The gist of the idea is to suspend an underwater tunnel from floating pontoons. By the time you finished reading that sentence, you probably already had a list of things in your head that seem to make this a terrible idea. After all, it does seem to combine the worst aspects of both underwater tunnels and bridges. But, the idea may actually be a good one, and it’s already being seriously considered in Norway.
[eN0Rm’s] Raspberry Pis are much more than just another brick in the wall. He’s used the popular embedded Linux platform to build several small rear projection screens in a brick wall (Imgur link). Brick shaped metal enclosures were mortared into the wall of the building. Each rear projection screen is illuminated by a DLP projector which sits inside the metal enclosure. The Raspberry Pis sit on a shelf below all this. The bricks are in a building in the Aker Brygge section of Oslo, Norway, and show historical facts and short videos about the local area.
[eN0Rm] could have used a PC for this task, the price for a low-end PC with a few graphics cards probably wouldn’t have been much more expensive than several Raspberry Pi’s with cases. However, this system has to just work, and a PC would represent a single point of failure. Even if one Raspberry Pi goes down, the others will continue running.
The current installation is rather messy, but it’s just a test setup. [eN0Rm] has already been taken to task for the lack of cable management in his Reddit thread. As [eNoRm] says – first get it working, then make it pretty.
In the cold and mysterious wilderness of Norway, it pays to be ready for anything–especially heavy-walking trolls. The team at [nullohm] decided to prepare thoroughly for their trek into the woods to witness the Leonids meteor shower by putting together an Arduino-based “troll detector”.
The device is based on the superstition of hammering a steel spike into a tree to keep trolls away from camp. This goes one step further by including an accelerometer and LED indicators so that you can tell exactly what type of troll is just about to feast upon your tender human flesh.
When the detector is installed into a nearby tree, it takes an average seismic measurement and then looks for telltale footfalls. Even if you’re not concerned with perpetuating superstitions, you might find a use for the source code for simple seismic activity monitoring at home to supplement your miniature seismic reflector.