A machine that holds a combination padlock and turns its dial, with two padlocks next to it

Robot Opens Master Combination Locks In Less Than A Minute

A common trope in bank heist B-movies is someone effortlessly bypassing a safe’s combination lock. Typically, the hero or villain will turn the dial while listening to the internal machinery, then deduce the combination based on sounds made by the lock. In real life, high-quality combination locks are not vulnerable to such simple attacks, but cheap ones can often be bypassed with a minimum of effort. Some are so simple that this process can even be automated, as [Mew463] has shown by building a machine that can open a Master combination lock in less than a minute.

A machine that holds a combination padlock and turns its dialThe operating principle is based on research by Samy Kamkar from a couple of years ago. For certain types of Master locks, the combination can be found by applying a small amount of pressure on the shackle and searching for locations on the dial where its movement becomes heavier. A simple algorithm can then be used to completely determine the first and third numbers, and find a list of just eight candidates for the second number.

[Mew463]’s machine automates this process by turning the dial with a stepper motor and pulling on the shackle using a servo and a rack-and-pinion system. A magnetic encoder is mounted on the stepper motor to determine when the motor stalls, while the servo has its internal position encoder brought out as a means of detecting how far the shackle has moved. All of this is controlled by an Arduino Nano mounted on a custom PCB together with a TMC2208 stepper driver.

The machine does its job smoothly and quickly, as you can see in the (silent) video embedded below. All design files are available on the project’s GitHub page, so if you’ve got a drawer full of these locks without combinations, here’s your chance to make them sort-of-useful again. After all, these locks’ vulnerabilities have a long history, and we’ve even seen automated crackers before.

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Hacking A Jack-in-the-Box To Be Extra Surprising

A Jack-In-The-Box is scary enough the first time. However, if you’ve seen the clown pop out before, it fails to have the same impact. [Franklinstein] decided that swapping out the clown for an alternative payload would deliver the fright he was after.

Inside the toy, an Arduino Nano runs the show. It’s paired with an airhorn, installed in a special frame along with an RC servo. When the time is right, the RC servo presses up against the airhorn, firing off an almighty noise. There’s also a confetti blaster, built with a small chamber full of compressed air. When a solenoid is released, the compressed air rushes out through a funnel full of confetti, spraying it into the room.

When the crank on the toy is turned, the typical song plays. When the lid of the box opens, it releases a switch, and the Arduino fires off the confetti and airhorn. It’s shocking enough for [Franklinstein] himself, and even more surprising for those expecting the toy’s typical bouncing clown instead.

We’d love to see an even more obnoxious version that doesn’t turn the airhorn off for at least a full minute. We’ve seen them employed in some great Halloween hacks before, too. Video after the break.

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Fireball-Flinging Figurine Feeds Fiction

If you’re writing a screenplay or novel, there will likely be points along the way at which you can’t get enough encouragement from friends and family. While kind words are kind, acts such as [scubabear]’s can provide a push like no other. By commissioning another 3D designer friend to model a character from the first friend’s screenplay so he could print and animate it, [scubabear] fed two birds with one scone, you might say.

Designer friend [Sean] modeled the mighty Braomar in Maya and Z-brush, and [scubabear] did test prints on a Formlabs Form2 as they went along to keep an eye on things. Eventually, they had a discussion about making space for wires and such, so [Sean] took to Blender to make Braomar hollow enough for wires, but not so empty that he would collapse under the stress of being (we presume) the main character.

Braomar stands upon a sigil that changes color thanks to an RGB LED ring in the base that’s driven by an Arduino Nano. A single pixel in the fireball is wired through Braomar’s body and flickers with the help of an addressable LED sequencer board.

Our favorite part of this build has to be the power scheme. Not content to have a wire running out from the base or even a remote control for power-draining concerns, [scubabear] used disc magnets in the base to switch on the 9 V battery when Screenplay Friend rotates it.

Of course, if you need inspiration to even thing about beginning to write a screenplay or novel, maybe you should lead with the maquette-building and then construct a story around your creation.


This project was an entry into the 2022 Sci-Fi Contest. Check out all of the winning entries here.

A USB interface connected to a Psion Organiser II

Arduino Nano Adds USB Interface To The Psion Organiser II

Introduced in 1984, the Psion Organiser series defined the first generation of electronic organizers or PDAs (personal digital assistants). Even though these devices are now over 30 years old, the Psion Organiser scene is alive and well: with new hardware and software is still being developed by enthusiasts the world over.

A USB interface connected to a Psion Organiser II
The Organiser II, with its brand-new USB interface

One of those enthusiasts is [James Stanley], who designed and built a USB interface for the Psion Organiser II. Although a “CommsLink” module providing an RS-232 port was available back in the day, it’s become hard to find, inspiring [James] to design a completely new module based on an Arduino Nano. Hooking it up to the Psion’s data bus was a simple matter of wiring up the eight data lines to the Nano’s GPIO ports. A set of series resistors served to prevent bus contention without having to add glue logic.

Getting the software working was a bit more difficult: the Organiser’s native OPL programming language doesn’t allow the user to directly access the expansion port’s memory address, so [James] had to write a routine in HD6303 machine code to perform the read, then call that routine from OPL to display the result on the screen. Currently, the routine only supports reading data from the Arduino, but extending it to a bidirectional interface should be possible too.

Finally, [James] designed and 3D printed a neat enclosure for the Arduino-USB interface, which makes it look almost as sleek as the original CommsLink module. Perhaps with a bit of further development, this could turn into another way to connect old Psions to the internet. We’ve also featured a new type of Datapak to enhance the Organiser’s memory. Continue reading “Arduino Nano Adds USB Interface To The Psion Organiser II”

Miniature Space Invaders game

Arduino And An OLED Make This Space Invaders Cabinet Tiny

For as simple as it appears now, Space Invaders was one machine from the Golden Age of video games that always seemed to have a long line waiting for a chance to lose a couple of quarters. And by way of celebrating the seminal game’s influence, [Nick Cranch] has executed what might just be the world’s smallest Space Invaders replica.

It appears that this started mainly as an exercise in what’s possible with what’s on hand, which included a couple of quite small OLED displays. For the build photos it looks like there’s an Arduino Nano running the show; [Nick] relates that the chosen hardware proved challenging, and that he had to hack the driver library to make it work. Once he got a working game, [Nick] didn’t rest on his laurels. Rather, he went the extra mile and built a miniature cabinet to house everything in.

The video quality below may be poor, but it’s more than enough to see how much work he put into detailing the cabinet. The graphics of the original US release of the game cabinet are accurately represented, right down to the art on the front glass. The cabinet itself is made from 1.5 mm plywood which he cut by hand. It even looks like he recreated the original scheme of cellophane overlays on the monochrome screen to add a little color to the game. Nice touch!

We really appreciate the attention to detail here, with our only quibble being no schematics or code being posted. Hopefully, we’ll see those later, but for now, this looks like a fun project and a nice trip down memory lane. But if you think it’s too small, no worries — we’ve got a much, much bigger version of the game too.

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Turing Ring Is Compact

One of the problems with a classic Turing machine is the tape must be infinitely long. [Mark’s] Turing Ring still doesn’t have an infinite tape, but it does make it circular to save space. That along with a very clever and capable UI makes this one of the most usable Turing machines we’ve seen. You can see a demo in the video below.

The device uses an Arduino Nano, a Neopixel ring, an encoder, and a laser-cut enclosure that looks great. The minimal UI has several modes and the video below takes you through all of them.

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A portable Bluetooth turntable.

Bluetooth Record Player Puts A New Spin On Vinyl

You know, we were just discussing weird and/or obsolete audio formats in the writers’ dungeon the other day. (By the way, have you ever bought anything on DAT or MiniDisc?) While vinyl is hardly weird or (nowadays) obsolete, the fact that this Bluetooth record player by [JGJMatt] is so modern makes it all the more fantastic.

Not since the Audio-Technica Sound Burger, or Crosley’s semi-recent imitation, have we seen such a portable unit. But that’s not even the most notable part — this thing runs inversely to normal record players. Translation: the record stands still while the the player spins, and it sends the audio over Bluetooth to headphones or a speaker.

Inside this portable player is an Arduino Nano driving a 5 VDC motor with a worm gear box. There really isn’t too much more to this build — mostly power, a needle cartridge, and a Bluetooth audio transmitter. There’s a TTP223 touch module on the lid that allows [JGJMatt] to turn it off with the wave of a hand.

[JGJMatt] says this is a prototype/work-in-progress, and welcomes input from the community. Right now the drive system is good and the Bluetooth is stable and able, but the tone arm has some room for improvement — in tests, it only played a small section of the record and skidded and skittered across the innermost and outermost parts. Now, [JGJMatt] is trying two-part arm approach where the first bit extends and locks into position, and then a second arm extending from there and moves around freely.

Commercial record players can do more than just play records. If you’ve got an old one that isn’t even good enough for a thrift store copy of a Starship record, you could turn it into a pottery wheel or a guitar tremolo.