Some people like to get high on a Wednesday afternoon. [Kevin Hubbard] of Black Mesa Labs likes to get really high. Even higher than intended: last month, he flew a helium balloon powered by a Raspberry Pi to 103,000 feet. It was only supposed to go to 90,000, but a fault in the code for the controller meant that it went higher, burst and plunged to the ground. All thanks to an extra hash mark in his code.
There have been countless projects to make custom photo flash trigger circuits. Usually the circuits react to sound, triggering the camera flash at the moment a certain sound is triggered. That type of trigger can be used to detect the popping of a balloon or shattering of glass. Other triggers detect motion, like a projectile crossing a laser beam for example. [Udo’s] friend had a fun idea to take photos of water balloons popping. Unfortunately neither of those trigger methods would be well suited for this situation. That’s when [Udo] had to get creative.
[Udo] built a unique trigger circuit that uses the water inside the balloon as the trigger. The core component of the circuit is an Arduino. One of the Arduino’s analog pins is configured to enable the internal pull-up resistor. If nothing else is connected to the pin, the Arduino will read 5 volts there. The pin is connected to a needle on the end of a stick. There is a second needle on the same stick, just a short distance away from the first. When these needles pierce the balloon’s skin, the water inside allows for a brief moment of conductivity between the two pins. The voltage on the analog pin then drops slightly, and the Arduino can detect that the balloon has popped.
[Udo] already had a flash controller circuit. He was able to trigger it with the Arduino by simply trying the flash controller’s trigger pin to one of the Arduino’s pins. If the Arduino pulls the pin to ground, it closes the switch on the flash controller and the flash is triggered. Both circuits must share a common ground in order for this to work.
All of the code for [Udo’s] project is freely available. With such spectacular photographs, it’s only a matter of time before we see more of these floating around.
Looking for a neat decoration for your next soirée? How about floating fleet of glowing balloon blimps?
[Kensho Miyoshi] — an avid reader of Hack a Day — needed an art installation project in Tokyo, he came up with these clever glowing balloon blimps.
They feature a mini gondola hanging from the bottom of a regular balloon which holds a small motor with a propeller, an Arduino Pro Mini, LEDs, an ultrasonic sensor and of course, a battery. They float up to a certain height with the LEDs shining bright, and when the ultrasonic sensor trips, it all turns off and the balloon sinks gently back to the ground. The process repeats, and in a completely dark room it looks like a series of glowing bubbles forming and floating away, again and again.
To see the floaty, glowy, balloon blimps, stick around for a video after the break.
[Will] from Revolt Lab needed a project to get the summer campers he supervises interested in electronics, but when your audience is 5 years old, your subject matter had better be simple, yet interesting enough to hold their attention at length. He settled on using a Lego NXT robot to keep their little minds engaged, because who doesn’t like robots?
He picked up a basic Lego NXT kit and paged through the manual. The first “example” robot looked pretty cool so he decided to give it a shot, though he still hadn’t figured out exactly what he would have the robot do. Inspiration struck, and he decided that he could take advantage of the NXT’s color sensor as well as its proximity sensor to construct a balloon hunting robot.
He constructed a “balloon corral” to keep the balloons in place and the kids out of his thumbtack-wielding robot’s reach. He let his creation loose, and as you can see in the video below, the robot hunts down the blue balloon and pops it, much to the children’s delight.
If you’re in the position to introduce a group of young kids to electronics, this balloon popping robot paired with some conductive Play Dough would make for a fun and educational afternoon workshop.
EL back-lit keyboard
A couple bucks worth of EL wire gives a nice green glow to [Mark Shasha’s] T400 Elite. Hopefully [Jeri Ellsworth] has some time to pull those how-to videos together so that we can make our own EL wire to replicate this hack.
This tiny cannon is right out of Night at the Museum. It works just like its much bigger brothers would; fill with powder, insert cannon ball, and light with a fuse. Both the introduction and the follow-up videos document the destruction of various objects using the diminutive weapon. [Thanks Thorsten]
Don’t close that browser
We use Google Chrome quite a bit because it tends to be more responsive when opening massive numbers of tabs while researching featured hacks. But there’s some things we don’t like about it. Lack of built-in PDF support under Ubuntu comes to mind, but a smaller thorn in our side is that closing the last tab will also close the browser window. [Ted Schaefer] got tired of the same thing so he wrote an extension called Last Tab Standing to trap that last browser tab, opening the default window instead of closing the browser.
Amiga demo winner
Transformers balloon sculptures
If you’re having trouble finding that art piece to fill up your dining room you should consider building transformers out of balloons. The sculpture above is a free-standing Optimus Prime but the artist has also turned out Megatron, Grimlock, and others. [Thanks W01F]