Day: November 22, 2018

Bar Code Adds A Third Dimension

November 22, 2018 by 40 Comments

We never really thought about it before, but a traditional barcode or QR code is pretty two dimensional. A 3D barcode sounds like marketing hype but the JAB (Just Another Barcode) system adds a third dimension in the form of color.

Traditional barcodes assume you have a pretty crude sensor, but a color camera now days is no big deal, so why not take advantage? The JAB system specifies two types of symbols: a master symbol and a slave symbol. A master symbol has four finder patterns at the corner. Slave symbols dock to a master or another docked slave.

If you want to create some JABs, there’s a web interface. If you check advanced, you can change the number of colors used, the size of each “module” (colored box), and the width and height of the master symbol. You can also arrange for error correction. The grid that shows the master and slave symbols will allow you to click on any dockable slave location to create more symbols with different attributes.

You can then save the JAB image and use the scan menu item (at the top) to read the code back. It will also read from a camera.

If you are using a color camera and a computer or phone to read barcodes, this probably is something to check out. After all, you are acquiring color data, why not use it?

You might think of the barcode as something modern, but it has a long strange history going back to the 1930s. Early barcodes looked like bullseyes and were actually inspired by Morse code. We wonder how one of these would look on someone’s arm in ink?

This Bitcoin Price Tracking Traffic Light Isn’t Just A Red LED

November 22, 2018 by 10 Comments

Quick, what’s the price of Bitcoin? Is it lower today than yesterday? Are you overdrafting your Lamborghini account? What if you had an easy way to tell at a glance how much you could have made if you sold in December of last year? That’s what this Bitcoin price tracking traffic light is all about, and it’s a great use of existing electronics.

The hardware for this build is a traffic light table lamp available on Amazon for twenty bucks. Inside this traffic light, you get a PCB with three LEDs and a small microcontroller to control the LEDs. The microcontroller isn’t used in this case, instead the microcontroller is removed and a few wires are soldered up to the base of the transistors used to drive the LEDs. The other ends of these wires are attached to a trio of pins on a Raspberry Pi Zero W, giving this traffic light table lamp Linux and a connection to the Internet.

On the software side of things, we’re looking at a Docker container running a Python script that fetches the latest Bitcoin price from Coindesk and calculates the change from the previous fetch of the price of Bitcoin. This data is shuffled off to another Python script that actually changes the LEDs on the lamp.

Sure, these days a ‘bitcoin price tracking traffic light’ is as simple as connecting a red LED to a battery, and if you’re feeling extra fancy you can add a 220 Ω resistor. But this is a project that’s so well executed that we’ve got to give it a tip ‘o our hat.

Disco Ain’t Dead: Blinky Ball Makes You Solder Inside A Dome

November 22, 2018 by 10 Comments

Disco balls take a zillion mirrors glued to a sphere and shine a spotlight on them. But what if the ball itself was the light source? Here’s a modern version that uses addressable LEDs in a 3D-printed sphere that also hides the electronics inside the ball itself.

Check out the video below to see the fantastic results. It’s a Teensy 3.6 driving a whopping 130 WS2812 LEDs to make this happen. (Even though the sphere has the lowest surface area to volume ratio.) There’s even a microphone and an accelerometer to make the orb interactive. Hidden inside is a 4400 mAh battery pack that handles recharging and feeds 5 V to the project.

For us, it’s the fabrication that really makes this even more impressive. The sphere itself is 3D printed as four rings that combine to form a sphere. This makes perfect spacing for the LEDs a snap, but you’re going to spend some time soldering the voltage, ground, and data connections from pixel to pixel. In this case that’s greatly simplified because the LEDs were sourced from AliExpress already hosted on a little circle of PCB so you’re not trying to solder on the component itself. Still, that’s something like 390 wires requiring 780 solder joints!

We love seeing an LED ball you can hold in your hand. But if you do want something bigger, try this 540 LED sphere built from triangular PCBs.

Continue reading “Disco Ain’t Dead: Blinky Ball Makes You Solder Inside A Dome” →

PLA Foils Homemade Tachometer

November 22, 2018 by 19 Comments

[Integza] built a Tesla turbine and wanted to know how fast it was spinning. However, he didn’t have a tachometer, and didn’t want to buy one. After a false start of trying to analyze the audio to measure the speed, he decided to use a tried-and-true method. Let the wheel break an infrared (IR) optointerruptor and count the spokes of the wheel as they go by. If you know the spacing between the spokes, you can compute the speed. There was only one problem: it didn’t work.

Turns out, PLA is at least somewhat transparent to IR. Knowing that it was a simple matter to fix some tape to the wheel that would block IR and that made things work much better. If you missed the video where he built the turbine, you might want to watch it first.

Continue reading “PLA Foils Homemade Tachometer” →

Tumbleweed Turbine Wins Dyson Foundation Award

November 22, 2018 by 28 Comments

Wind turbines are great when the wind flow is predictable. In urban environments, especially in cities with skyscrapers, wind patterns can be truly chaotic. What you need, then, is a wind turbine that works no matter which way the wind blows. And just such a turbine has won the global first prize James Dyson Award. Check out their video below the break.

The turbine design is really neat. It’s essentially a sphere with vents oriented so that it’s always going to rotate one way (say, clockwise) no matter where the wind hits it. The inventors say they were inspired by NASA’s Tumbleweed project, which started off as a brainstorming session and then went on to roll around Antarctica. We tumbled into this PDF, and this summary report, but would love more info if any of you out there know something about Tumbleweeds.

Back to the turbine, though. How efficient is it? How likely is it to scale? How will a 3D-printed version drive a junk-bin brushless motor on my balcony? The jury is still out. But if a significant portion of the wind comes from otherwise unusable directions, this thing could be a win. Who’s going to be the first to 3D print one?

Continue reading “Tumbleweed Turbine Wins Dyson Foundation Award” →

Kind Of The Opposite Of A Lightsaber

November 22, 2018 by 22 Comments

Lightsabers are an elegant weapon for a more civilized age. Did you ever consider that cutting people’s hands off with a laser sword means automatically cauterized wounds and that lack of blood results in a gentler rating from the Motion Picture Association? Movie guidelines aside, a cauterizing pen is found in some first aid kits, but at their core, they are a power source and a heating filament. Given the state of medical technology, this is due for an upgrade, and folks at Arizona State University are hitting all the marks with a combination of near-infrared lasers, gold particles, and protein matrix from silk.

Cauterizing relies on intense heat, or chemicals, to burn flesh but this process uses less power by aiming the near-IR laser at only the selected areas, and since near-IR can penetrate soft-tissue it goes deep without extra heating. The laser heats the gold, and that activates the silk proteins. Early results are positive but lots of testing remains and it still will not belong in the average first aid kit for a while, lasers and all, but surgery for beloved pets and tolerable humans could have recovery time reduced with this advance.

If this doesn’t sate your need for magical space knight weaponry, we have options aplenty.

Via IEEE Spectrum. Image: starwars.com

Neural Network Pies That Might Be Worth A Try

November 22, 2018 by 19 Comments

Neural networks are a key technology in the field of machine learning. A common technique is training them with sample data, and then asking them to create something new in the same vein. AI researcher [Janelle Shane] decided to task a neural network with a fun task – inventing new kinds of pie.

Using the char-rnn library, the network was initially trained on a sample of 2237 pie recipe titles, sourced from around the internet. Early iterations struggled to even spell “pie”, but as the network improved, so did the results. Where we can’t imagine how one would even make a “Sweesh Pie Ipple Pie”, later results, such as the “Impossible Maple Spinach Apple Pie” seem far more cromulent by comparison.

At this point, [Janelle] decided to mix things up, stirring in a further sample consisting of the names of various cookies and apples. The data were carefully sorted such that the network still prioritized pies, but this additional data gave the model a richer library to draw from. This led to such home-baked classics as Flangerson’s Blusty Tart and Chicken Pineapple Cream Pie.

On the surface, it’s a fun project with whimsical output, but fundamentally it highlights how much can be accomplished these days by standing on the shoulders of giants, so to speak. We’ve seen [Janelle]’s output before, too – naming tomatoes, no less.