easy to tell the printer to move to a key, then press and release. He even created a G-code file which would press every one of the 10,000 4 key pin combinations.

A file this large was a bit unwieldy though, so [David] also created a python script which will do the same thing — outputting the G-code and coordinates to brute force any 4 pin keypad. While a printer is quite a bit slower than Hak5’s own USB Rubber Ducky device (which acts as an automated keyboard), it will successfully brute force a password. Although most phones these days do limit the number of password attempts a user gets.

[David] admits this is probably useless in a clandestine/hacking application, but the video is still a great introduction to G-code and using 3D printers for non-printing functions.

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