Tuesday, February 25, 2014 - 19:00Retrotechtacular: Hacking Mother Nature’s North Temperate Regions
…because they’ll tickle your insides! Seriously, don’t eat them if you happen to parachute alone into wilderness and must survive without firearms or equipment like our protagonist here. This 1955 US Navy-produced gem of a training film will show you how to recognize, procure, and prepare many kinds of nutritious plant, insect, and animal life commonly found between 45° and 70° north latitude.
While you hone your large game hunting skills, you can tide yourself over with all kinds of things that will just sit there ready to be plucked for your nourishment: many berries and fruits, nuts, moss, lichens, and the inner bark of several kinds of trees is edible. Sate your taste for savory with grubs, termites, or grasshoppers. When in doubt, eat what the birds and small animals are eating, but stay away from mushrooms. It’s too hard to distinguish the poisonous varieties.
Many edible things are found in and around bodies of water. Game such as deer, ducks, and birds are attracted to water and make their homes near it. Various kinds of traps made from twigs and vegetation will outwit rabbits and squirrels. You can fashion a bow and arrow in order to kill large quadrupeds like deer, elk, and ram. It’s best to aim for the head, neck, or just behind the shoulders as these are the most vulnerable areas.
Once you have killed a large animal, prepare it for cooking by draining its blood and removing its entrails. There are many ways to cook your spoils of survival, and most of them involve cutting the meat into small pieces first. Hopefully, you have some basic tools for starting fires.
Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.
Tuesday, February 25, 2014 - 16:00US Government Screws Up Terrorist Watchlist, Few Surprised
It looks like [Dave Jones] got himself on a US government watch list. We don’t mean [Dave L. Jones], awesomesauce electronic wizard and host of eevblog, though. Some three-letter agency is just looking at someone named [David Jones]. Is this going to screw over our Aussie friend? You betcha.
[Dave] bought a few things through Element 14 that he would later pick up at their Sydney warehouse. When he got there, he discovered the parts were ‘on hold’. Out of curiosity, he asked what the holdup was and discovered his name was flagged on a US government watch list.
If you’re keeping score, this is an Australian citizen buying stuff from an Australian subsidiary of a UK company, and being told ‘no’ by the US government.
The folks behind the counter at the Element 14 warehouse were extremely helpful, clearing the hold and getting [Dave]‘s parts in just a few minutes. This has, apparently, been going on for a while; [Dave] recalled a few times when orders showed up a few days late with the Farnell/Element 14 people apologizing with the word ‘hold’ in there somewhere.
Of course this means it’s possible for someone working at the Element 14 warehouse to clear one of these US government holds, and even if they don’t the order will still go through in a day or two. Government efficiency at its best.
At the time of this writing, [David Bowie], the singer for The Monkees, the creator of Grand Theft Auto, and the British author famous for perpetual motion machines were unavailable for comment. -ed.
Filed under: news
Tuesday, February 25, 2014 - 13:00This Little Piggy Stayed Home and Became a Stove
This little piggy probably should have gone to the market. Instead, its become an extremely decorative, and cute, wood burning stove!
After being inspired by a similar Instructable that guides you through the creation of a wood stove using an expired gas cylinder, [Ruudvande] had to try it himself. The problem was — he didn’t have a gas tank. Luckily for him, he found someone who did, but as it turned out, they wanted to turn it into a barbecue! So, slightly sidetracked, he built them a barbecue using the center of the cylinder, and got to keep the ends and enough steel to make Mr. Piggy himself.
Almost the entire wood burning stove is made of scrap bits and pieces of steel, and various pieces of mounting hardware. Armed with just a MIG welder, [Ruudvande] welded it together all by hand, and we think it turned out great! He’s not quite happy with it yet though and plans to upgrade the chimney, put a larger grill inside, paint it, and even add a glass window to the door.
Filed under: cooking hacks
Tuesday, February 25, 2014 - 10:00NXP’s ARM Micros With Motor Controllers
It’s still relitavely early in the year, and all those silicon manufacturers are coming out with new toys to satiate the engineer and hobbyist for years to come. NXP’s offering is the LPC1500, a series of ARM microcontrollers optimized for motor and motion-control applications.
The specs for the new chips include an ARM Cortex-M3 running at 72MHz, up to 256kB Flash, 36kB SRAM, USB, CAN, 28 PWM outputs, an a real-time clock. There are options for controlling brushless, permanent magnet, or AC induction motors on the LPC1500, with dev boards for each type of motor. Each chip has support for two Despite NXP’s amazing commitment to DIP-packaged ARM chips, the LPC1500 chips are only available in QFP packages with 48, 64, and 100 pins.
Don’t think the LPC1500 would be a perfect chip for a CNC controller – the chips only support control of two motors. However, this would be a fantastic platform for building a few robots, an electric car, or a lot of the other really cool projects we see around here.
Tuesday, February 25, 2014 - 07:01Cyclone Dust Collector Requires No Bags or Filters
After discovering their dust collection vacuum was blowing through filters and leaking powdered fiberglass dust all over their workshop, the folks at i3Detroit decided to take matters into their own hands, and built this awesome cyclone dust collector that requires no bags or filters!
They were inspired by a similar wooden sawdust collector, but as they cut many different materials, they decided to build a steel cyclone for durability. The build makes use of two 5-gallon buckets, a 5-gallon vacuum cleaner, and a meticulously designed sheet metal cyclone cone. The vacuum creates a strong suction force and the dust enters the cyclone, getting sucked to the bottom and into the blue bucket. This keeps the filter in the vacuum clean, and keeps all the debris in an easy to access bucket.
To build the cone they used galvanized sheet metal, and cut it to shape with a pneumatic nibbler. A sheet metal roller helped form the cone, which was then riveted together. To seal in the cracks they used duct sealer and foil tape. After adding some vacuum hose and accessories the build was done — approximate cost (minus the shop vac) was around $50, making it a very affordable and quick to pay off project considering the cost savings of replacement bags and filters.
To see another example of cyclone styled dust collectors, check out this one which can also be made using stuff you probably have lying around the shop anyway!
Filed under: cnc hacks
Tuesday, February 25, 2014 - 04:01EL Wire Nixie Tube is in your Reach
Nixie tubes are awesome, but sometimes a little out of reach for some makers, whether it is a matter of obtaining them, or figuring out how to drive them. The hackerspace over at H3 Laboratories decided to try making a fun alternative — EL wire nixie tubes.
[Marty] leads us through the build in a very detailed Instructable, which makes use of CoolNeon EL wire. He’s using an Arduino Uno with a CoolNeon shield to control it. The trickiest part of this build is forming the numbers to minimize the overlap — to figure this out he modeled it in Blender. He created a test jig and formed the numbers using coat hanger wire first before playing around with the EL wire.
EL wire can be soldered together — it’s just a bit of a fine art, which is explained in another detailed Instructable. To black out parts of the number and the trailing wires, [Marty] made use of black plastic dip. The numbers are mounted on a Styrofoam cylinder which fits into the bottom of a large masonry jar. It’s a great build and a fun project to get into Nixies … without actually getting into Nixies.
Stick around for a video of it in operation.
Filed under: Arduino Hacks
Tuesday, February 25, 2014 - 01:013D Printing Metal Structures with a 6-axis Robot
[Joris Laarman] is working on a project called the MX3D-Metal which uses an ABB industrial robot arm and a welding machine to create strong metal structures on any working surface and in any direction.
He started last year with the MX3D Resin printer, which is the exact same concept, but instead of metal, it uses a two-part epoxy that bonds instantly upon mixing. Their lab is located in Amsterdam, and they work closely with IAAC (the Institute for Advanced Architecture of Catalonia) — Autodesk provides funding for the research.
[Joris] has successfully printed complex structures using steel, stainless steel, bronze, copper, and even aluminum. Poking around their website you can find many examples of different things they have printed, including intricate matrices of multiple curved lines which end up looking more organic than mechanical. It uses mostly the same concept as the Rostock Welding robot we covered a few months ago, which is open source and fairly cheap to make at home!
Stick around for a video of both the MX3D-Metal and Resin robot printers in action!
Monday, February 24, 2014 - 22:01We Salute the Television Tube Flag
From [Gijs] comes Beeldbuis Vlag Tijsdlijn, or television tube flag (Translated). We’re not up on our Dutch, but it appears that [Gijs] and friends have created a television tube which waves much like a flag in response to airflow from a fan. The effect is pretty darn amazing, and that’s putting it mildly. To create this hack, [Gijs] built a modified Wobbulator. The Wobbulator is an early video synthesizer which used added steering coils to modify the operation of a standard TV tube. When excited, the coils would deflect the tube’s electron beam, causing some rather trippy images to appear on-screen. (Yes, here at Hackaday “trippy” is a scientific term).
[Gijs] wanted his screen to be “waved” by a fan, just like a flag would wave. To do this he used an anemometer made of ping-pong ball halves. The anemometer spins up a DC motor from a CD-ROM drive. In this application, the motor acts as a generator, creating a DC voltage. An ATmega328 running the Arduino code reads the voltage from the motor. If the anemometer is spinning, the Arduino then outputs a sinusoidal value. The Arduino’s output is amplified and applied to the coil on the CRT. A network of power resistors ensures the amplifier is correctly loaded. The results speak for themselves. In the video after the break, the tube flag is displaying a slide show of photographs of its construction. As an added hack, [Gijs] used an Arduino Leonardo as a USB keyboard. When the anemometer spins, the primary ATmega328 sends a signal to the Leonardo, which then emulates a push of the arrow keys on the host computer. This lets the tube flag advance its own images. Very cool work indeed!
Filed under: video hacks
Monday, February 24, 2014 - 19:01Guest Post: Try Radar for Your Next Project
Sensors. The low-end stuff that we can get our hands on usually suffers from poor range, lack of sensitivity, and no way to characterize what the target is. But today we can use the good stuff that, until recently, was only available to military: radar. In this post we will discuss how radar works, commercially available small radar devices, and where to learn more to help make it easy to add radar to your next project. Reach out and sense something!
Radar is simple, it consists of a radio transmitter and receiver. Radar is a World War Two acronym meaning Radio Direction and Ranging, in other words a radar consists of a radio transmitter and receiver where the range to an object is measured by clocking the time between the transmitter transmitting a known modulated waveform and the receiver receiving this waveform scattered from a target.
One enabling technology for Radar was the cathode ray tube (CRT), which facilitated a method of measuring the time delay between transmitted and received waveforms. This led to the development of numerous radar sensors used in the second world war, which generally followed the Plan Position Indicator (PPI) architecture.
Toady, rather than using a CRT we can use high-speed digitizers. This offers the obvious advantage of applying signal processing to acquired data so that only moving targets are detected, tracking can be achieved, imaging, and a multitude of other modes.
But for hobbyist and consumer projects we do not need this much power, range, and can not afford the cost. We need the ability to sense like a long range radar (detecting only moving targets, imaging, Doppler, signatures, etc) but at short ranges and at low costs.
Very few off-shelf small radar options exist as of today. In this post we’ll review these, their basic architectures, and direct you on the next steps.
Continuous Wave (CW) Doppler Radar
If you are not interested in ranging or imaging but would like to measure velocities or radar signatures then consider CW Doppler radar. CW Doppler radar works by feeding the output of a CW oscillator to an antenna and radiates that carrier towards a moving target. This carrier scatters off the moving target back to the receive antenna where it is amplified and fed to a frequency mixer. The mixer mixes the oscillator and the scattered carrier resulting in a Doppler shift product. This product is the Doppler shift off of the carrier’s center frequency and is generally in the KHz range. Low enough to be easily digitized by the audio input port of a laptop computer or other low-cost digitizer.
Try a CW Doppler radar. You can hack an old police radar gun by locating the video amplifier or mixer’s output and plugging that signal into the audio input port of your laptop and displaying this data using a ‘water fall’ Fourier transform.
If you find an old motion sensor or door opener. These typically use CW Doppler radar modules known as Gunnplexers. Hack into one just as you would with the Police radar.
Or, you can procure new off-shelf X-band CW Doppler radar devices from China for < $10 on Ebay. I’ve used these devices before, they do work but have limited range. This may not matter for your project.
Short range radars sense at 150m or less. At these short ranges extremely short pulses (meaning short in time duration, nS or pS in duration) are required to provide sufficient resolution to be useful. Short pulse, or impulse radar systems, generally follow a simple architecture where the impulse generator is often tied directly to a transmit antenna and a low noise amplifier (LNA) is tied to a receive antenna. A high speed digitizer is triggered off the impulse generator and acquires data on the output of the LNA.
You can incorporate impulse radar technology into your next project. Commercial versions of impulse radars are available to hobbyists and developers. Most notable are the ASIC based impulse radar manufactured by Novelda. These devices do require external antennas but contain on-board radar and high speed digitizers.
Additional impulse radar systems are being manufactured in quantity for automotive applications (blind spot detection, parking aids, etc), but details on these are not easy to find unless you directly engage the manufacturers. Manufacturers of automotive radar equipment include, Delphi, Continental, TRW, Bosch, Denso, and Autoliv.
Frequency Modulated Continuous Wave (FMCW) Radar
FMCW radar was originally used in radar altimeters starting in the 1930′s. Today, FMCW radar is the leading short-range radar architecture because it offers short-pulse radar resolution while providing significantly greater sensitivity with the same peak transmit power. This is because FMCW radars transmit continuously and leverage the discrete Fourier transform (DFT) to increase SNR in proportion to the time over which the DFT is applied. But for a hobbyist the key take-away is that these radars use a simple architecture and radar signals can be acquired by low-bandwidth digitizers such as the audio input port on your laptop, ADC input ports on micro controllers, the lower cost National Instruments NIDAQ units, etc.
For an FMCW radar, a CW oscillator is frequency modulated with a linear ramp. In other words, the CW oscillator starts at one frequency and ramps-up to a second over a relatively long period of time (0.5-10 uS). This waveform is radiated out of the transmit antenna towards the target scene. Some of this waveform is fed to the receiver mixer. What is scattered off the target is amplified by the LNA and fed into the receive mixer where it is mixed with the transmit waveform. The mixing product results in a low frequency (KHz range) beat tone that is proportional to range. The higher the frequency of beat tone the further the target. If measuring a multitude of targets then expect to see a multitude of beat tones superimposed on each other. To measure the range to targets you digitize with a low bandwidth digitizer being careful to synchronize the digitizer’s trigger with the start of the up-ramp. With this digitized data for each up-ramp, apply the DFT. This results in a time domain representation of the round trip time from transmitter, to targets, and back to receiver.
Add an FMCW radar to your next project. FMCW radar devices are available for developers and hobbyists. Some of the lowest cost FMCW radar devices are manufactured by RF Beam Microwave GmbH, who offers 24 GHz FMCW radar modules for less than $10 in quantity, shown here is a K-LC1.
In addition to this, you can build your own ‘Coffee Can Radar’ from the MIT Opencourseware site.
Not interested in building your own coffee can radar from scratch? You can buy a ready-made coffee can radar kit form Quonset Microwave. This radar provides data via a USB or BlueTooth.
And coming soon will be the radar Arduino shield! Credit for this belongs to Tony Long, who developed this shield loosely based on the MIT Coffee Can radar.
Add a radar sensor to your next project. It is not difficult to do with some basic understanding of architectures and signal processing. To learn more,
- teach yourself for free with the MIT OCW course,
- Pick up Gregory Charvat’s book: Small and Short-Range Radar Systems (use promo code EEE24 for discount),
- If you need help please visit the community forum which Greg set up.
- Want to learn fast and your employer is willing to pay for a short-course? Sign up to the MIT Professional Education Short-Course ‘Build a Small Radar System,’ and learn about small radar systems by making your own in 5 days. This was the top-ranked MIT Professional Ed course in 2011.
We can do this.
Soon small radar devices will be everywhere, let your project be one of the first!
Gregory L. Charvat, is author of Small and Short-Range Radar systems, co-founder of Butterfly Network Inc., visiting research scientist at the Camera Culture Group MIT Media Lab, and editor of the Gregory L. Charvat Series on Practical Approaches to Electrical Engineering. He was a technical staff member at MIT Lincoln Laboratory from September 2007 to November 2011, where his work on through-wall radar won best paper at the 2010 MSS Tri-Services Radar Symposium and is an MIT Office of the Provost 2011 research highlight. He has taught short radar courses at the Massachusetts Institute of Technology, where his Build a Small Radar Sensor course was the top-ranked MIT professional education course in 2011 and has become widely adopted by other universities, laboratories, and private organizations. He has developed numerous rail SAR imaging sensors, phased array radar systems, and impulse radar systems; holds several patents; and has developed many other radar sensors and radio and audio equipment. He earned a Ph.D in electrical engineering in 2007, MSEE in 2003, and BSEE in 2002 from Michigan State University, and is a senior member of the IEEE, where he served on the steering committee for the 2010 and 2013 IEEE International Symposium on Phased Array Systems and Technology and chaired the IEEE Antennas and Propagation Society Boston Chapter from 2010-2011.
Monday, February 24, 2014 - 16:01LuxBlaster: Blast a Beam of Light at the Most Intense Light Source
[Hazim] wrote in to tell us about his project that teaches inconsiderate drivers a lesson! Well, theoretically. The LuxBlaster is a spot light which points towards the most intense light source.
The idea is that you can blast drivers who do not turn their high-beams off with a reverse high-beam of your own. It is very important to note that this should never be used, as [Hazim] also clearly states. While this project is meant to prove that it can be done (a “what if”) project, it has two components that are very well done and can easily be used in different projects: the Arduino controlled spotlight and the light intensity tracker.
What would you use an Arduino controlled spotlight for? Smart lighting? What about a light source tracker? Let us know in the comments.
Filed under: Arduino Hacks
Monday, February 24, 2014 - 13:01BRAIGO – A Lego Braille Printer
Accessibility devices tend to be prohibitively expensive, and it’s always nice to see a hacker apply their skills to making these devices more affordable. BRAIGO is a low cost braille printer by [Shubham Banerjee]. He built the printer using parts from the LEGO Mindstorms EV3 kit, with a few additions. This LEGO kit retails for $349, and a standard braille printer costs over $2000.
The BRAIGO print head uses weights and a pin to punch holes in standard calculator paper rolls. LEGO motors are used to feed the paper and align the head for accurate printing. It takes about 5 to 7 seconds to print each letter, which are entered on the Mindstorms controller.
While this is a great prototype, [Shubham] intends to continue development with the goal of creating an affordable braille printer. He’s a bit swamped with media requests right now, but is working on releasing BRAIGO as an open source project so others can contribute. It’s an impressive project, especially for a 12 year old student. After the break, watch the BRAIGO do some printing.
Another Open Source braille related project we saw several years ago pipes digital chars to an Arduino powered braille terminal.
Filed under: tool hacks
Monday, February 24, 2014 - 10:00An Arduino Programmable Load
Having a big block of hot to dump current into is a very useful thing to have if you’re testing batteries, power supplies, high power LEDs, electroplating, or any thing else that would normally require a huge resistor. [Jakub] found himself in need of an electronic load, and instead of a transistor and a pot, decided to make something more automatic: a programmable load built around an Arduino shield.
The idea behind this load is pretty simple: connect a device to a FET and shunt resistor to measure current. Drive the gate of the FET with an op-amp that maintains either constant current or constant voltage. Control everything with a DAC, and you have a programmable load controlled by an Arduino.
With such a small form factor, getting rid of all that heat was bound to be a problem. For this, [Jakub] is using a 50×50 mm BGA style heat sink with a 5V fan. If it’s good enough for a big CPU, it should be able to handle dumping 70 Watts into a FET. There’s also a conservative application of thermal paste and a very small thermistor underneath the FET that’s able to be read by the Arduino. It might slowly heat up your room, but it’s not going to catch fire.
With the Arduino sketches [Jakub] wrote for his load he was able to characterize a pair of Idea batteries and figure out how much charge a three-year-old recyclable battery had. It’s a great piece of work, and if [Jakub] is willing to go through the hassle of a Kickstarter, it would make a fine crowdfunded product.
Monday, February 24, 2014 - 07:01The BitBox Console Gets Upgraded
The Bitbox, an open source game console, has received a number of updates in the past couple of months. Last time we covered this DIY console, [Makapuf] had just managed to get the first revision to run a simple game. The second revision will increase the colors to 32k, add another channel of sound for stereo, switch controllers from PS2 to USB, and add support for Olimex’s UEXT expansion devices.
While the hardware upgrades are impressive, there’s been a lot of work on the Bitbox software as well. A new game demo called Fire was created as a set of tutorials to help people start developing for the console. There’s also a BitBoy, a GameBoy emulator for the Bitbox. BitBoy is a ported version of gnuboy for the ARM Cortex-M4 processor that powers the Bitbox. It successfully emulates a number of commercial GameBoy ROMs.
We’re looking forward to seeing what’s next for the Bitbox. After the break, check out a video of BitBoy running on the Bitbox.
Monday, February 24, 2014 - 04:00SoundCube: A Companion Cube that can Talk
The Enrichment Center likely disapproves of the SoundCube: a portal music box in the form of a Portal Companion Cube. [Andreas] finished this project a couple of years ago, but we’re glad he’s finally had time to give a rundown on the details at his blog.
The build is primarily a modified speaker box cube—constructed out of what appears to be MDF—with four Alpine SXE-1725S speakers placed at the center of the middle faces. The faces were routed out to resembled the Companion Cube, while the electronics mount and the speaker grills were 3d printed. Inside is a homemade amplifier built around an Arduino Mega, with a TDA7560 quad bridge amplifier, a TDA7318 audio processor, a Belkin bluetooth receiver, and a 3.5″ touchscreen for volume control and for input selections.
Two 12v 7.2Ah lead-acid batteries keep the cube functional for an entire weekend of partying, but probably add a few pounds to the already hefty MDF construction. Check out [Andreas's] blog for more pictures and his GitHub for all the necessary code.
Monday, February 24, 2014 - 01:01Hackaday Links: February 23, 2014
You can pick up a tiny laser pointer on the cheap if you know where to look. But when it comes time to replace the multiple button cells that power it be prepared to clean our your wallet. [KB3WZZ] got around that with the cap from a ball-point pen. He drilled holes in the end plug of the pointer, and used wire and a plastic pen cap as a battery adapter. He’s powering it from USB, but now that you have wires exiting the case you can use any source you wish.
[Gerben] tipped us off about the trinket clone he built himself. It’s a tiny sliver of a PCB which he etched, populated with through-hole parts only, and finished off with some finger nail varnish to prevent shorting and corrosion. The solder-covered edge connector for USB was left unvarnished of course.
If you live in a college town you are probably quite used to seeing futon pads and frames on the curb waiting for the garbage collector. A little bit of ingenuity, and some added lumber, will turn a futon frame into a respectable shelving unit. [Thanks Martin]
Complicated bench equipment + good lighting + a great camera = an awesome teardown. This time around it’s the guts of a Keithly 2002 8.5 digit mulitimeter laid bare. [Thanks David]
Here’s a PCB laminator hack that is definitely worth a look. The original unit was acquired on eBay for about $25 and had a thermostat whose performance wasn’t optimal. A bit of alteration for the thickness of the substrate, and you’ll never hand iron a toner transfer board again! [Thanks William]
Last summer we heard about Scout, an ocean-going drone trying to cross the Atlantic. We just checked the live tracking and the craft is still at sea. But a much smaller 5ft vessel made it from New Jersey to Guernsey (an island between the UK and France) after traveling for about 14 months. [Thanks Rob]
Sunday, February 23, 2014 - 22:003D Printed RGB LED Bracelet
[Marcus's] 3D-printed LED bracelet has moved through a number of revisions recently, but each iteration is impressive in both simplicity and functionality. Inspired to experiment with his print of [nervoussystem's] Diagrid Bracelet, [Marcus] took the opportunity to add some LEDs with his first build, which combined a strip of RGB LEDs, a small battery, and an Adafruit Trinket microcontroller.
A second build soon followed, which overhauled the bracelet’s design into a more solid form and managed to double the amount of LEDs by upgrading to a different strip. The bracelet is currently in its third revision, cycling through the spectrum for around 3.5 hours on a single charge. This build also sports a 3-axis accelerometer: when the wearer shakes the bracelet, the colors skip around. If shaken long enough, the bracelet will enter a dazzling flurry of color flickering. Stick around after the break for a few demonstration videos. If you want to print your own, head over to [Marcus's] Thingiverse file.
Sunday, February 23, 2014 - 19:01Advanced Beer Carrier, or How To Get Beer Onto A Plane
[Badmonky] was facing a life crisis. How could he enjoy the hard-to-find German beers from his homeland while living in Princeton, New Jersey? Sure, you can find many good imports if you try, but that may come at a hefty price. Plus, the lesser known beers are completely unavailable in the States. Of course the solution is to import them himself after each trip home. He just needed a way to get as much beer on a plane as he possibly could.
We’d have no problem walking down the aisle with a couple of cases of cold ones, but let’s be honest here. Security won’t even let you on the plane with a bottle of water these days much less a case of tallboys. [Badmonky] hacked together this custom carrier so that it could be checked as luggage while protecting the frothy goodness. Two limiting factors to consider are size and weight. He started with the latter, calculating that 24 bottles would remain under his 50 pound limit. From there he selected a sports bag and picked up sheets of foam which were perforated using a hole saw. Alas the size constraint forced him to leave three of the (now empty?) vessels behind.
The bottles ride upside down and made the international voyage without incident. In retrospect he would have picked a roller-bag as this thing is hard on your shoulder after a trip through the airport and the public transit ride home.
The real question in our mind: why didn’t he check a keg?
Filed under: Beer Hacks
Sunday, February 23, 2014 - 16:00MobilECG goes open source
After a failed crowdfunding campaign, MobilECG has gone open source. MobilECG is a medical grade 12 lead electrocardiograph. A 12 lead system is quite a bit more complex than some of the ECG systems we have featured in the past. [Péter], the founder and designer of the device attempted to fund it through an Indiegogo campaign. While MobilECG is relatively cheap, medical certifications are not. The campaign didn’t reach its goal of $230,000 USD. [Péter] tried again with a grass-roots donation round at his website. That round also fell short of [Péter's] goal to keep working on the project. Rather than let his hard work go to waste, [Péter] has made the decision to release his hardware and software to the community. The hardware is licensed under CERN OHL v1.2. The software is released under the humorously named WTFPL.
While we’re not ECG experts, the basic hardware design appears to be sound. MobileECG is based around the Texas Instruments ADS1278 octal analog to digital converter. Two AVR microcontrollers are used, an ATTiny24, and an ATUC64. The analog design incorporates such niceties as lead off detection and defibrillator protection. It should be noted that there are some known bugs in the design, [Péter] mentions he can be contacted with questions. The software seems to be in an early state, and would require quite a bit of work to get it to a final design. While we do wish [Péter] had better luck with his campaign, we’re always glad to see designs released into the open source community.
Filed under: Medical hacks
Sunday, February 23, 2014 - 13:00Workbench With Built-In Solder Fume Extractor
There’s nothing quite like getting an eye full of solder fumes, but when it comes to solder fume extraction, the most common solution take up a whole lot of work area. Here’s a very clever solder fume extractor that doesn’t get in the way, and can be perfectly positioned over the acrid brimstone of a soldering station.
The build consists of a cheap bathroom vent fan built into the back of the workbench feeding into a long PVC pipe that blows the exhaust to the floor a few feet away. The fan is controlled by a simple wall switch, but the intake is where this build really shines. It’s a series of hard, flexible plastic segments that allow the intake to be precisely oriented above the work piece, or wherever it’s most convienent to suck solder fumes from.
This solder fume extractor is just a part of a really amazing electronics workbench. A lot of thought went into this workspace, from threaded inserts in the work surface to mount a panavise to an amazingly thoughtful equipment rack for computers, monitors, and other assorted heavy equipment.
via Hacked Gadgets
Filed under: tool hacks
Sunday, February 23, 2014 - 10:00Vintage DACs And A Raspberry Pi
Before the days of iPod docks in every conceivable piece of audio equipment, most devices were actually built very well. Most shelf top equipment usually came with well designed circuits using quality components, and late 90s CD players were no exception. [Mariosis] heard of some very nice DACs found in some of these units and decided to take one out for a spin. He’s using a Raspberry Pi to play audio with the DAC found in a late 90s Kenwood CD player.
After fortune favored a CD player with a dead drive on [Mariosis]‘ workbench, he dug up the service manual and found some interesting chips – a PCM56 DAC, a little bit of logic, and an SM5807 oversampling chip that does all the conversion for the DAC.
This oversampling chip uses an I2S – not I2C – bus to carry the data from the CD to the DAC. There is, of course, an I2S driver for the Raspi, but the first attempts at playing audio didn’t result in anything. It turned out there was a problem with what the oversampler expected – the ‘standard’ I2S signal delays the data one tick behind the LRCLK signal.
There are two ways to fix this problem: programming a kernel driver, or building some custom logic to fix the problem. Obviously breaking out some flip-flops and NOR gates was the cooler option, giving [Mariosis] a great sounding stereo with a vintage DAC.