Hacking A Scale To Test Rocket Motors


[David Steeman] sent us this project. He uses a consumer scale to measure rocket engine thrust. He wanted to be able to map the thrust curve of his homemade rocket motors to determine whether they are meeting the design goals. It does this by measuring the force applied by the rocket engine via a microcontroller that records it in a text file on a computer. He then analyzes this data in an Excel spreadsheet.

The sensors were harvested from a consumer scale while the rest of the electronics were built by hand. He’s using a PIC 18F2550 microcontroller which has a built in USB interface. He has breakdowns of each piece with detailed information on how it works as well as some nice pictures. There is also a list of future improvements that he would like to do such as increasing sample speed, integrating it with the ignition, and decreasing the physical size. Files for the schematic, firmware, and excel spreadsheet are available for download at the bottom of the page, so keep scrolling down.

Aurora Mixer Now Available


It’s been a long time coming but that highly sought after open source mixer, the aurora224 is now available for purchase on the company’s website. The aurora mixer is a fully programmable USB mixer complete with 24 back lit knobs, 2 faders, and a single crossfader.

While the instructions on how to assemble your own mixer from scratch have been available for sometime now, many wanted a kit complete with everything needed to avoid having to source the parts themselves.

The aurora mixer is available in 2 versions, a fully assembled turn key deck and a DIY kit that requires the use of a soldering iron and the ability to follow directions.

So, if you’ve wanted to build your own aurora mixer but never knew where to start, this may be your lucky day. Don’t wait too long as you have until September 1st to get your order in.

Wifi Robot : A Hacked WRT54GL Rover

[Jon Bennett] sent us this link to his Wifi Robot. After playing with a Linksys WRT54GL router, he was inspired to build something that would utilize this embedded Linux system. Using a thrift store R/C truck, he built a wireless robot rover. This thing can be controlled over the internet, or by laptop with a range of about 500 meters.

The router has been modified to have 2 Serial ports and a 1GB SD Card. It connects to a micro controller, which could be an Arduino or AVR Butterfly. He has supplied information for both. The truck has been mostly gutted, leaving only the chassis and electronics. He had to beef up some of the truck electronics when they fried under the load. The entire unit is powered by a pair of 7.2 Volt 3800 mAh battery packs. The most important thing on the list though, is the horn. You can honk the horn while you are driving this thing around.

The site supplies tons of information including pictures of his build, videos of it in action, speed tests, schematics, software downloads, and resource links. Great job [Jon].

Create Your Own Playlist Hosting Service With Opentape


While Muxtape takes a breather to resolve an issue with the RIAA, Lifehacker has a step by step guide on installing and running Opentape, an open source PHP web application that’s similar to Muxtape. Take matters into your own hands and create your own version of playlist hosting heaven. Since Opentape is open source, you can adapt it and make it an even better application. Maybe your creation will be even more popular than Muxtape… and will lead to the same problems with the RIAA.

Testing IR Camera Blocking

[youtube=http://www.youtube.com/watch?v=0u5hAfnq2-4&hl=en&fs=1&rel=0][randy] from F.A.T. tested the theory that infrared LEDs can actually hide you from the prying eyes of surveillance cameras. We’ve previously covered camouflage, IR, and other suggestions for eluding the cameras, but haven’t taken to sewing stuff onto our clothes yet. [randy] lined his hoodie with high-intensity infrared LEDs, hoping to create a halo effect that would hide his head, and tested his results. Unfortunately, his efforts were unsuccessful. He tested many many different combinations and we’re confident in his conclusion that it would be very hard to make this work.