Hackaday Links: December 13, 2015

So you’ve been rocking a tin foil hat for years now, and people have finally gotten used to your attire and claims that fluoridated water is a government mind control experiment. This holiday, how about something a little more stylish? Yes, it’s a Kickstarter for the World’s First Signal Proof Headwear. This fashionable beanie or cap protects you from harmful electromagnetic rays. Next time you shoot an eighteen minute long YouTube video of a wheezing rant about chemtrails, look fashionable with Shield – the world’s first stylish signal proof hat.

That last tip came to us from a Crowdfunding marketing agency. That means money was exchanged for the purposes of marketing a modern tin foil hat.

[Mike] has an old IBM 5155, the ‘luggable’ computer with design cues taken from the first Compaq. With an Ethernet adapter and a little inspiration, He was able to get this old computer to load the Hackaday retro edition.

[gyrovague] has a Chromecast that’s a bit janky. When it comes to electronics, strangeness means heat. The solution? A heat sink for the Chromecast. You don’t even need a proper heat sink for this one – just epoxy a big ‘ol transformer to the aluminum plate in the Chromecast.

This year, Keysight gave away a pile of test and measurement gear to the i3Detroit hackerspace. Keysight is doing it again, with a grand prize of around $60,000. Entries close on the 15th. Protip: you, personally, don’t want to win this for tax reasons. A non-profit does.

The Internet recently caught wind of a satellite modem being sold by Sparkfun. It’s $250 for the module, with a $12/month line rental, and each 340 byte message costs $0.18 to receive. Yes, it’s cool, and yes, it’s expensive. If you ever need to send a message from the north pole, there you go.

Need to remove the waterproof coating from LED strips? Don’t use a knife, use a Dremel and a wire brush.

Hackaday Links: December 6, 2015

[Camus] had it all wrong. After a few hundred years of rolling a stone up a mountain, Sisyphus would do what all humans would do: become engrossed in novelty. The stone would never reach the summit, but it could roll off some pretty sweet ramps. That mountain goat that ticked him off a few decades ago? If Sisyphus let go right now, the stone would probably take that goat out. Sisyphus, like all of us, would be consumed in meaningless novelty. One must imagine Sisyphus happy.

The pumpkin spice must flow. It’s the holidays and for a lot of us that means copious amounts of baked goods. How about an edible sandworm? It looks like something close to a cinnamon roll.

This December’s Marie Claire – whatever that is, I have no idea – features haute circuits. These circuit boards are the work of [Saar Drimer] and Boldport, makers of fine circuit board art. We’ve seen his work a number of times featuring squiggly traces and backlit panels. This seems to be the first time Boldport and the entire idea of PCB art has infiltrated the design world. He also does puzzles.

Raspberry Pi cases simply do not look cool. There’s ports coming out everywhere, and plastic really doesn’t look that great. You know what does look great? Walnut. [Karl] made a few of these out of walnut, MDF and solid aluminum. He’s thinking he might bring this to market, you can check out his webzone here.

Self-driving cars being sold right now! That’s an eBay link for a DARPA Grand Challenge vehicle, a heavily modified Isuzu VehiCross loaded up with computers, a laser scanner, camera, and connected to actuators for steering, brake, pedals, and shifter.

A few years ago, a snowboarding company realized they could use YouTube as a marketing device. They made some really cool projects, like a snowboard with battery-powered heaters embedded in the core of the board (yes, it works). There’s only so many different snowboards you can build, so they turned to surfboards. In fact, they turned to cardboard surfboards, and last week they made a cardboard electric guitar in the Fender custom shop. It’s a completely understandable linear progression from A to B to I don’t know what kind of glue they’re using.

Radio Receiver Build Log and More

At Hackaday, we like to see build logs, and over on Hackaday.io, you can find plenty of them. Sometimes, though, a builder really outdoes themselves with a lot of great detail on a project, and [N6QW’s] Simple-Ceiver project certainly falls into that category. The project logs document many different stages of completeness, and we linked the first one for you as a starting point, but you’ll definitely want to read up to the present. (There were 16 parts, some spanning multiple posts, last time we checked).

It is definitely worth the effort though. The project started out as a direct conversion receiver, but the design goes through and converts it into a superheterodyne receiver. Along the way, [N6QW] shares construction techniques, design advice, and even simulation plots (backed up with actual scope measurements). The local oscillator, of course, uses an Arduino and an AD9850 synthesizer.

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Imagination Not Necessary With This Helicarrier Bed

We think we have another dad-of-the-year award to give out. When [Andy’s] five-year-old son won a Raspberry Pi 2 and needed a new bed, they decided to build the ultimate bed. It’s loosely based on the Helicarrier from S.H.I.E.L.D. and it’s packed with so much tech, you barely need to imagine anything to have fun with it.

It looks pretty simple from the outside, until you realize that the detailed little hatch on the side is actually a keypad secure entry automatic sliding door. Controlled by the Raspberry Pi, recordings of [JARVIS’] voice speak to you as you enter the belly of the ship, er, bed.

imag1813Inside are glowing display cases featuring some of his son’s favorite Marvel superhero’s equipment — ready for use. But what’s really cool is the command console.

The terminal is expertly crafted to look like something out of the movies, and with the Raspberry Pi 2, his son can play with it and fight off the bad guys. There’s even a sentry turret with camera on the outside, controlled from inside the bed.

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Polyakov Direct Digital Synthesis Receiver

Direct conversion receivers are popular among ham radio operators and others who build radios. Suppose you want to listen to a signal at 7.1 MHz. With a direct conversion receiver, you’d tune a local oscillator to 7.1 MHz, and mix it with the incoming signal. The resulting sum and differences of the input frequencies will include the audio of an AM signal on the desired frequency.

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Act Now And Receive the Prong Saver For Only $0.00!

Well, actually, you can’t buy this. But for [TVmiller’s] latest project he decided to have some fun with the video — so he made an infomercial for it.

Called the Prong Saver, the device clips onto any appliance’s electrical cord to help prevent you from accidentally pulling too hard and bending the electrical prongs. It’s basically a cord-tension alarm. The question is — can you hear it over the vacuum cleaner?

And just because he could, it’s solar powered. Because why the heck not? He built it using scraps he found around the workshop. That included a solar powered LED key chain, a small piezo speaker, an eyebolt and a compression spring. Anyway, check out the commercial after the break. It had us in stitches.

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Your First GNU Radio Receiver with SDRPlay

Although GRC (the GNU Radio Companion) uses the word radio, it is really a graphical tool for building DSP applications. In the last post, I showed you how you could experiment with it just by using a sound card (or even less). However, who can resist the lure of building an actual radio by dragging blocks around on a computer screen?

For this post and the accompanying video, I used an SDRPlay. This little black box has an antenna jack on one end and a USB port on the other. You can ask it to give you data about a certain area of the RF spectrum and it will send complex (IQ) data out in a form that GRC (or other DSP tools) can process.

The SDRPlay is a great deal (about $150) but if you don’t want to invest in one there are other options. Some are about the same price (like the HackRF or AirSpy) and have different features. However, you can also use cheap TV dongles, with some limitations. The repurposed dongles are not as sensitive and won’t work at lower frequencies without some external help. On the other hand, they are dirt cheap, so you can overlook a few little wrinkles. You just can’t expect the performance you’ll get out of a more expensive SDR box. Some people add amplifiers and converters to overcome these problems, but at some point it would be more cost effective to just spring for a more expensive converter.

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