[Adam] made a remote camera trigger that uses a laser. He had to install CHDK on his camera, which we’ve featured in a how-to, in order for it to work. CHDK allowed for a remote shutter trigger through the USB port. The laser bounces off a mirror and onto the photoresisitor hooked up to an Arduino. When the beam is broken, the Arduino sets off the trigger. He also plans to use the trigger to tweet over ethernet. Embedded is a video demonstrating its functionality.
Already, both Rapid repair and ifixit have torn down the new iPhone 3G S, and phonewreck has provided some analysis. The new CPU runs twice as fast at 600 MHz and supports 720p video. They also found that the new 3 megapixel camera took better photos. Surprisingly, despite apple’s claims that the new phone has significantly better battery life, the battery itself has only 6% more capacity. Overall, not much has changed.
[Related iPhone 3G under the hood]
[Synoptic Labs] stumbled upon an RGB light strip with individually-controllable LEDs. The strip uses 5 volts and is controlled by an HL1606. Because the strips are hard to find, this chip is mostly undocumented and he had trouble driving the strip. He was unable to get it working until he met with [John Cohn], who had previously reverse-engineered the serial protocol. Working together, they released a library for the Arduino to drive the strip. So far, the library only supports fading each LED, the only known functionality. If more strips like these were available, constructing LED matrices would be much easier. Embedded below is a video of the strip fading through the rainbow.
[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]
[sprite_tm], whose projects we have covered in the past, took the popular bristlebot to an extreme and created a controllable version. A bristlebot consists of a small vibrating motor mounted with a battery on the head of a toothbrush. These micro-robots buzz around randomly, and he attempted to tame them. He used a platform of twin bristlebots and added an optical sensor from a laser mouse and an ATtiny13. The optical sensor is used to determine the relative motion of the robot, so that the motors can be adjusted accordingly. He also has a video of the bot using the sensor to find a mark on the floor and stay within bounds. Although it isn’t as accurate, it acts like a traditional line-following robot.
[Oomlout] has created an Arduino Experimentation Kit that uses basic sensors, buttons, and LEDs to teach electronics and programming. Printed overlays are secured on a breadboard, indicating components and connections. The Arduino is then used to drive the circuit. Examples include driving motors, using shift registers, and making beeps with a piezo element. These are backed up by explanations and code. The breadboarding kit is very similar to the classic 300-in-1 project kits marketed to beginners. In addition, all of the materials are released as open source. Kits are also available that include everything needed to create the circuits.
Related: Opensource Robotic Arm
[via Hack a Day flickr pool]
