Month: October 2019

Fast Video Covers Coax Velocity Factor

October 11, 2019 by 14 Comments

We once saw an interview test for C programmers that showed a structure with a few integer, floating point, and pointer fields. The question: How big is this structure? The correct answer was either “It depends,” or “sizeof(struct x).” The same could be said of the question “What is the speed of light?” The flip answer is 186,282 miles per second, or 299,792,458 metres per second. However, a better answer is “It depends on what it is traveling in.” [KB9VBR] discusses how different transmission lines have different velocity factors and what that means when making RF measurements. A cable with a 0.6 velocity factor sees radio signals move at 60% of that 186,282 number.

This might seem like pedantry, but the velocity factor makes a difference because it changes the actual measurements of such things as dipole legs and coax stubs. The guys make a makeshift time domain reflectometer using a signal generator and an oscilloscope.

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Tearing Down IKEA’S Sonos Speaker

October 11, 2019 by 13 Comments

There’s little better way to learn about a piece of electronics than by tearing it down. Taking a peek under the hood can reveal all manner of things about a device’s design, manufacturing, and origins. [This Does Not Compute] does a great job of doing just that, digging into the guts of IKEA’s Symfonisk speaker.

Symfonisk is a WiFi-enabled speaker, working with the Sonos ecosystem. Tearing down the device reveals some similarities to IKEA’s earlier Eneby speaker, with both devices sharing similar speaker drivers, apparently sourced from GGEC. However, upon digging deeper, it’s revealed that the Symfonisk has more in common with a speaker from another manufacturer entirely.

The video does a great job of not only investigating the manufacturing origins of the device, but breaking down the way it all works. This shows how the speaker relies on an Atheros WiFi-only chipset, thus explaining the lack of Bluetooth functionality, as well as discussing things like the neat solutions for cable management. Interestingly, the speaker uses a two-channel DAC and Class-D amplifier, but only operates in mono. Instead, the two channels are instead used to separately drive the tweeter and woofer, allowing EQ to be done in software on the main CPU, negating the need for analog crossover electronics.

It’s a teardown that would serve as a great primer for anyone considering building a piece of consumer electronics, but particularly those involved in the hi-fi space. To see how it was done way back when, perhaps try this 8-track teardown instead. Video after the break.

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Fortified Feeder For Feral Felines

October 11, 2019 by 30 Comments

Most of the commercially-available pet feeders littering the internet are cheaply-made, with wimpy motors and infuriating interfaces. Want to use it outdoors? Good luck. If you need a heavy-duty, outdoor cat feeder, you gotta heat up your soldering iron and do it yourself.

[jplanaux] is under contract to feed a bunch of feral cats that hang around, but he’s often gone for weeks at a time. His two-feeder fail-over system has one weak link, and it’s these commercial feeders — they’re under-powered and just plain unreliable, even after modding them for Raspi control. What he needed was an industrial strength automatic feeder that’s completely customized for his situation.

A simple web interface lets him set up automatic feeding times, or push kibble on demand if customers show up and there’s no food. The system takes pictures of the bowl to verify that food came out and was subsequently eaten. It’s supposed to be racoon-proof, so [jplanaux] can see who or what is chowing down. Aside from that, the feeder is pretty standard, with a large hopper on top of a screw drive that’s driven by a NEMA17. The stepper is relay-driven, so it only uses power when it’s driving the screw.

[jplanaux] has the STL files and code available, and even designed a bowl and base extension for people who want to build one and use it indoors. Nibble at the kibble-sized demo video after the break.

The lion’s share of the auto-feeder builds we chew on around here are designed for dry food. Serving wet food is a much harder problem, but is definitely possible to pull off.

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Portrait Painter Turns G-Code Into Artworks

October 11, 2019 by 5 Comments

Portrait painting is, by and large, a human endeavour. But, like any and all skills, there are machines ready and willing to take a crack at it. [Jose Salatino] has built just such a machine, and the results are impressive.

Samples of the artwork created by [Jose’s] portrait painter.
[Jose’s] portrait painter relies on a Cartesian CNC setup, with an X-Y gantry fitted with a retractable brush carrier. The carrier holds four brushes, allowing the device to paint with different sized strokes as per the artistic requirements. An algorithm is used to turn images into a series of brushstrokes, which are then turned into G-code to drive the system. Colors are mixed just like a human painter would, with the brush dipping into a series of paint pots. Using the hue-saturation-brightness (HSB) color system makes this easy.

While it’s much slower than your average printer, the goal here isn’t to create photorealistic images, but to create something with artistic appeal. The artworks painted by the ‘bot have a remarkable likeness to oil paintings by human artists, thanks to using similar techniques. We’re sure [Jose’s] experience as an oil painter helped out here, too.

We’ve seen other ‘bots produce custom artworks before, too. Video after the break.

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Latest Dose Of Hardware Talks Headed To Supercon

October 11, 2019 by No comments

The tickets have sold out even as the list of incredible speakers grows. Today we bring you the third dose of talks you’ll see at the Hackaday Superconference in November — whether you were lucky enough to grab a ticket, or will be watching the livestream, these eight will be speaking on topics from algorithmically-augmented live music performance to the hardware that captures the real world for display in VR and from leveraging the power of lookup tables to harnessing our engineering talent in a way that truly enriches humanity.

If you missed the two speaker announcements that have already come out, go back and take a look at those as well as the workshops being held during Supercon.

The Talks (Part Three of Many)


  • Mitch Altman

    The Pros and Cons of Tech. Can We Design Tech that Serves Humanity

    Technology is truly awesome! It is also a lot of fun. With the tools we, as humans, have made through the eons, we’ve become top-dog on our planet. But, at a great cost. It is mostly accepted that we have only 5 years to reverse climate change. How long till we no longer have any privacy. We have little time for anything but work because of all of our addictive and alienating “time-saving” devices we voluntarily choose to have in our lives. People report being less happy each decade. Soon, only 2% of the world’s wealth will be concentrated in only 0.1% of the population. The military uses anything and everything we create to spy, destroy, and kill for profit. This is not a pretty picture. What can we do? Is it possible to create technology to improve our lives? In this inspirational talk I will use personal experience to explore aspects of this important discussion.


  • Sara Adkins

    Creating with the Machine: Algorithmic Composition for Live Performances

    In a live concert setting, the movement and energy of performers add an important emotional element to the audience’s listening experience. Computer-generated music can achieve unique sounds and precise technique not possible by human musicians, yet it can feel alienating and impersonal due to a lack of human connection and spontaneity. “Creating with the Machine” is a set of compositions that combine algorithmic and traditional methods of music composition into live performances to explore how interactive generative algorithms can influence creativity in musical improvisation, and create a compelling listening experience for the audience. In this talk, I will introduce techniques for creating a meaningful data representation of a musician’s performance, and methods for using this input data to control a closed loop algorithmic composition.


  • Kate Morris

    Beyond Blinky – Developing Retro-Games for PCB Badgess

    So, you’ve done some badge coding, maybe using Arduino, and are looking for the next step to write interactive games using a TFT screen and some buttons and sensors? Using the open-source for the Lunar Lander badge (built for DEF CON 27) I will explain how we created the framework and how you can adapt it to write your own games for this badge or for your own conference badge. We’ll step through the process for developing a new game, and discuss some of the challenges we had in creating the Lunar Lander game.


  • Dave Young

    Scrounging, Sipping, and Seeing Power

    Powering low power and ultra-low power systems is more about system design than circuit design. Selecting the right power source, using the power effectively, and then validating that the power numbers are as expected is critical at an early stage since changes may trigger a system redesign (or product failure). I will review some of the typical design decisions to make, some general back-of-the-envelope figures, and some techniques on how to plan the power use and validate a prototype. We’ll discuss questions like: How can I decide if I should be on a primary battery, solar, or kinetic energy system? How can I estimate the total usable energy from a solar panel given real-world conditions? Do I need MPPT? And how can I estimate my total energy consumption?


  • Ruth Grace Wong

    How to become a manufacturing engineer in your spare time

    It’s one thing to prototype something for yourself, and entirely another to productionize a product for manufacturing. This talk is about my quest to become a manufacturing engineer. In the summer of 2016, I decided that I would do software at scale at my full time job, and hardware and objects at scale in my spare time. Since then, I’ve worked on many personal projects to get the intuitive physical feel for how things are made while documenting what I’ve learned, started writing about manufacturing for Supplyframe Hardware allowing me to tour factories and interview manufacturers, and started working part-time as a manufacturing engineer.


  • Kim Pimmel

    Beyond the Rectangle: Building Cameras for the Immersive Future

    Ever since the earliest days of photography, we’ve tried to capture and play back the world around us. Today, immersive technologies like AR and VR are pushing beyond the 2D image, seeking to replicate more and more of the human experience. This is driving growth in new imaging, sensory, and display technologies.

  • Learn about some cameras I’ve made, trends in camera technology, and how building the Matrix is hard.

  • Scott Shawcroft

    Supercharge Your Hardware (Old and New) with CircuitPython

    CircuitPython makes programming hardware easier than ever by bringing the popular Python language to modern, inexpensive 32-bit microcontrollers. This doesn’t need to be limited to modern hardware though. By pairing a modern microcontroller running CircuitPython and a vintage computer, such as a GameBoy or Yamaha piano keyboard, you can unlock the unique characteristics of these vintage devices. In this talk, you’ll learn the basics of how CircuitPython makes coding easy, how it works under the hood, and how to extend CircuitPython with C. As an example, we’ll supercharge a Nintendo’s GameBoy with CircuitPython. By the end of the talk, you’ll be able to supercharge your own hardware project with CircuitPython.


  • Charles Lohr

    Accomplishing the Impossible with LUTs.

  • I’ve done some very bizarre and extreme things with microcontrollers over the last several years. From bit-banging (Tx and Rx) Ethernet on an ATtiny85 broadcasting video from an ESP8266 GPIO pin to writing USB stacks for chips that don’t have them, the most insane and counter-intuitive projects that have been successes have all had one thing in common. At the heart of the project is one or more lookup tables (LUTs). In computer science classes, we study algorithms like Dynamic Programming and we hear about LUTs, but we rarely discuss the true power of this game-changing tool. In this talk I will explore how to reform complicated problems in such a way to do processing faster and on smaller processors than you ever thought possible.

 

See You at Supercon!

We’re so excited to see everyone at Supercon this year. As mentioned above, tickets are sold out so if something comes up and you can’t make it, please request a ticket refund so we can make your spot available to people on the waitlist.

Hackaday Podcast 039: Elliot <3 Lightning Detectors, Ikea Dark Mode, The Smartest Watch, Solar Sailing The Sky, And VAWT Controversy

October 11, 2019 by 1 Comment

Hackaday Editors Elliot Williams and Mike Szczys recap a week full of hacks from the solar sailing RC plane that has zero power storage, to geeking out about lightning detectors and hacking Ikea LED controllers to unlock real dimming to building backyard wind turbines. We look up an IoT egg tray with appreciation not for the concept but certainly for the engineering, and scratch our heads on why one-hacker-smartwatch-to-rule-them-all seems like something that should happen but so far has only been a fleeting concept.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Everything Makes Sound If You Try Hard Enough

October 11, 2019 by 8 Comments

Speaker cone materials can be a deep rabbit hole ranging from inexpensive paper to kevlar. We’ve all cut apart, or blown out, the cheapies to see their inner workings, but the exotic material list does not stop at audiophile-quality models. It can include mirrors, microwave ovens, and a European hacker’s forehead. Video also after the break. In addition to the speakers with expensive elements, there are sound-generating transducers with no cones. These are sometimes called surface speakers, and they vibrate something, anything, to make a sound. At their cores, they have many of the same parts, and making a surface speaker from a traditional speaker is not difficult.

The first step is to find a raw speaker, one with no crossover components, possibly from a garage sale or from a set your spouse insists are outdated, ugly, and better off as firewood. Power specifications should not change since we will be using the same solenoid, and that means your amplifier can follow the speakers back from the dead. The video provides step-by-step instructions, and the goal is to create a module with a moving shaft, but the range must be limited so it cannot be pushed back into the speaker or pulled away, both could destroy it. Once you have that, go around and make everything noisy. Don’t use this on pets or children, but spouses are fair game.

We would love to see a chip bender experiment with different speaker mediums to add an extra layer of complexity, but for the rest of us, bone conduction is already a real thing, and if you enjoy impractical speakers, you are not the only one with your head in the clouds.

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