The Formica project was our favorite presentation at 25C3. The goal is to build open source swarm robots as cheaply as possible. The team ended up building 25 robots in an assembly line fashion. With enough lead time, the price could get as low as £15 each. Each bot has two direct drive cellphone vibration motors with tiny neoprene wheels. They’re controlled by an MSP430 microcontroller. The only really specialized chip is a charge controller so the bots can charge without any intervention. They have copper skis on the front that touch the ground plane plus antennas to contact Vcc. On top of the bot are three IR detectors for both navigation and for transferring firmware updates between bots. A reflective sensor is on the underside for detecting “food”. It looks like a great design and any easy way for anyone to start researching swarm robotics.
Breaking from his usually routine of winning at everything, [Glacial Wanderer] has posted one of his projects that didn’t actually work. It’s a Rube Goldberg style card shuffling machine. He wanted something that was visually interesting while still randomizing the cards. A blower would be mounted to the top to mix the cards similar to a lottery ball machine. The cards would then drop into a chute that would make sure all of the cards were oriented correctly before being presented to the user. After building the first prototype, several problems were apparent. The first of which was the fan not being strong enough. His interest was waning and it looked like the time he’d have to invest in fixes was growing quickly, so he decided to cut his loses. He still posted about the prototype in hopes that it could help someone else exploring this sort of machine. A video of the mechanism can be found below.
While we had been excited about 25C3’s CTF competition, we couldn’t even venture a guess as to who would win. It seems the iphone-dev team weren’t satisfied to just give an amazing talk. They teamed up with the Wii hackers from HackMii to win the competition. You can see their progress during the eight hour competition above in red. It’s impressive to see hardware hackers jumping over to network security AND completely killing at it.
[robbtoberfest] put together this cool looking steam powered spud pistol. Made from household materials, like a lighter and some copper pipe, this spud gun builds pressure in its little bitty boiler to expel the projectiles. It seems as though he’s using a cork to supply a seal, so why bother with potatos? At roughly 2 minutes between shots, its not the quickest, but it sure is cool. Good job [robbtoberfest].
[Boris] wanted to help ease his sister’s seasonal affective disorder. The most common way to do it is with fairly expensive light boxes. [Boris] built one of his own instead. Now his sister can blast her sadness away with over 10,000 lumens of CFL happiness. This is pretty much the same method one would use to create a ring light for photography.
Sensirion’s SHTxx is a digitally interfaced humidity and temperature sensor. Accurate humidity measurements usually require careful analog design, but the SHTxx moves all that complicated stuff into a single chip. Through-hole (SHT7x) and surface mount (SHT1x) versions are available, we used the surface mount SHT11 with +/-3% accuracy. We’ll show you how to use the SHTxx below.