Vinduino: Full Irrigation With 25% Less Water

December 11, 2015 by 6 Comments

Irrigation is a fairly crude practice. Sure, there are timers, and rain sensors, but all in all we’re basically dumping water on the ground and guessing at the right amount. [Reinier van der Lee] wanted a better way to ensure the plants in his vineyard are getting the right amount of water. And this is Goldilocks’ version of “right”, not too little but also not too much. Southern California is in an extreme/exceptional drought. Water costs a lot of money, but it is also scarce and conservation has a wider impact than merely the bottom line.

His solution is the Vinduino project. It’s a set of moisture sensors that work in conjunction with a handheld device to measure the effect of irrigation. Multiple moisture sensors are buried at different depths: near the surface, at root level, and below root level. This lets you know when the water is getting to the root system, and when it has penetrated further than needed. The project was recognized as the Best Product in the 2015 Hackaday Prize, and [Reinier] presented the project during his talk at the Hackaday SuperConference. Check out the video of that talk below, and join us after the break for a look at the development of this impressive product.

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3D Printing On Shims?

December 11, 2015 by 24 Comments

Forget to generate support material for your 3D printed part? Already a few hours in? Don’t cancel the print — you might be able to save it!

[Dr Dawes] was printing a bunch of different parts for students in his electronics class. He slipped up and forgot to add support material to the one part that needed it. Figuring this out a few hours in, he didn’t have time to cancel the job and lose all the prints, so he made the best of the situation and paused the print to build his own support material. He ended up taping down index cards to the bed around his object until they reached layer 13 — the layer that would have started to bridge across the support material had he included it in his Octoprint settings.

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Hackaday Explains: Li-Fi & Visible Light Communications

December 11, 2015 by 62 Comments

A new way to transmit data is coming that could radically change the way that devices talk to each other: LiFi. Short for Light Fidelity, LiFi uses visible light to send data, creating the link between router and device with invisible pulses of light. This type of Visible Light Communication (VLC) uses something that is present in pretty much every room: an LED lightbulb.

What is LiFi?

Li-Fi sounds like the an engineer’s fevered dream: it is fast, cheap, secure and simple to implement. Speeds of up to 10Gbps have been demonstrated in the lab, and products are now available that offer 10Mbps speed. It is cheap because it can use a modified LED lightbulb. It is secure because it only works where the light is visible: step out of the room and the signal is lost. It is simple to implement because it uses an existing technology: LEDs.

The basis of the technology is in turning the LED light on and off very fast. By switching an LED on and off millions of times a second, you can create a data signal that can be detected by a sensor, but which is invisible to the human eye. At the other end, another LED detects these pulses, and can send light pulses back in response, creating a bi-directional link. If you combine this with wired Ethernet or a WiFi network, you have an awesome combination: an Internet connection that uses visible light for the last link.

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First Plasma In The World’s Largest Stellerator

December 11, 2015 by 89 Comments

If you’re looking for the future of humanity, look no further than the first plasma generated in the Wendelstein 7-X Stellerator at the Max Planck Institute for Plasma Physics. It turned on for the first time yesterday, and while this isn’t the first fusion power plant, nor will it ever be, it is a preview of what may become the invention that will save humanity.

A glimpse of plasma in side the Stellerator
A glimpse of plasma in side the Stellerator

For a very long time, it was believed the only way to turn isotopes of hydrogen into helium for the efficient recovery of power was the Tokamak. This device, basically a hollow torus lined with coils of wire, compresses plasma into a thin circular string. With the right pressures and temperatures, this plasma will transmute the elements and produce power.

Tokamaks have not seen much success, though, and this is a consequence of two key problems with the Tokamak design. First, we’ve been building them too small, although the ITER reactor currently being built in southern France may be an exception. ITER should be able to produce more energy than is used to initiate fusion after it comes online in the 2020s. Tokamaks also have another problem: they cannot operate continuously without a lot of extraneous equipment. While the Wendelstein 7-X Stellerator is too small to produce a net excess of power, it will demonstrate continuous operation of a fusion device. [Elliot Williams] wrote a great explanation of this Stellerator last month which is well worth a look.

While this Stellerator is just a testbed and will never be used to generate power, it is by no means the only other possible means of creating a sun on Earth. The Polywell – a device that fuses hydrogen inside a containment vessel made of electromagnets arranged like the faces of a cube – is getting funding from the US Navy. Additionally, Lockheed Martin’s Skunk Works claims they can put a 100 Megawatt fusion reactor on the back of a truck within a few years.

The creation of a fusion power plant will be the most important invention of all time, and will earn the researchers behind it the Nobel prize in physics and peace. While the Wendelstein 7-X Stellarator is not the first fusion power plant, it might be a step in the right direction.

Alfred P. Morgan: A Generation’s Radio Hacker

December 11, 2015 by 29 Comments

I was surfing the web looking for interesting projects the other day when I ran into [SkyKing’s] exquisite transistor demodulator radio builds. He mentioned that they were “Alfred P. Morgan-style” and that brought back a flood of memories about a man who introduced a whole generation to electronics and radio.

[Morgan] was born in 1889 and in the early part of the twentieth century, he was excited to build and fly an airplane. Apparently, there wasn’t a successful flight. However, he eventually succeeded and wrote his first book: “How to Build a 20-foot Bi-Plane Glider.” In 1910, he and a partner formed the Adams Morgan company to distribute radio construction kits. We probably wouldn’t remember [Morgan] for his airplanes, but we do recognize him for his work with radio.

By 1913, he published a book “The Boy Electrician” which covered the fundamentals of electricity and magnetism (at a time when these subjects were far more mysterious than they are today). [Morgan] predicted the hacker in the preface to the 1947 edition. After describing how a boy was frustrated that his model train automated to the point that he had nothing actually to do, [Morgan] observed:

The prime instinct of almost any boy at play is to make and to create. He will make things of such materials as he has at hand, and use the whole force of dream and fancy to create something out of nothing.

Of course, we know this applies to girls too, but [Morgan] wrote this in 1913, so you have to fill in the blanks. I think we can all identify with that sentiment, though.

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The Square Inch Project

December 11, 2015 by 7 Comments

For the last few years, Hackaday has been putting together some amazing contests. We gave away a trip to space, but the winner took the money instead. We gave away another trip to space, but those winners took the money instead. But we had a ton of fun along the way and are glad to see some others are getting in on the action. In September, a contest appeared out of the blue on hackaday.io. It is the Square Inch Project, a contest with the goal of stuffing the most electronics on a square inch of printed circuit board.

This wasn’t a contest designed, planned, or organized by anyone in charge here; this is a completely organic competition arranged and implemented by the hackaday.io community. A few months ago, a few notable hackaday.io people just decided to have a contest. Awesome.

OSHPark was kind enough to give out credits for PCBs as prizes, a we added in a few gift certificates to the Hackaday Store. Apparently that’s all you need to get a lot of people making a lot of cool stuff.

There are a lot of really great entries – far too many to cover in a single post – but you’ll find a few great ones below.

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Beautiful Sidewalk Graffiti Machine

December 11, 2015 by 22 Comments

Our hero [Alex] just built a sidewalk graffiti machine, and it’s a beauty to behold, so make sure you check out the video below the break. But don’t neglect [Alex]’s blog, and the build videos throughout. (Nice t-shirt in the wheel-making video, BTW.)

The machine itself is basically a two-meter wide printer where the roller is replaced with drive wheels. The frame, made of plywood, looks great and helps keep the machine light weight. Everything is done with DC motors and timing belts, which means motor encoders and closed-loop control in the firmware. It connects via a WiFi serial bridge, made with an ESP8266, to [Alex]’s cell phone.

Everything, from plans to software, is available on [Alex]’s GitHub for the project.

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