Hackaday Gathering: Shanghai

March 11, 2014 by Mike Szczys 5 Comments

Does Hackaday have any readers living in Shanghai? You bet! We’re going to be in Shanghai next week so we decided to invite the Hackaday community to a Shanghai Gathering!

We booked a venue and want to pack the place with at least 150 people on Thursday, March 20th. We’re picking up the bar tab and bringing along a few cases of T-shirts. At some point we’ll make some formal remarks about the path on which Hackaday is traveling, and where we hope to go. Get your tickets now, and start the perplexing process of deciding which piece of portable hacked hardware you want to bring along with you to show off to all of the other Hackaday aficionados.

Still not convinced? Check out the follow-up post from our Los Angeles Gathering back in January to see how much fun it is to get together with other readers. The Xin Che Jian hackerspace in Shanghai is helping us get this organized; we saw a hackerspace intro from them a couple of years back. Thank you so much to [David] and [Paul] for their help with this! If you haven’t checked out the hackerspace, this gathering is a great way to meet some of the members.

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Retrotechtacular: Shedding Light On Holograms

March 11, 2014 by Kristina Panos 10 Comments

This week’s Retrotechtacular is a 1972 introduction to holography produced by the fine folks at Encyclopædia Britannica. It details quite admirably what holograms are and how they’re made.

Holograms are quite different from photographs, though both are recorded on film. Holography is based on the additive effects of waves: two crests of equal amplitude create a larger crest, while a crest and a trough of equal amplitude cancel each other out, causing an interference effect. The video demonstrates the concept nicely with water ripples and explains that the same effect happens with sound waves and light waves.

Lasers are the key to the intense and spectrally pure light required for holography. Incandescent light consists of too many wavelengths to be effectively split into two identical light wave sources. To create a hologram, a laser is split with an optical device into two beams. One beam is focused directly on the object being recorded and is called the object beam. The second beam is directed away from the scene through a series of mirrors and shone directly onto a film emulsion.

The film records the interference between the waves of the two beams. It appears to be blank after development, but upon close inspection reveals stripes of light and dark. When the exposed film is placed in the path of only the reference beam, the interference patterns recorded on the film split the beam back into two, recreating the scene. With the aid of a screen for projection, the hologram can be seen showing the original object in 2D. Another big difference between photographs and holograms is that even a small portion of a hologram can reproduce the entire scene, but a piece of a photograph is just that.

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Sci-Fi Contest Prizes Make You Drool Like A Rancor

March 11, 2014 by Mike Szczys 61 Comments

It’s been awhile since we hosted a contest, now is the time to up our game. You have a few weeks to come up with the best Sci-Fi themed hack. We’ve amassed a number of prizes well worth fighting for, and the challenge will be won by a combination of clever, collaborative, and open. The booty includes rad (yeah, we said it) tools like Oscilloscopes, Logic Sniffers, Solder Stations, and Dev Boards, as well as themed offerings like classic Sci-Fi films and tchotchkes from our favorite fictional universes.

Yesterday we announced that Hackaday Projects is open for public registration and now we’re taking the new site for a spin. Previous contests like the Trinket and Fubarino versions became unwieldy for the Hackaday crew just because of the sheer volume of entries. The new interface will make it much easier. We also want to test out the collaborative features so one of the requirements for entry is to participate as a team. The winners will be picked based on how well the project is documented, how open (as in software and hardware) it is, how it fits the theme, and on how well the team worked together.

The contest starts right now and ends at 12:00:00am Pacific time (we know a lot of you like to push deadlines) on April 29th, 2014. Head over to the contest page to see all of the details. Let the games begin!

[Official Contest Page]

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Automated Light Painting Makes It Easy

March 11, 2014 by James Hobson 10 Comments

What can we say — we’re a sucker for projects that feature our favorite logo. This is the Parallax Propeller Automated Light Painting Machine — and no, it’s not a persistence of vision setup.

[Daniel], [Nathan], and the folks over at Embedded Aesthetics are big fans of Hack a Day and are very excited to share their new project. It’s a fully automated light painting setup that features an X-axis slide, a strip of RGB LEDs, a Parallax Propeller (microcontroller), and a DSLR — all you have to do is choose an image, and press start.

They first started light painting with their LED Paint Brush, an equally awesome, but slightly less automated tool. They’ve created this one to be a bit more interactive — in fact, you can actually go on their website, upload an image, and it will paint you a picture! But… it’s not available right now.

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Smart Kegerator Bills Based On Beer Consumption

March 11, 2014 by Kristina Panos 34 Comments

Kegerator ownership is awesome, but it has its downsides. It’s hard to keep track of who drank what without cans or bottles to count. [Phil] was looking for a good solution to this problem when it came to sharing beer with his roommates and friends and has just completed the first iteration of his smart kegerator.

He has devised a system based on a Raspberry Pi. His software recognizes the face of the person pulling a beer and adds a charge to their tab based on the price of the keg and the volume of the pour. The system also keeps track of current and historic temperature and humidity values inside the kegerator, and everything is displayed on a Mimo 720S touch screen.

[Phil] has a flow meter on each keg to detect and monitor pouring. This triggers the Pi camera module to run the facial recognition. The walk-through found after the jump might be a bit confusing; at the time it was recorded, the unit was only capable of facial detection. [Phil] wrote the UI in QT and C++ and used Python scripts for the flow interrupts. His plans for future iterations include weight sensors underneath the kegs, liquid probe thermometers for more accurate beer temperature readings, a NoIR Pi camera module for low light conditions, and a really snazzy UI that you’ll see on his build page.

If you don’t have a Pi, here’s an Arduino-fied kegerator that reports temperature and controls beer cooling.

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Remote Shutter Release Lets You Be A Hipster From A Distance

March 11, 2014 by James Hobson 19 Comments

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So, you’re taking high resolution photos with your ancient medium format film camera — but you can’t be at the camera. Well, if you’re [curlyfry562] you build your own remote controlled mechanical shutter release!

Due to the age of the film camera, there really aren’t many (or… any?) off the shelf solutions to this problem. Especially not with the list of project goals [curlyfry562] came up with:

It must be triggered by a remote TTL signal
The wireless range must be at least 100ft
It has to be reliable — medium format film is expensive!
It needs to be easily mountable and removable

With his goals clearly set, he began work. He’s using 2.4GHz xBee modems which have a DIO pin — if you link up two for DIO line passing, then they act as clones of each other — change the state of one, and the other one follows. Using this he’s wired up the output to a microcontroller, which than powers a servo to depress the mechanical shutter release. It’s actually quite brilliantly simple.

If you don’t need quite as much range — check out this remote shutter release made from a wireless doorbell!

[Thanks Daniel!]

Missing Drone Posters Are A Hilarious Look Into The Future

March 10, 2014 by James Hobson 86 Comments

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Sure there are reward posters for missing cats, dogs, and other various pets — but now in Denver, a man named [Merrick] makes a plea for his $2400 missing drone.

We couldn’t help but chuckle at this news story because it could be the tip of the iceberg. As drones become more and more common place, seeing missing posters for them could become pretty normal! The problem is, when you’re using a long-range drone, and flying it in a city, it is very possible to lose your line of sight and lose the device altogether. That is exactly what happened to poor [Merrick] the other day. Thinking quickly, he started making lost drone posters, and after channel 7 news reported on it, it was discovered in an alleyway the following day. The person who found it thought it was government related and didn’t want to mess around with it — it’s a pretty serious looking drone. Continue reading “Missing Drone Posters Are A Hilarious Look Into The Future” →