Monday, March 31, 2014 - 07:00From the Forums – Adafruit Trellis Geome Midi Sequencer #trellis #genome #midi
Midi music eight step sequencer demo for Adafruit Trellis keypad. Driven by Arduino Uno. Button data sent to Midi Shield. Midi data sent to Yamaha Midi sound module.
Top six rows used for entering note data. Up to 6 notes (pentatonic scale) per step. Bottom row enables random octave shifting for given step. Second row buttons enable echo from three notes back from current step.
Here is the code for the Geome sequencer.
This works pretty well. Not too glitchy. Would really like to be able to handle Trellis within an interrupt handler. That way it would be easier to implement midi clock signal, etc., as I am doing with some other projects.
Featured Adafruit Product!
Adafruit Trellis Monochrome Driver PCB for 4×4 Keypad & 3mm LEDs: This item is just for the Trellis driver PCB assembly: LEDs and buttons not included. Trellis is an open source backlight keypad driver system. It is easy to use, works with any 3mm LEDs and eight tiles can be tiled together on a shared I2C bus. This PCB is specially made to match the Adafruit 4×4 elastomer keypad. Each Trellis PCB has 4×4 pads and 4×4 matching spots for 3mm LEDs. The circuitry on-board handles the background key-presses and LED lighting for the 4×4 tile. However, it does not have any microcontroller or other ‘brains’ – an Arduino (or similar microcontroller) is required to control the Trellis to read the keypress data and let it know when to light up LEDs as desired. Each tile has an I2C-controlled LED sequencer and keypad reader already on it. The chip can control all 16 LEDs individually, turning them on or off. It cannot do grayscale or dimming. The same chip also reads any keypresses made with the rubber keypad. The connections are ‘diode multiplexed’ so you do not have to worry about “ghosting” when pressing multiple keys, each key is uniquely addressed. (read more)
Monday, March 31, 2014 - 07:00Using a Door Handle Conductivity to Detect Intruders
Sometimes the simplest projects can be quite interesting, provided they’re well documented. We hope that the Hackaday readers also think that the door sensor that [Alexander] developed falls into this category. Instead of using common methods such as a magnet + reed switch, he decided to use the strike plate and door conductivity to detect someone walking in. The setup he put together includes an Arduino, a PowerSwitch Tail (a power cord that switches 120vac with a dc control voltage of 3-12vdc), a battery pack made of 8 AA batteries and two crocodile clips for door connections.
Most new hobbyists would have stopped there, but [Alexander] checked his platform’s power consumption and continued his work to decrease it. He therefore put the microcontroller in power-down mode by default and uses an AVR external interrupt to wake it up. In case beginners can’t understand [Alexander]‘s code, he actually put a nice flow diagram on his website. Embedded after the break is a video of the system working.
Filed under: Arduino Hacks
Monday, March 31, 2014 - 06:00IRL Version of circle stop using Adafruit Neopixel ring!
A team here at @pearlhacks built a real version of #circlestop!
Featured Adafruit Product!
NeoPixel Ring – 12 x WS2812 5050 RGB LED with Integrated Drivers: Round and round and round they go! 12 ultra bright smart LED NeoPixels are arranged in a circle with 1.5″ (37mm) outer diameter. The rings are ‘chainable’ – connect the output pin of one to the input pin of another. Use only one microcontroller pin to control as many as you can chain together! Each LED is addressable as the driver chip is inside the LED. Each one has ~18mA constant current drive so the color will be very consistent even if the voltage varies, and no external choke resistors are required making the design slim. Power the whole thing with 5VDC and you’re ready to rock. Read more.
Monday, March 31, 2014 - 04:00Controlling The Garmin HUD With Bluetooth
The Garmin HUD is a very neat device, putting all your navigational info, from ETA, what lane you should be in, and distance to your next turn right on your windscreen in a heads-up display. The only problem with the Garmin HUD is that it only works with the official Garmin app, despite being a Bluetooth device. Now, someone is finally digging in to the Garmin HUD protocol, allowing anyone to control this HUD from a cell phone, tablet, or computer.
Being completely unable to disassemble the Navigon app for the HUD, [gabonator] decided the only thing to do would be to open up the device and take a peek at some of the packets travelling between the microcontroller and bluetooth module.
[gabonator] expected human readable ASCII characters, but after looking at the nonsense decoded from his oscilloscope and decoding them manually, he tried simply looking at the display in operation to understand how the protocol worked. He got it all decoded, and managed to get a Sygic Navigation program working with this Garmin HUD. You can check out a video of that below.
Thanks [Kevin] for the tip.
Filed under: transportation hacks
Monday, March 31, 2014 - 01:01Hackaday Links: March 31, 2014
Wanting to display his Google calendars [Chris Champion] decided to mount an old monitor on the wall. The hack is his installation method which recesses both the bracket and the outlet while still following electrical code (we think).
Since we’re already on the topic. Here’s a hack-tacular project which hangs a laptop LCD as if it were a picture frame. We do really enjoy seeing the wire, which connects to the top corners and hangs from a single hook a few inches above the screen bezel. There’s something very “whatever works” about it that pleases us.
[Jaspreet] build a datalogger in an FPGA. He put together a short video demo of the project but you can find a bit more info from his repo. He’s using a DE0-Nano board which is a relatively low-cost dev board from Terasic.
Want to see what’s under the hood in the processor running a Nintendo 3DS? Who wouldn’t? [Markus] didn’t just post the die images taken through his microscope. He documented the entire disassembly and decapping process. Maybe we should have given this one its own feature?
If you’re streaming on your Ouya you definitely want a clean WiFi signal. [Michael Thompson] managed to improve his reception by adding an external antenna.
We always like to hear about the free exchange of information, especially when it comes to high-quality educational material. [Capt Todd Branchflower] teaches at the United States Air Force Academy. He wrote in to say that his ECE383 Embedded Systems II class is now available online. All the info can also be found at his Github repo.
And finally, do you remember all the noise that was made about 3D printed guns a while back? Well [Mikeasaurus] put together the .iStab. It’s a 3D printed iPhone case with an integrated folding blade…. for personal protection? Who knows. We think it should be a multitasking solution that functions as a fold-down antenna.
Sunday, March 30, 2014 - 23:23HARDWARE HANGOUT with Brady Forrest Tuesday 7pm ET 4/1/14 #makerbusiness @brady @highway1io @PCH_Intl #Hardware #startup #incubator
Come meet and ask questions on our next HARDWARE HANGOUT with Brady Forrest. Brady runs Highway1 and helps shepherd startups of all backgrounds into their Accelerator program. He also co-founded Ignite – a geek event which has spread to over a hundred cities worldwide.. PCH is a large supply chain management company with primary operations in Shenzhen. It ships $10B of product annually. Highway1 helps you get your prototype ready for market. Based in SF, they are a four month program & currently hosting 11 companies – primarily consumer. The next class runs Mar-Jun. More about Brady – he is Vice President at Highway1, PCH International’s incubator program. A prolific speaker and maker on the geek scene, Brady can be found at speaking engagements around the world, inventing new forms of transportation at Burning Man, or creating in the Highway1 San Francisco workshop. Additionally, Brady writes for O’Reilly Radar, tracking changes in technology.
Things we’ll be asking!
- When/if makers should crowdfund?
- When do you hire certain roles?
- What are the hidden gotchas?
- When/should you go to China?
- The role of opensource
Post your questions here, on G+, join live and more!. Click here for the Google+ Hangout page (you can start asking your questions now too).
Sunday, March 30, 2014 - 22:00Measuring Magnetic Fields with a Robotic Arm
Learning how magnets and magnetic fields work is one thing, but actually being able to measure and see a magnetic field is another thing entirely! [Stanley's] latest project uses a magnetometer attached to a robotic arm with 3 degrees of freedom to measure magnetic fields.
Using servos and aluminium mounting hardware purchased from eBay, [Stanley] build a simple robot arm. He then hooked an HMC5883L magnetometer to the robotic arm. [Stanley] used an Atmega32u4 and the LUFA USB library to interface with this sensor since it has a high data rate. For those of you unfamiliar with LUFA, it is a Lightweight USB Framework for AVRs (formerly known as MyUSB). The results were plotted in MATLAB (Octave is free MATLAB alternative), a very powerful mathematical based scripting language. The plots almost perfectly match the field patterns learned in introductory classes on magnetism. Be sure to watching the robot arm take the measurements in the video after the break, it is very cool!
[Stanley] has graciously provided both the AVR code and the MATLAB script for his project at the end of his write-up. It would be very cool to see what other sensors could be used in this fashion! What other natural phenomena would be interesting to map in three dimensions?
Filed under: robots hacks
Sunday, March 30, 2014 - 21:29New Project: Controlling a lock with an Arudino and Bluetooth LE
Sunday, March 30, 2014 - 21:29New Project: Controlling a lock with an Arduino and Bluetooth LE
Sunday, March 30, 2014 - 19:00Reflowing With A Hair Straightener
Around here, reflow ovens usually mean a toaster oven, and if you’re exceptionally cool, a thermistor and PID controller. There are, of course, a thousand ways to turn solder paste into a solid connection and [Saar] might have found the cheapest way yet: a hair straightener with a street value of just £15.
We don’t expect the majority of the Hackaday demographic to know much about hair straighteners, but [Saar] has done all the work and came up with a list of what makes a good one. Floating plates are a must to keep the PCB in contact with the heating element at all times, and temperature control is essential. [Saar] ended up with a Remington S3500 Ceramic Straight 230 Hair Straightener, although a trip to any big box store should yield a straightener that would work just as well.
One modification [Saar] added was a strip of Kapton tape to one of the ceramic heating elements. It’s not a replacement for a toaster oven or real reflow oven, but for small boards it works just as well.
Filed under: tool hacks
Sunday, March 30, 2014 - 17:22Brighten Your Smile with Weekend Projects and the Toothy Toothbrush Timer
Sunday, March 30, 2014 - 16:00LEGO® My Single-Phase Induction Motor
[Diato556] made a really cool single-phase induction motor with parts mounted on Duplo blocks. He has posted an Instructable where he uses these modular parts to demonstrate the motor and the principles of induction as described after the jump.
[Diato556] starts with an AC generator, a tiny alternator made with the coil from a relay and the magnet from a bicycle dynamo. He rotates the magnet on a spit in front of the relay coil, producing an induced current that lights an LED connected to the relay.
Rotating magnetic field
Next up is a rotating magnetic field demonstration. Using the same rotisserie magnet, he induces a current in a rotor made from a small aluminium cylinder. The cylinder pivots against a nail and induced current causes the rotor to spin.
The induction motor builds from previous experiment. Instead of the magnet, the two coils induce current in the rotor. One is fed directly from 12VAC, and the other coil’s power is delayed with a 4.7μF capacitor. The alternating magnetic field causes the rotor to spin.
This is a neat project on so many levels. The modular Duplo-entrenched parts are just plain cool. Give demonstrations at the office, or just keep it around as a fun desk toy or conversation piece. If you don’t have a desk and must carry your conversation pieces on your person, you can’t go wrong with this induction flashlight.
Sunday, March 30, 2014 - 13:00DIY Bluetooth Boombox Can Take a Beating!
Looking for a nice portable audio solution that can take a beating outdoors? This RaveBOX (v1.0) might be what you’re looking for!
[Angelo] is a 15 year old high school student from the Philippines who loves making things — in fact, he has a collection over 40 Instructables that he’s written himself to share with the world. He wrote his first when he was only 10 years old.
He was inspired to build this boombox when he stumbled upon a Pelican-like rugged case at the mall, so he bought it and started planning the build around it. He’s using a pair of 2-channel audio amplifiers hooked up to a Bluetooth/FM/USB/SD card player module which has a nice face-plate for external mounting. It drives a 4″ woofer, and 4 full range speakers. To modify the case, he used a Dremel and pocket knife, and we must say, he did a great job! The 12V 2.2aH lithium polymer battery provides a surprising 18 hours of playback.
It’s a great beginner’s project to get into soldering — nothing too complex, but the resulting boombox is quite useful — and [Angelo's] got a great guide to get you started!
If you’re looking for a bit more stylish boombox, why not build one out of a briefcase?
Filed under: digital audio hacks
Sunday, March 30, 2014 - 10:00Malware In A Mouse
Keyloggers, in both hardware and software forms, have been around for a long, long time. More devious keyloggers are smart enough to ‘type’ commands into a computer and install Trojans, back doors, and other really nasty stuff. What about mice, though? Surely there’s no way the humble USB mouse could become an avenue of attack for some crazy security shenanigans, right?
As it turns out, yes, breaking into a computer with nothing but a USB mouse is possible. The folks over at CT Magazine, the preeminent German computer rag, have made the Trojan mouse (German, terrible Google translation)
The only input a mouse receives are button presses, scroll wheel ticks, and the view from a tiny, crappy camera embedded in the base. The build reads this camera with an Arduino, and when a certain pattern of gray and grayer pixels appear, it triggers a command to download a file from the Internet. From there, and from a security standpoint, Bob’s your uncle.
Looking through the camera inside a mouse is nothing new; it’s been done over the Internet and turned into the worst scanner ever made. Still, being able to process that image data and do something with it is very cool. Just don’t accept mouse pads from strangers.
Danke [Ianmcmill] for the tip.
Sunday, March 30, 2014 - 09:0014-year-old can save the government millions by changing font style
14-year-old Suvir Mirchandani’s science fair project was to determine how his middle school could reduce ink usage to cut waste and cost. What he found would save his school thousands of dollars, and, if applied to the federal and state governments, millions!
“Ink is two times more expensive than French perfume by volume,” Suvir says with a chuckle.
He’s right: Chanel No. 5 perfume costs $38 per ounce, while the equivalent amount of Hewlett-Packard printer ink can cost up to $75.
So Suvir decided to focus his project on finding ways to cut down on the costly liquid.
Collecting random samples of teachers’ handouts, Suvir concentrated on the most commonly used characters (e, t, a, o and r).
First, he charted how often each character was used in four different typefaces: Garamond, Times New Roman, Century Gothic and Comic Sans. Then he measured how much ink was used for each letter, using a commercial tool called APFill® Ink Coverage Software.
Next he enlarged the letters, printed them and cut them out on cardstock paper to weigh them to verify his findings. He did three trials for each letter, graphing the ink usage for each font.
From this analysis, Suvir figured out that by using Garamond with its thinner strokes, his school district could reduce its ink consumption by 24%, and in turn save as much as $21,000 annually.
With encouragement from his teacher and the founders of the Journal for Emerging Investigaors, Suvir applied his research to a larger institution, the government.
Using the General Services Administration’s estimated annual cost of ink — $467 million — Suvir concluded that if the federal government used Garamond exclusively it could save nearly 30% — or $136 million per year. An additional $234 million could be saved annually if state governments also jumped on board, he reported.
Sunday, March 30, 2014 - 08:00Using Minecraft to Understand the Speed of Light
Sunday, March 30, 2014 - 07:00Scientists Create Biodegradable Battery That ‘Melts’ Inside The Body After Use
An exciting new biodegradable battery unveiled by a team of scientists could have huge potential for biomedical devices. The tiny battery can be safely absorbed by the body within just three weeks and could be used in temporary devices intended to monitor tissue or deliver short term treatment. From Nature:
Their devices, described last week in Advanced Materials, use anodes of magnesium foil and cathodes of iron, molybdenum or tungsten. All these metals will slowly dissolve in the body, and their ions are biocompatible in low concentrations. The electrolyte between the two electrodes is a phosphate-buffered saline solution, and the whole system is packed up in a biodegradable polymer known as a polyanhydride.
Currents and voltages vary depending on the metal used in the cathode. A one-square-centimetre cell with a 50-micrometre-thick magnesium anode and an 8-micrometre-thick molybdenum cathode produces a steady 2.4 milliamps of current, for example. Once dissolved, the battery releases less than 9 milligrams of magnesium — roughly twice as much as a magnesium coronary artery stent that has been successfully tested in clinical trials, and a concentration that is unlikely to cause problems in the body, says Rogers. “Almost all of the key building blocks are now available” to produce self-powered, biodegradable implants, he says.
All versions can maintain a steady output for more than a day, but not much longer. The team hopes to improve the batteries’ power per unit weight — known as power density — by patterning the surface of the magnesium foil to increase its surface area, which should enhance its reactivity. The authors estimate that a battery measuring 0.25 cm2 and just one micrometre thick could realistically power a wireless implantable sensor for a day.
Sunday, March 30, 2014 - 07:003D Printed Instrument Roundup
We just stumbled upon a great repository of all musical things that are 3D printed. It’s a wiki dedicated to sharing and recording these 3D printed instruments to help encourage further ideas and projects.
The people maintaining the site find different projects and share them, adding descriptions which would go great into a database search. They explain the type of instrument, it’s history, a picture or video of it and the method of manufacture used to create, whether it be traditional 3D printing, laser cutting, or another process.
Some of our favorites include the 3D printed guitar bodies, the strange looking multi-horn trumpet (that’s the weird one, bottom right) by the MIT Media Lab, and of course the humongous bass recorder (top right).
Stick around after the break for a few videos of these
differentunconventional, unorthodox instruments!
Or this ridiculously cool minimalist 3D printed guitar…
Sunday, March 30, 2014 - 06:00Take a Look at the First Successfully Transplanted, 3D-Printed Skull
Big news in 3D printing and medical implants this week! Doctors have declared the first 3D printed skull replacement surgery they performed 3 months ago to be a success. From io9:
The surgery was performed in the University Medical Center at Utrecht University, after surgeons there began treating a patient with a condition that was causing a thickening of the skull to almost 3 times its normal thickness, putting pressure on the brain.
By replacing her skull with a 3D printed one — a process that took over 23 hours of surgery — they were able to alleviate that pressure and, three months after the surgery, the doctors report that the patient has already gone back to work.
Sunday, March 30, 2014 - 06:00An Engineer’s Eureka Moment With a G.M. Flaw
Somewhere inside the two-inch ignition switch from the 2005 Chevrolet Cobalt was the clue that Mark Hood was seeking.
Mr. Hood, an engineer in Florida, had photographed, X-rayed and disassembled the device in the fall of 2012, focusing on the tiny plastic and metal switch that controlled the ignition. But even after hours of testing, Mr. Hood was at a loss to explain why the engine in Brooke Melton’s Cobalt had suddenly shut off, causing her fatal accident in 2010 in Georgia.
It was no small matter to her family, which had hired Mr. Hood for their lawsuit against General Motors.
Then he bought a replacement for $30 from a local G.M. dealership, and the mystery quickly unraveled. For the first time, someone outside G.M., even by the company’s own account, had figured out a problem that it had known about for a decade, and is now linked to 13 deaths.
The discovery was at once subtle and significant: Even though the new switch had the same identification number — 10392423 — Mr. Hood found big differences. A tiny metal plunger in the switch was longer in the replacement part. And the switch’s spring was more compressed. And most important, the force needed to turn the ignition on and off was greater.