Sometimes we like to take a few minutes away from Hackaday to spend time with our families. But just when you take your eyes off of the incoming comments, Trolls are bound to strike. Well, [Caleb] and I found a solution to the problem in the form of a troll sniffing rat. This beady-eyed vermin sits on my desk and waits. When a trolling comment is detected its eyes glow red and an alarm is sounded. Join us after the break for more about this silly project.
This is an inkjet print head made using a RepRap. The manufacturing process is both simple and ingenious. It uses a vibrating piezo buzzer to pump printing liquid through a tiny nozzle. The red disc seen above is exactly the same diameter as the piezo that resides behind it. There is a hole offset from the center to feed ink in between the two discs. Take a look at the test footage after the break.
To make the nozzle a hole was cut in the plastic disc, then a pin inserted and the whole thing was covered with hot glue. The next step was to remove the pin and shave down the glue until the narrow aperture is open. [Adrian Bowyer] is still in the testing phase for this assembly, but once he gets the bugs worked out he plans to test it with a heating element so that it can print using wax and other materials that are liquid when hot.
[Vik] tipped us off about this one after seeing the printable transistors from the other day.
We know that you can transform the mechanical motions of your body into electrical energy, like when you turn the crank or shake a mechanically-powered flashlight. These types of mechanical motions are quite large compared to many of the day-to-day (and minute-to-minute) actions you perform–for example walking, breathing, and thumb wrestling.
What if we could harvest energy from these tiny movements? Researchers at the Korea Advanced Institute of Science and Technology are seeking the answer to this question with piezoelectric barium titanate. The electrical output of their devices is very small (in the nanoAmps) but over a long period and over many repetitions it would be possible to run a small electric device–even a biologically-embedded one. An alternative to blood power?
There is clearly a lot of potential in this technology, and we’ll be interested to see if and when we can start messing around with this stuff. Heck, it’s already been used to power a small LED and you all know just how much everyone would jump at the chance to cover themselves in self-powered LEDs…
[Emmanuel Roussel] is coding a version of Tetris for the IM-ME. Before you get too excited, he hasn’t actually written the game yet, but instead started with the familiar theme music. The IM-ME has a piezo speak on board so it’s just a question of frequency and duration. [Emmanuel] developed an Open Office spread sheet that calculates each note’s frequency and the timer value needed to produce it. He then created a data type that stores a note and its duration and used an array of those structures to store the song. If you’ve ever wondered how to cleanly code music this is a wonderful example to learn from because right now the code doesn’t have anything other than that code to get in the way.
The ground work for this was established in the other hacks we’ve seen. Now we’re left wondering who will finish coding their game first. Will it be [Emmanuel’s] Tetris or [Travis’] Zombie Gotcha?
Inkjet printheads are a pretty rare thing to see done in home workshops. We would love to see more and got really excited when we saw this single nozzle, drop on demand, head being built. using a piezo disk intended to be a cheap buzzer and some reprap magic, [Johnrpm] got some results. [Madscifi] has been refining the design of the nozzle and the two have shared the process with us. Since it drops a single droplet of liquid, it can be used in a variety of manners, such as dropping plain old boring ink, or dropping a solvent into a powder for some 3d printing. You can see an example of the 3d printing in sugar above.
[via Makezine]
[Wilfred’s] brother outfitted a snare drum with LEDs for Dutch Carnival. They faded through different colors randomly and were a nice addition to the normal looking instrument, but [Wilfred] suggested that the LEDs change color with each drum stroke. He set out to design a controller circuit to provide the functionality and ended with a small package based around an ATtiny2313 microcontroller. A piezo buzzer is used to detect the vibrations inside the drum, each hit triggering a different color combination. The LEDs fade to off after each impact as if dying along with the sound, and when not struck for 30 seconds the system defaults to a red heartbeat pattern. See for yourself after the break.
We’d love to see this feature added to each drum in one of those robotic drumsets. Continue reading “Disco Drumming With Piezo Sensitive Lighting”
We’re being inundated with glove-based peripheral hacks. This is another final project from Cornell, keyboard out of the equation by adding 8 piezo sensors to a pair of gloves thereby shunning the pinky finger. We like this one because it’s easy to build and the midi interface implementation is well documented if you want to build your own.
As you can see after the break, this is easy to use with music software like Garage Band because it is a standard MIDI device. In addition, a MATLAB interface allows for custom mapping in case you want to change what each finger does.
We remember our first introduction to glove-based performances with Tod Machover’s Bug Mudra many years ago. We hope the music input hacks we’re seeing will lead to a whole new generation of music innovators.
