Riddle: What Metal Conducts Electricity, But Not Heat?

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If you can’t answer the riddle, don’t feel bad. Metal conductors usually conduct electricity and heat. Usually, that’s true, but researchers at the Department of Energy’s Lawrence Berkeley National Laboratory and at the University of California, Berkeley, have found that vanadium dioxide can conduct electricity without conducting heat.

The Wiedemann-Franz Law states that good conductors of electricity are also good conductors of heat. Vanadium dioxide not only switches from an insulator to a conductor at 67C (152F), but it appears that it also doesn’t conduct as much heat as that law predicts while it is in its electrically conductive phase. …read more

Let’s Prototype! This Filament End Needs 80 Decibels

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Reaching the end of a spool of filament when 3D printing is inevitable. The result ranges from minor annoyance to ruined print. Recently, I needed to print a number of large jobs that used just over half a spool of plastic each. Unwilling to start every print with a fresh spool (and shelve a 60% used one afterward), I had a problem to solve. What my 3D printer needed was filament monitor, or at least that’s what I thought.

After reviewing some projects and aftermarket options, I ended up making my own. Like most prototypes, it wasn’t an instant success,

…read more

Build Your Own P-Brain

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I don’t think we’ll call virtual assistants done until we can say, “Make me a sandwich” (without adding “sudo”) and have a sandwich made and delivered to us while sitting in front of our televisions. However, they are not completely without use as they are currently – they can let you know the time, weather and traffic, schedule or remind you of meetings and they can also be used to order things from Amazon. [Pat AI] was interested in building an open source, extensible, virtual assistant, so he built P-Brain.

Think of P-Brain as the base for a more complex …read more

A Heart for His Girlfriend

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[Decino] made a nice LED animated blinking heart box for his girlfriend. That’s a nice gesture, but more to the point here, it’s a nice entrée into the world of custom hardware. The project isn’t anything more than a home-etched PCB, a custom 3D-printed case, a mess of LEDs and current-limiting resistors, a shift register, and a microcontroller. (OK, we’re admittedly forgetting the Fifth Element.) The board is even single-sided with pretty wide traces. In short, it’s a great first project that ties together all of the basics without any parts left over. Oh, and did we mention Valentine’s day? …read more

3D Printing Makes Electronics A Snap

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For just about as long as there have been electronics, there’s been a search for a way to let students and hobbyists build projects without a lot of effort. A board with Fahnestock clips was probably the first attempt. Today, it is more often the ubiquitous solderless breadboard. In between, we’ve seen copper pipe pieces and rubber bands, components mounted on magnets that hold them and make connections, and other even less probable schemes. A few years back, a new method appeared: Snap Circuits. The name almost says it all. A baseboard has mounting holes for different components. All the …read more

Add Broken Tool Detection to Your CNC Mill

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A tool breaking in the midst of a CNC machining operation is always a disaster. Not only do you have a broken tool (no small expense), but if the program continues to run there is a good chance it’ll end up ruining your part too. In particularly bad cases, it’s even possible to for this to damage the machine itself. However, if the breakage is detected soon enough, the program can be stopped in time to salvage the part and avoid damage to your machine.

Many new machining centers have the ability to automatically detect tool breaks, but this is …read more

PCB Design Guidelines to Minimize RF Transmissions

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There are certain design guidelines for PCBs that don’t make a lot of sense, and practices that seem excessive and unnecessary. Often these are motivated by the black magic that is RF transmission. This is either an unfortunate and unintended consequence of electronic circuits, or a magical and useful feature of them, and a lot of design time goes into reducing or removing these effects or tuning them.

You’re wondering how important this is for your projects and whether you should worry about unintentional radiated emissions. On the Baddeley scale of importance:

  • Pffffft – You’re building a one-off project that

…read more

PCB Design Guidelines to Minimize RF Transmissions

See the original posting on Hackaday

There are certain design guidelines for PCBs that don’t make a lot of sense, and practices that seem excessive and unnecessary. Often these are motivated by the black magic that is RF transmission. This is either an unfortunate and unintended consequence of electronic circuits, or a magical and useful feature of them, and a lot of design time goes into reducing or removing these effects or tuning them.

You’re wondering how important this is for your projects and whether you should worry about unintentional radiated emissions. On the Baddeley scale of importance:

  • Pffffft – You’re building a one-off project that

…read more

The Zimmermann Telegram

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World War I began in 1914 as a fight among several European nations, while the United States pursued a policy of non-intervention. In fact, Woodrow Wilson was reelected President largely because “He kept us out of war”. But as the war unfolded in Europe, an intercepted telegram sent by the German Foreign Secretary, Arthur Zimmermann, to the Mexican government inflamed the U.S. public opinion and was one of the main reasons for the entry of the U.S. into WWI. This is the story of the encrypted telegram that changed the last century.

ORIGIN OF THE GERMAN OFFER

Germany was actively …read more

The Zimmermann Telegram

See the original posting on Hackaday

World War I began in 1914 as a fight among several European nations, while the United States pursued a policy of non-intervention. In fact, Woodrow Wilson was reelected President largely because “He kept us out of war”. But as the war unfolded in Europe, an intercepted telegram sent by the German Foreign Secretary, Arthur Zimmermann, to the Mexican government inflamed the U.S. public opinion and was one of the main reasons for the entry of the U.S. into WWI. This is the story of the encrypted telegram that changed the last century.

ORIGIN OF THE GERMAN OFFER

Germany was actively …read more

Voltmeter Speaks MQTT Without Libraries

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[Emilio Ficara] [built himself an Internet-connected MQTT multimeter](http://ficara.altervista.org/) (translated from Italian by robots). Or maybe we should say that [Emilio Ficara] undertook a long string of cool hacks that ended up in a WiFi-enabled multimeter, because the destination isn’t nearly as interesting as the voyage.

The multimeter, a DT-4000ZC, has a serial output but instead of transferring the data directly, it sends which cells on the LCD screen need to be activated. For testing along the way, [Emilio] used his own USB-serial-to-ESP01 dongle, which sounds like a useful tool to have around if you’re debugging an AT command session. He …read more

Friday Hack Chat: CircuitPython with Adafruit Engineers

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What the heck is CircuitPython? Get that question answered along with many more during this Friday’s Hack Chat. Three engineers from Adafruit join us as [Ladyada], [Tony DiCola], and [Scott Shawcoft] lead a CircuitPython discussion at Noon PST on 1/27/17.

CircuitPython is Adafruit’s new extension on the MicroPython codebase. It adds support for SAMD21 processors in MicroPython and reworks the API for better support across platforms and better documentation. Does this still sound like jibberish? The Python programming language has been extended to microcontrollers. CircuitPython is furthering that work and this Hack Chat is the perfect opportunity to talk with …read more

WS2812B LED Clones: Work Better Than Originals!

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Commodity electronics manufacturing is a tough game. If you come out with a world-beating product, like WorldSemi did with the WS2812B addressable RGB LED “pixel”, you can be pretty sure that you’re going to be cloned in fairly short order. And we’re all used to horror stories of being sold clones instead of what was ordered. But what if the clones were actually an improvement?

[Gonazar] bought some strips of “WS2812” LEDs and prototyped a project. When stepping up to larger production, he thought he’d go directly to WorldSemi. Long story short, the cheaper LED modules that he’d previously …read more

Pikelet – A Pi-Zero PC

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There are many uses for an old 10 Mbps Ethernet hub besides using it as a speed-bump in your network. (No fun in that!) [thinkerzone] decided to gut an old EN104 Bay Networks ‘Netgear Hub’ to re-purpose the solid steel case as a Raspberry Pi Zero PC housing. The project, which [thinkerzone] called Pikelet, aims to be an ‘IoT server’ with the feel of a PC. Note: a PC, not a Gameboy. In his hackaday.io project, he describes the minimum set of features for the Pikelet.

  • Power button – PCs need a power button
  • Power and Status LEDS – Blue

…read more

Pikelet – A Pi-Zero PC

See the original posting on Hackaday

There are many uses for an old 10 Mbps Ethernet hub besides using it as a speed-bump in your network. (No fun in that!) [thinkerzone] decided to gut an old EN104 Bay Networks ‘Netgear Hub’ to re-purpose the solid steel case as a Raspberry Pi Zero PC housing. The project, which [thinkerzone] called Pikelet, aims to be an ‘IoT server’ with the feel of a PC. Note: a PC, not a Gameboy. In his hackaday.io project, he describes the minimum set of features for the Pikelet.

  • Power button – PCs need a power button
  • Power and Status LEDS – Blue

…read more

WS2812B LED Clones: Work Better Than Originals!

See the original posting on Hackaday

Commodity electronics manufacturing is a tough game. If you come out with a world-beating product, like WorldSemi did with the WS2812B addressable RGB LED “pixel”, you can be pretty sure that you’re going to be cloned in fairly short order. And we’re all used to horror stories of being sold clones instead of what was ordered. But what if the clones were actually an improvement?

[Gonazar] bought some strips of “WS2812” LEDs and prototyped a project. When stepping up to larger production, he thought he’d go directly to WorldSemi. Long story short, the cheaper LED modules that he’d previously …read more

Tesla Vs. Edison

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The phrase “Tesla vs. Edison” conjures up images of battling titans, mad scientists, from a bygone age. We can easily picture the two of them facing off, backed by glowing corona with lightning bolts emitting from their hands. The reality is a little different though. Their main point of contention was Tesla’s passion for AC vs. Edison’s drive to create DC power systems to power his lights. Their personalities also differed in many ways, the most relevant one here being their vastly different approaches to research. Here, then, is the story of their rivalry.

Tesla’s Passion For AC

Nikola Tesla’s …read more

Voltmeter Speaks MQTT Without Libraries

See the original posting on Hackaday

[Emilio Ficara] [built himself an Internet-connected MQTT multimeter](http://ficara.altervista.org/) (translated from Italian by robots). Or maybe we should say that [Emilio Ficara] undertook a long string of cool hacks that ended up in a WiFi-enabled multimeter, because the destination isn’t nearly as interesting as the voyage.

The multimeter, a DT-4000ZC, has a serial output but instead of transferring the data directly, it sends which cells on the LCD screen need to be activated. For testing along the way, [Emilio] used his own USB-serial-to-ESP01 dongle, which sounds like a useful tool to have around if you’re debugging an AT command session. He …read more

Frankenquad takes to the air

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Modern quadcopter flight controllers perform a delicate dance of balancing pitch, yaw, bank, and throttle. They can do this thanks to modern MEMS gyros and accelerometers. The job is easy when the motors, propellers and speed controllers are relatively well matched. But what if they’re not? That’s the questions [SkitzoFPV] set out to answer by building Frankenquad.  Frankenquad is a 250 sized FPV quadcopter with 4 different motors and 4 different propellers. The props are different sizes from different manufacturers, and even include a mix of 3 and 4 blade units. If all that wasn’t enough [SkitzoFPV] used 3 different …read more

How To Sharpen Your Woodworking Tools On A Budget

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Wood may seem like a soft, weak material if you’re used to working with steel, but to do good work, you’ll quickly learn you need your tools sharp. Buying and maintaining a good set of tools can be expensive for the home gamer, so [shopbuilt] put together an Instructable on how to sharpen your woodworking tools on a budget.

The trick is to use sandpaper. It’s a good quality abrasive material and is readily available. You’ll want a selection of different grits – low grits to get started, higher grits when finishing. The reason this is cheaper is that you …read more

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