Smartphone Controlled Periodic Table of Elements

It wouldn’t be much of a stretch to say that here at Hackaday, we’re about as geeky as they come. Having said that, even we were surprised to hear that there are people out there who collect elements. Far be it from us to knock how anyone else wishes to fill their days, but telling somebody at a party that you collect chemical elements is like one step up from saying you’ve got a mold and fungus collection at home. Even then, at least a completed mold and fungus collection won’t be radioactive.

But if you’re going to spend your spare time working on a nerdy and potentially deadly collection, you might as well put it into an appropriate display case. You can’t just leave your Polonium sitting around on the kitchen counter. That’s the idea behind the interactive periodic table built by [Maclsk], and we’ve got to admit, if we get to put it in a case this awesome we might have to start our own collection.

A large portion of this project is building the wooden display case itself as, strangely enough, IKEA doesn’t currently stock a shelving unit that’s in the shape of the periodic table. The individual cells and edge molding are made of pine, the back panel is MDF, and the front of the display is faced off with thin strips of balsa to cover up all the joints. Holes were then drilled into the back of each cell for the LED wiring, and finally the entire frame was painted white.

Each cell contains an WS2812B RGB LED, which at maximum brightness draws 60mA. Given the 90 cells of the display case, [Maclsk] calculated a 5.4A power supply would be needed to keep everything lit up. However, he found a 4A power supply that made his budget happier, which he reasons will be fine as long as he doesn’t try to crank every cell up to maximum at the same time. Control for the display is provided by an Arduino Nano and HC05 Bluetooth module.

The final piece of the project was the Android application that allows the user to control the lighting. But it doesn’t just change colors and brightness, it’s actually a way to visualize information about the elements themselves. The user can do things like highlight certain groups of elements (say, only the radioactive ones), or light up individual cells in order of the year each element was discovered. Some of the information visualizations are demonstrated in the video below, and honestly, we’ve seen museum displays that weren’t this well done.

We last caught up with [Maclsk] when he created a very slick robotic wire cutting machine, which we can only assume was put to work for this particular project. Too bad he didn’t have a robot to handle the nearly 540 soldering joints it took to wire up all these LEDs.

[via /r/DIY]

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Spoof a Skimmer for Peace of Mind

It’s a sad commentary on the state of the world when it becomes a good practice to closely inspect the card reader on every ATM and gas pump for the presence of a skimmer. The trouble is, even physically yanking on the reader may not be enough, as more sophisticated skimmers now reside safely inside the device, sipping on the serial comms output of the reader and caching it for later pickup via Bluetooth. Devilishly clever stuff.

Luckily, there’s an app to detect these devices, and the prudent consumer might take solace when a quick scan of the area reveals no skimmers in operation. But is that enough? After all, how do you know the smartphone app is working? This skimmer scammer scanner — or is that a skimmer scanner scammer? — should help you prove you’re being as safe as possible.

The basic problem that [Ben Kolin] is trying to solve here is: how do you prove a negative? In other words, one could easily write an app with a hard-coded “This Area Certified Zebra-Free” message and market it as a “Zebra Detector,” and 99.999% of the time, it’ll give you the right results. [Ben]’s build provides the zebra, as it were, by posing as an active skimmer to convince the scanner app that a malicious Bluetooth site is nearby. It’s a quick and dirty build with a Nano and a Bluetooth module and a half-dozen lines of code. But it does the trick.

Need a primer on the nefarious world of skimming? Here’s an overview of how easy skimming has become, and a teardown of a skimmer captured in the wild.

Robot: Do My Bidding!

Remote control robots are nothing new. Using Bluetooth isn’t all that unusual, either. What [SayantanM4] did was make a Bluetooth robot that accepts voice commands via his phone. The robot itself isn’t very remarkable. An Arduino and an HC05 module make up most of the electronics. A standard motor driver runs the two wheels.

The Arduino doesn’t usually do much voice processing, and the trick is–of course–in the phone application. BT Voice Control for Arduino is a free download that simply sends strings to a host computer via Bluetooth. If you say “Hello” into your phone, the robot receives *Hello# and that string could be processed by any computer that can receive Bluetooth data.

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Convert Any USB Keyboard to Bluetooth

[DastardlyLabs] saw a video about converting a PS/2 keyboard to Bluetooth and realized he didn’t have any PS/2 keyboards anymore. So he pulled the same trick with a USB keyboard. Along the way, he made three videos explaining how it all works.

The project uses a stock DuinoFun USB mini host shield with a modification to allow it to work on 5V. An Arduino mini pro provides the brains. A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware installed. [Dastardly] makes a homemade daughterboard–er, shield–to connect it to the Arduino.

The result is a nice little sandwich with a USB plug, a Bluetooth antenna, and some pins for reprogramming if necessary. Resist the urge to solder the Bluetooth board in–since it talks on the same port as the Arduino uses for programming, you’ll have to remove it before uploading new code.

If you need help reprogramming the HC-05 Bluetooth module, we’ve covered that before. This project drew inspiration from [Evan’s] similar project for PS/2 keyboards.

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