[Mats] is hacking on his PlingPlong synthesizer. The first Easter egg—which you can see in the clip after the break—launches with the H-A-D chord in the lower octave, spelling out our URL on the 7-segment displays. But we prefer the second egg, launched with the chord in the upper octave, which is shown above. It uses the 3×5 LED grid to scroll out the address; in this still image an H is displayed.
[Jason] just tipped us off about his recent experiment, in which he creates a sonar system using standard audio equipment and a custom Python program. In case some of our readers don’t already know it, Sonar is a technique that uses sound propagation to detect objects on or under the surface of the water. It is commonly used in submarines and boats for navigation. [Jason]’s project uses active sonar, which consists in sending short audio bursts (chirps) and listening for echoes. The longer it takes for the echo to return, the further the object is. Though his proof of concept is not used underwater, that may change if he continues the project.
The audio editing software Audacity was used to make a fast frequency changing chirp, along with PyAudio libraries for the main Python program. Exact time of arrival is detected by correlating the microphone output with the transmitted signal. Given that [Jason] uses audible frequencies, we think that the final result shown in the video embedded below is quite nice. Continue reading “Sonar With Python And Conference Call Hardware”→
Here’s a round-up of three different Fubarino Contest entries; a video of each is available after the break.
On the upper left are the beginnings of a network node monitoring system developed by [Stephane]. When the network checks the weather, it may determine that it’s far too harsh outside and time to go in to see what’s new on Hackaday. There’s only sparse information available on the hardware. Each node uses an ATtiny84 and an RFM12B—different sensors connected to each are used to build up the network’s data collection capabilities.
In the lower left is [Brett’s] Bluetooth door lock controller. The Arduino, a cheap Bluetooth module, and a relay board make up the base station which will eventually connect to an electronic lock. [Brett] uses a smart phone to punch in the access code, and entering “1337” four times in a row unlocks the Easter egg, displaying our URL on the character LCD. Here’s the code repository for his project.
At the end of every semester, we get a bunch of cool and well-documented student projects from Cornell’s ECE4760 class. [Scott] and [Alex]’s infrared theremin is no exception.
The classic theremin design employs each of the player’s hands as the grounded plate of a variable capacitor in an LC circuit. For the pitch antenna, this circuit is part of the oscillator. For the volume antenna, the hand capacitor detunes another oscillator, changing the attenuation in the amplifier.
[Scott] and [Alex] put a twist on the theremin by using two IR sensors to control volume and pitch. The sensors compute the location of each hand and output a voltage inversely proportional to its distance from the hand. An ATMega1284P converts the signal to an 8-bit binary number for processing. They built four voices into it that are accessible through the push-button switch. The different voices are created with wave combinations and modulation effects. In addition to Classic Theremin, you can play in pure sine, sawtooth, and FM modulation.
Excellent results can come from a small CNC router, but don’t forget the software!
CNC tools, whatever their flavor, can greatly enhance your “making” or DIY ability. My current tool of choice is a CNC router. Being familiar with a manual milling machine, the concept seemed similar, and the price of these is quite reasonable when compared to some other tools. As described in this post, my machine is a Zen Toolworks model, but there are certainly other options to visit like this Probotix V90 model noted recently in this post.
Although any number of CNC router models look great in videos and pictures, rest assured that even the best machines require some patience to get one running satisfactorily. Setting up the machine can be a challenge, as well as figuring out what your machine is capable of, but one thing that might slip peoples’ minds is the software involved. Read on to find out all you need to know the basics of what goes on behind the scenes to “magically” produce interesting parts. Continue reading “Software Advice For Anyone Thinking About A CNC Router”→
[Ferdinand] sent in a tip about the very cool DelFly Explorer, built by researchers at Netherlands’ Delft University of Technology, which is claimed to be the world’s first autonomous, flapping micro air vehicle. While it doesn’t fly like a typical ornithopter, the specs will convince you not to care. It has an 28 cm wingspan and weighs 20 grams, which includes motors, a battery, two cameras, and an autopilot. The autopilot uses accelerometers and a gyroscope, plus a barometer for altitude measurement. You can see the on-board video at the 35-second mark on the video (after the break). They are incredibly noisy images, but apparently the researchers have come up with some algorithms that can make sense of it.
Put it all together, and you have a machine that can take off, maintain altitude, avoid obstacles, and fly for nine minutes. We’ve seen a cool ornithopter design before, and even a thrust vectoring plane, but this surpasses both projects. It’s pretty incredible what they have been able to fit into such a small design.
[Unixgeek] owns an Optrel welding hood, which contains a lens that auto-adjusts for various welding tasks. It stopped working properly, and this hood is “Non-Serviceable”, so he had to either throw it away or hack it. The problem was that he knew it contained batteries, but they weren’t accessible. Using his milling machine, he was able to fix it himself. After removing the outer layer of plastic [Unixgeek] found that it was filled with foam. With continued milling he finally uncovered the batteries. They are standard CR2330 cells, so he could easily replace them, or set up a separate battery holder.