[Alex] sent in a neat Ikea DIODER build that controls strings of RGB LEDs with HTTP requests.

We’ve seen Ikea DIODERs controlled wirelessly and over USB, but using the Internet with a DIODER is new to us. For his build, [Alex] used a Nanode, a small Arduino-like board that has built-in web connectivity.

The hardware portion of the build is very simple. A MOSFET controls each LED strip on the DIODER. The stock controller of the DIODER was ditched, meaning [Alex] needed to figure out how to convert an RGB color space to a Hue, Saturation, and Lightness color space “for super-classy fading.” Once that was figured out, [Alex] implemented a 1D Perlin noise function to blend between two colors.

Finally, the great EtherCard library was used to turn HTTP requests into dancing LEDs. [Alex] is thinking about building a JQuery webpage so he won’t have to muck around with entering commands like 192.168.1.25/hsl?i=0&h=135&s=90&l=50 into a browser. Without a nice web interface, it’s not as futuristic as [Alex] would like, but it’s still cool to us.

There are Kinect hacks out there for robot vision, 3D scanners, and even pseudo-LIDAR setups. Until now, one limiting factor to these builds is the requirement for a full-blown computer on the device to deal with the depth maps and do all the necessary processing and computation. This doesn’t seem like much of a problem since [wizgrav] published Intrael, an HTTP interface for the Kinect.

[Eleftherios] caught up to [wizgrav] at his local hackerspace where he did a short tutorial on Intrael. [wizgrav]‘s project provides each frame from the Kinect over HTTP wrapped up in JSON arrays. Everything a Kinect outputs aside from sound is now easily available over the Internet.

The project is meant to put computer vision outside the realm of desktops and robotic laptops and into the web. [wizgrav] has a few ideas on what his project can be used for, such as smart security cameras and all kinds of interactive surfaces.

After the break, check out the Intrael primer [wizgrav] demonstrated (it’s Greek to us, but there are subtitles), and a few demos of what Intrael ‘sees.’

[RSnake] has developed a denial of service technique that can take down servers more effectively. Traditionally, performing a denial of service attack entailed sending thousands of requests to a server, these requests needlessly tie up resources until the server fails. This repetitive attack requires the requests to happen in quick succession, and is usually a distributed effort. However, [RSnake]‘s new technique has a client open several HTTP sessions and keeps them open for as long as possible. Most servers are configured to handle only a set number of connections; the infinite sessions prevent legitimate requests from being handled, shutting down the site. This vulnerability is present on webservers that use threading, such as Apache.

A positive side effect of the hack is that the server does not crash, only the HTTP server is affected. His example perl implementation, slowloris, is able to take down an average website using only one computer. Once the attack stops, the website will come back online immediately.

Update: Reader [Motoma] sent in a python implementation of slowloris called pyloris

[photo: cutebreak]

If you are an Atmel fan, you may enjoy this webserver built around the ATmega88. Since it has full TCP and HTTP support, communication can be done using a standard web browser on any system. We also noticed that the code uses AVR Libc and the processor can be replaced with an ATmega168, both used on the Arduino platform. Honestly, we think the most interesting part about this project is the firmware. The author has assumed that the webserver will only be sending one packet per request and the code is optimized for this setup. This leaves around 50% of the memory for the web application.

[via YourITronics]