I'm working on an inertial navigation system for an autonomous aircraft. An Arduino Mega communicates with an inertial measurement unit (six degrees of freedom, 3-axis gyros, 3-axis accelerometers), a 3-axis magnetometer, static and differential pressure sensors (altitude and airspeed respectively), ultrasonic rangefinder (for very precise landing altitudes), and a 5Hz GPS.

I just completed a first flight which limited the scope of the test to a glider that kept the wings level and the nose on the horizon (using the pitch and roll data from a Kalman filter running on the IMU data updated at about 54Hz). Here's what that system looks like: http://www.flickr.com/photos/ttrueman/3770700718/

It's a lot of fun and I highly recommend Arduino hacking to anyone that wants to give hardware a try.

Here's a good starter kit: http://www.sparkfun.com/commerce/product_info.php?products_i...

One simple project that seemed cool to me was this LED one: http://blog.bsoares.com.br/processing/controlling-rgb-led-wi...

If you're ambitious you could try building your own UAV based on Arduino using Ardupilot: http://diydrones.com/profiles/blogs/ardupilot-main-page

(I know this comment goes on and on but if you work with i2c, SPI or serial often check out Saleae's Logic: http://www.saleae.com/logic/ which is a cheap logic analyzer that is incredibly useful and well done.)

That sounds really amazing. I'd love to build an autonomous solar powered glider someday and have it just fly all over the world sending back data.

I guess we just need really lightweight batteries first so it can make it through the night. It could seek out free wifi hotspots to use to report the data back to me.

First off, it couldn't be a glider, if you wanted it to do that. Secondly, a balloon might be a better option.

Thirdly, http://www.thevlecks.net/rmj/earth.html It could keep up with the sunlight, if developed to be fast enough.

Lastly, I would look into APRS as a better alternative to free wifi, in this situation.

You should check out my friend Nikolaj's project page. He has done a load of RC and electronics projects that are along the same lines. They are documented here. http://dzl.dk/projects/index.html

There are a few tesla coil projects too that are kind of fun :-)

I'm building a 5' stage backdrop for performing (I'm a singer/songwriter) using the ledstrip Arduino library (http://code.google.com/p/ledstrip/) and 15' of lights I bought from coolight.com.hk.

So far I have a little electret microphone hooked up to it and I have the lights reacting when I sing into it. I'm still working out how I want them to react in the final version (changing colour + speed/intensity), then I'm going to hook it up to a foot pedal as well so I can trigger it selectively (e.g., during the chorus of a couple songs) and build the actual backdrop setup.

The Arduino is really fun. After this I'm going to try my hand at custom guitar pedals and maybe a theremin.

I was rather interested in Arduino for a long time (having grown up tinkering with Parallax's BASIC Stamp ][), and ended up ordering the projects kit from MAKE last month. I also got a "max m" rgb led array and am planning to make an ambient information system.. In a sense I just have this thing chilling in the corner of my room and depending on color and brightness it will convey to me different types of information. I still have to get the ethernet controller, but likely it will check for new users on my web app and if we get a lot turn red, etc... or check my gmail. one of those.

http://www.flickr.com/photos/pauls/3710500813/

I've been making the feelSpace belt with an Arduino Pro Mini: http://feelspace.cogsci.uni-osnabrueck.de/en/technology_01.h...

However, I haven't been able to find a cheap source of tiny vibrating motors (e.g. pager motors), so the project's at a standstill right now.

Is $4.95 cheap enough? http://www.sparkfun.com/commerce/product_info.php?products_i...

For anyone that hasn't heard of Sparkfun, it's kinda of like a small Newegg for electronics projects.

I actually bought one of those to try it out back when I started the project. But the price was more like $1.50 from the place I bought it from (RobotShop). Since then, the price has gone up, so I feel ripped off at five bucks, eheh.

Here are two sources:

http://cgi.ebay.com/Pager-Vibrator-Motor-Bristlebot-Robot-Be...

http://www.pagermotors.com/index_files/Products/DiskL/DiskL....

(Don't feel bad, searches come up with nothing!) I was reading unrelated blog posts to find these.

By the way, I'm going to try building a feel space belt soon, you should email me.

Hey, thanks for the links. Only problem is, I'm Canadian, and it's tricky to find people who will ship to me...

But yeah, if we could get a bulk order in together that would be great!

I'm currently building a media center, and I'm using an arduino-derived board to control an LED display on it. I'm short-sighted, but don't wear my glasses much, so I wanted a big bright screen to do track listings and look pretty. Plus it only cost £35!

In my school's product realization class my team built a prototype of a portable device used for a specific type of genetic testing, LAMP.

Got any links to documentation?

Ultimately what we did with the Arduino itself wasn't that interesting (read sensor, adjust heater, trigger some lights) but if you'd like to read our report send me an email and I will forward it to you.

I got one a few months ago and just started doing baby projects. Here's my first project: http://www.blendedtechnologies.com/realtime-plot-of-arduino-...

It's just a knock sensor that prints a plot of the knocks to the screen. a "poor man's oscilliscope" sort of.

My next project is a variation on this haptic ultrasonic hat: http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects...

I'll post it a writeup if anyone's curious.

I've been keeping an eye on Jon Oxer and Hugh Blemings as they put together 'Practical Arduino' - they're up to lots of cool stuff:

http://www.practicalarduino.com/

http://twitter.com/jonoxer

http://twitter.com/hughhalf

Also, teensy board projects would be nice to know about.

I hooked an old PS2 wedge barcode reader up to a Sanguino, so that it could store a bunch of barcodes, and dump them into LibraryThing.

Also see: http://news.ycombinator.com/item?id=637804