It used to be that when we featured one of [Frank Olson]’s DIY ribbon microphone builds, it was natural to focus on the fact that he was building them almost exclusively from wood. But despite how counterintuitive it may seem, and for as many comments as we get that his microphones shouldn’t work without metal in the ribbon motors, microphones like this wooden RCA Model 77 reproduction both look and sound great.
But ironically, this homage features a critical piece that’s actually not made of wood. The 77’s pickup pattern was cardioid, making for a directional mic that picked up sound best from the front, thanks to an acoustic labyrinth that increased the path length for incoming sound waves. [Frank]’s labyrinth was made from epoxy resin poured into a mold made from heavy paper, creating a cylinder with multiple parallel tunnels. The tops and bottoms of adjacent tunnels were connected together, creating an acoustic path over a meter long. The ribbon motor, as close to a duplicate of the original as possible using wood, sits atop the labyrinth block’s output underneath a wood veneer shell that does its best to imitate the classic pill-shaped windscreen of the original. The video below, which of course was narrated using the mic, shows its construction in detail.
If you want to check out [Frank]’s other wooden microphones, and you should, check out the beautiful Model 44 replica that looks ready for [Sinatra], or the Bk-5-like mics he whipped up for drum kit recording.
Continue reading “Falling Down The Labyrinth With Wooden Microphone Design”
[Daniel], [Gal] and [Maxim] attended a hackathon last weekend – Brainihack 2015 – that focused on neuroscience-themed builds in a day and a half long build off. The trio are communications systems engineering and computer science students with no background in neuroscience whatsoever. You can’t build an FMRI in a day and a half, so they ended up winning the best project in the open source category with a brain-controlled labyrinth game.
The labyrinth itself is entirely 3D printed and much, much simpler than the usual, ‘wooden maze with holes’ that’s generally associated with labyrinth puzzles. It’s really just a plastic spiral for a ball to follow. There’s a reason for this simplicity. The team is using EEG to detect brain waves and move the labyrinth on the X and Y axes.
The team is using OpenBCI for the interface between their brains and a pair of servos. This is actually an interesting piece of tech; unlike a few toys like the NeuroSky MindWave and the Star Wars Force Trainer, the OpenBCI gives you eight input channels that attach to anywhere on the scalp. The team used these inputs to measure Alpha waves and Steady State Visually Evoked Potential to control the pair of servos on the labyrinth frame.
It’s a great build, a wonderful demonstration of a device that outputs real EEG signals, and the team on a prize. What’s not to like?
We’re not sure if this was some type of corporate team building, but if it was sign us up for the next one. [Filipp], [Saluka], and [Michael] participated in a recent 24-hour hackathon hosted by Microsoft. They whipped up this labyrinth game controlled by a Nexus 4 Android phone.
This thing looks so well crafted we’re shocked that it’s a 24-hour build. Just putting together the walls of a maze that size takes some time. They then mounted it in a gimbaled frame which tilts the using servos. Check out the demo video below to get a look at the underpinnings. There are several elastic bands connecting the base to the maze. These act as shock absorbers to help keep the movement smooth and to prevent any oscillations from the frame flexing. For us this is an important design element that we’ll keep in mind (just in case we need to win another competition by designing a labyrinth).
An Arduino controls the servos, using Bluetooth to communicate with the phone. The team mentions some filtering used to help make the user experience more natural but we didn’t see many details on this aspect of the hack.
Continue reading “24-hour Hackathon Produces Respectable Accelerometer Labyrinth”
There’s so much affordable dev hardware out there these days that you can do a lot without even touching a soldering iron. This is a prime example. Texas Instruments software Engineer [Jordan Wills] recently completed this wirelessly controlled marble labyrinth.
Marble mazes like this are a popular targets for electronic tinkering. We’ve seen smartphones used as the controller, and others that dispense chocolate candy. This time around [Jordan] stuck with the store-bought game to simplify the build. A coworker helped by swapping the two control knobs with servo motors. These interface with a Stellaris Launchpad that has a SensorHub booster pack (shield) and CC2533 radio transceiver module. The same hardware makes up the remote unit as well. This turns the remote into an air mouse by reading the gyroscope, accelerometer, and magnetometer from the booster pack.
He doesn’t specifically mention it in his project log, but we think the magnetometer is used to sync orientation between the base unit and the user remote. Even though the board for the base unit is mounted at 90 degrees compared to how you hold the remote, you should still be able to adjust for the readings in code, right?
Continue reading “Wireless Marble Labyrinth Uses TI Dev Hardware”
This entire project could have been done as an app, drawing the maze and ball virtually on the screen. But that wouldn’t have been nearly as fun as what [Matt] accomplished. He built a little Labyrinth which responds to the accelerometer in his phone.
Take a close look at that handset. It’s not an Android, an iPhone, or a Blackberry. That thing is a Windows phone…. no, really! The phone doubles as a timer, which we think is a nice touch. It communicates with a Netduino which is both driving and monitoring the Labyrinth.
You may have noticed that the maze is hand-built rather than a modified commercial version of the toy. He mounted some hardboard on a pair of servo motors, then built up the maze on that surface. There is also sensing hardware that detects when the metal ball bridges two contacts. This gives us fond memories of our Minotaur’s Revenge build.
We’ve embedded the demo video after the break.
Continue reading “Smartphone Controlled Labyrinth”
Go Vote Now! update: looks like the vote button opens a popup to a Facebook app. this is required to vote :(
For the full writeup on our entry, go here!
Continue reading “Voting Is Open For The Red Bull Creation Contest. Go Team Hackaday!”
[Pcdevltd] pulled an all-nighter to get his first Android Developer Kit project up and running. Basing the project off of the example that Google used when unveiling the new accessory development hardware, he set to work controlling a marble labyrinth game using his smart phone. What began at 7pm was wrapped up by 5am to produce the results seen in the video after the break.
These ball mazes use two knobs to pivot the playing surface, changing gravity’s pull on the ball to get it to go where you want. [Pcdevltd] pulled off the bottom on his labyrinth and installed two small servo motors. These connect to the Android Open Accessory Development Kit via a small cable. Connect that to the phone and you can then use the internal accelerometer to play the game. If you have an Android phone and an Arduino this should be pretty easy to replicate since we know you can already use the ADK with Arduino. Get to work on your own projects and don’t forget to send us a link to your project log.
Continue reading “Android Controlled Labyrinth”