Hackaday Links: October 6, 2012

October 6, 2012 by Brian Benchoff 33 Comments

Upgrading a desktop with a diamond cutting wheel

[Michail] needed a new graphics card. The only problem was his motherboard didn’t have any free PCI-E x16 slots available. Unable to find a PCI-E x1 card, he did what any of us would do and broke out the Dremel. Yes, he got it working, but don’t do this unless you know what you’re doing.

It’s recycling!

[Steve] recently got a Galaxy S3 and was looking for something to do with his old phone. It’s got WiFi, it’s got a camera, and with a free app, [Steve] now has an IP Webcam. Neat way to recycle a phone.

This is now bookmarked

We’re not much for plugging other blogs, but Math ∩ Programming – that’s intersection, remember – is really cool. Apparently it has been around for a little more than a year and already there are quite a few really cool posts. How to use cellular automaton to generate caves in video games and facial recognition through Eigenvalues are amazingly in depth, and show the theory behind some really cool techniques. Very, very cool.

Troll Physics: now wireless!

Remember [Fredzislaw100], the guy who puzzled the Internet with impossible circuits? He’s back again, this time with wireless LEDs. We’re guessing something similar to an induction charging system in the battery clip, wirelessly coupled to something under the paper, and that is wirelessly coupled to the LEDs. Your guess will probably be better than ours, though.

Not shown: Captain Obvious, Major Major

Pv2 [Zachary Ricks] of the U.S. Army thought we would get a kick out of the last name of one of the guys in his company. Yes, it’s ‘Hackaday,’ and yes, it’s a real surname. Here’s the full pic [Zach] sent in. Apparently it’s a name along the lines of ‘Holiday.’ Honestly, we had no idea this was a real surname, but we’re thinking Private Hackaday could use a care package or two (dozen).

Anyone up for sending a few hacker friendly (for [Zach] and a few other guys) care packages? Even socks or books or Oreos would make for an awesome care package. Email me if you want the mailing address.

Hackaday-proofing Your Hackerspace’s Server

October 6, 2012 by Brian Benchoff 24 Comments

Last month we posted a tutorial from Hub City Labs on making your own PCBs at home. At the time, Hub City was hosting their hackerspace web site on a tiny vps graciously provided by a member. As you might expect, the throngs of Hackaday readers turned Hub City Labs’ server into a pile of molten slag and made their admin’s hair a little more gray. Their web site is up again, and Hub City provided a tutorial on protecting your server from the ravages of being Slashdotted, Farked, Reddited, and even Hackaday’d.

The solution for the first few hours was to transfer Hub City Labs’ site to an Amazon EC2 instance. Since then, they’ve moved over to a Debian EC2 instance that is able to handle half a million pageviews an hour for a WordPress site.

This amazing capability required a good bit of optimizations. A WordPress installation is set to run cron tasks on every page load; not good if you’re going to see thousands of hits every minute. The guys added define(‘DISABLE_WP_CRON’, true) to their wp-config.php file and set all the background tasks – checking to see if a page should be updated – to a fixed schedule every minute or so. Along with an increase in the WordPress cache, these optimizations increased the number of pageviews an hour from 1500 to 60000.

To get up to half a million pageviews an hour, the EC2 instance was loaded up with Varnish, a front-end cache that really speeds things up.

The result – 375 million pageviews for $15 a month – is more than Hub City Labs will probably ever need. The nature of hackerspace web sites, though – light load until Hackaday, Slashdot, or Reddit figure out you did something cool – means hosting on an expandable EC2 instance is probably the way to go.

Web IDE For The Raspi

October 6, 2012 by Brian Benchoff 9 Comments

For this month’s release of Adafruit’s Raspberry Pi Linux distribution, [Limor], et al. decided to build a web-based IDE for the Raspberry Pi.

The Raspberry Pi WebIDE is a web server that runs on the Raspi. By connecting to your raspi in a web browser, you’re able to create your own Python programs that are able to interact with the GPIO pins. All the code is stored in the cloud with the help of bitbucket.

The WebIDE is in its early Alpha stage right now; there are a few bugs and minor issues, but in the video after the break, [Limor] shows us it’s possible to push code to a Raspi through the Internet and view the result in a web-based serial terminal.

For fear of editorializing, we have to point out that Adafruit’s web IDE – along with other Arduino web IDEs such as Codebender and the Wifino – work on the cloud. If you’re planning a long-term project that relies on a web-based IDE, you might be in for a world of hurt if only because you can’t host a cloud on a personal server. We’d love to see a package that allows us to have the same functionality as bitbucket on a personal server. If you can find a project that does something similar, or have written your own, send it in and we’ll spread the word.

Continue reading “Web IDE For The Raspi” →

Flashing LEDs Protect Livestock From Lion Attacks

October 6, 2012 by Ryan Fitzpatrick 50 Comments

When we think of defense against lion attacks, the first thought is usually guns. Lots and lots of guns. [Richard Turere], a 13 year old Kenyan tinkerer with neither books nor any technical education, has come up with something entirely different – He’s keeping the lions at bay with a solar powered system of flashing LEDs. Yup. Flashing LEDs.

Since he and his family live next to Nairobi National Park, lion attacks are an ever present danger. The only defense systems available were far too expensive for his family to afford, so he decided to build his own. He utilized the basic resources he had readily available: LED bulbs removed from broken flashlights, some switches, an old car battery, wire, and a solar panel that also operates his family’s TV.

The results speak for themselves. His family has had no lion attacks in over two years, and at least five of his neighbors believe in the system enough to have had him install it on their fences too. With the cost for this set up at less than ten dollars, and all the parts being readily available, this rather basic electrical system is an amazing breakthrough for the Kenyan pastoralists.

We look forward to seeing more of [Richard’s] inventions. Way to go!