Author: Al Williams

4504 Articles

This SDR Uses A Tube

March 7, 2019 by 17 Comments

When you think of a software defined radio (SDR) setup, maybe you imagine an IC or two, maybe feeding a computer. You probably don’t think of a vacuum tube. [Mirko Pavleski] built a one-tube shortwave SDR using some instructions from [Burkhard Kainka] which are in German, but Google Translate is good enough if you want to duplicate his feat. You can see a video of [Mirko’s] creation, below.

The build was an experiment to see if a tube receiver could be stable enough to receive digital shortwave radio broadcasts. To avoid AC line hum, the radio is battery operated and while the original uses an EL95 tube, [Mirko] used an EF80.

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Raspberry Pi Camera With Smarts — Cloud Or Local?

March 7, 2019 by 20 Comments

[Mark West] gave an interesting presentation at last year’s GOTO Copenhagen conference. He shows how he took a simple Raspberry Pi Zero webcam and expanded it with AI. He actually added the intelligent features in two different ways: on in the Amazon cloud and another using the Intel Modvidius NCS USB stick directly connected to the USB. You can see the video below.

Local motion detection uses some open source software. You simply configure it using a text file and it even handles the video streaming. However, at that point, you just have a web camera — not amazing, nor very cost effective. However, you get a lot of false alarms with the motion detection software. A random cat walking past, clouds, trees, or even rain would push [Mark] an email and after 250 alert e-mails a day, [Mark] decided to make something better.

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Joulescope DC Energy Analyzer Reviewed

March 6, 2019 by 29 Comments

[VoltLog] got a hold of a prerelease unit of Joulescope — a DC energy analyzer that promises to make it easy to optimize power and energy usage of your electronic designs. You can find his review in the video below. The device is a very fast ammeter and voltmeter. Given that, it is easy to compute energy and, over time, power.

The device is set to retail for about $400 according to a letter in the video, although the website mentions closer to $800. Both of those seem to be a bit much for a piece of specialty gear that is really just a fast analog to digital converter and some software. To be fair, the device can read ranges between 18 microamps to 10 amps with resolutions as low as 1.5 nanoamps on the lower side of the range. Is it worth it? That will depend on your application and your price sensitivity.

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The Strangest Gameboy Emulator We’ve Seen Yet

March 6, 2019 by 16 Comments

In the secret Hackaday bunker, we have some emacs users, some vi users, and some people who don’t really care. However, even the staunchest of our emacs supporters had to do a double take at [Vreeze’s] project that creates a GameBoy emulator using the venerable text editor. You can see [Alexei Nunez’s] reaction to the emulator in the video below.

The Eboy uses unicode characters to output the graphics. You can use emacs commands to load ROM images and use your keyboard to control the game.

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Tech Imitates Life: Fireflies Make Better Light Bulbs

March 5, 2019 by 46 Comments

While we often think we are clever designers, living things often meet or beat the best human designs. It is easy to forget that nature even has living lightbulbs, among them the firefly. Researchers from Penn State decided to compare how fireflies create light and found that they deal with a problem similar to LEDs. The insight may lead to an increase in efficiency for LEDs, which is currently about 50%.

The problem is that some light generated never gets out of the LED (or the firefly’s body). Some light inevitably reflects back into the device. One known mitigation for this is creating a tiny texture pattern on the LED surface which allows more light to escape. These are typically a V-shaped structure etched into the surface. This isn’t news to the firefly, however, which has similar structures on their lanterns as do some other light-generating animals (apparently glowing cockroaches are a thing). However, the organic structures differ from LED textures in an important way.

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Better Living Through Science: Why Your Kids Probably Aren’t Getting Measles

March 5, 2019 by 153 Comments

Oddly, there’s been a few recent outbreaks of measles. It struck me how when I was a kid, a few hundred kids getting measles wouldn’t have been news at all. However, even a handful makes the news now, since in 2000 the Center for Disease Control declared measles eradicated in the United States.

So how can an eradicated disease come back? How did we eradicate it to start with? The answers tell a pretty interesting tale of science applying to everyday life.

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Reducing Carbon Emissions With Coal

March 4, 2019 by 112 Comments

It might seem like a paradox, but coal might hold the answer to solving carbon emission problems. The key isn’t burning it, but creating it using carbon dioxide from the atmosphere.  While this has always been possible in theory, high temperatures make it difficult in practice. However, a recent paper in Nature Communications shows how a special liquid metal electrocatalyst can convert the gas into a solid form of carbon suitable for, among other things, making high-quality capacitor electrodes. The process — you can see more about it in the video below — works at room temperatures.

It isn’t that hard to extract carbon dioxide from the air, the problem is what to do with it. Storing it as a gas or a liquid is inefficient and expensive, while converting it to a solid makes it much easier to store or even reuse for practical applications.

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