Sunday, April 6, 2014 - 19:01Reusable Vacuum Bag Saves you Money
Vacuum dust bags are annoying. They’re expensive, one time use, and if you have an older vacuum cleaner, good luck finding replacements! [Karl] got fed up so he decided to make his own reusable dirt bag instead.
He’s using an old t-shirt as the new bag material but notes that you can use any other sufficiently drafty material as well — as long as it stops the dust but lets air through, you’re good! To seal the bag he’s using a piece of rubbery vinyl with a hole cut in it to seal against the intake pipe. This is sewn to the t-shirt with a piece of cardboard sandwiching the fabric. From there it’s just a matter of adding a zipper or Velcro, and you’re done!
He’s been using this filter for over a year and hasn’t had any problems with it yet — you can even wash it! While you’re at it, why not make a wet-spill attachment for your vacuum cleaner too?
Filed under: green hacks
Sunday, April 6, 2014 - 16:00VCF East: The Swyft Card
Ninety five percent of the population will say Apple computers is the brainchild of [Steve Jobs]. The other five percent will be right, but what nearly no one knows is that the Macintosh project was originally conceived by [Jef Raskin]. He holds the honor of turning the Mac into an, ‘information appliance’ and being one of the first people to seriously consider how millions of people would interact with computers.
The Mac wasn’t [Jef]‘s first project at Apple, though. Before the Mac project he was working on something called Swyft – an easy to use command line system that was first implemented as a firmware card for the Apple IIe. [Mike Willegal] was kind enough to bring one of these Swyft cards to the Vintage Computer Fest this weekend, and did a demo of it for us.
The basic idea behind the Swyft card was to have an integrated word processor, calculator, and access to Applesoft Basic. Holding down a ‘leap’ key – in the case of the Apple IIe add-on, the open apple key – allowed the user to search for text and perform operations on any result. It’s odd, but it just makes sense in some strange way.
[Mike] is doing a build class at the VCF today where anyone attending can build their own Swyft card. He also has instructions for building your own, should you want to experiment with one of the ‘could have beens’ of user interface design.
Filed under: classic hacks
Sunday, April 6, 2014 - 15:08Why UPS Trucks Don’t Turn Left #makerbusiness
UPS engineers found that left-hand turns were a major drag on efficiency. Turning against traffic resulted in long waits in left-hand turn lanes that wasted time and fuel, and it also led to a disproportionate number of accidents. By mapping out routes that involved “a series of right-hand loops,” UPS improved profits and safety while touting their catchy, environmentally friendly policy. As of 2012, the right turn rule combined with other improvements — for the wow factor, UPS doesn’t separate them out — saved around 10 million gallons of gas and reduced emissions by the equivalent of taking 5,300 cars of the road for a year.
Sunday, April 6, 2014 - 14:39Controlling a lock with an Arudino and Bluetooth LE
This project allows you to open a solenoid lock from a PhoneGap app using theBluetooth Serial Plugin and the new Adafruit Bluetooth LE break-out board for the Nordic Semiconductor nRF8001 chip.
Our Adafruit Bluefruit LE (Bluetooth Smart, Bluetooth Low Energy, Bluetooth 4.0) nRF8001 Breakout allows you to establish an easy to use wireless link between your Arduino and any compatible iOS or Android (4.3+) device. It works by simulating a UART device beneath the surface, sending ASCII data back and forth between the devices, letting you decide what data to send and what to do with it on either end of the connection.
And pick one up in the Adafruit store!
Sunday, April 6, 2014 - 14:35Open Source Hardware and the Future of Embedded Systems – Bunnie’s slides from EELive! (PDF) #oshw
Sunday, April 6, 2014 - 13:01CPLD Tutorial: Learn Programmable Logic the Easy Way
The guys over at hackshed have been busy. [Carl] is making programmable logic design easy with an 8 part CPLD tutorial. Programmable logic devices are one of the most versatile hardware building blocks available to hackers. They also can have a steep learning curve. Cheap Field Programmable Gate Arrays (FPGA) are plentiful, but can have intricate power requirements. Most modern programmable logic designs are created in a Hardware Description Language (HDL) such as VHDL or Verilog. Now you’ve got a new type of device, a new language, an entirely new programming paradigm, and a complex IDE to learn all at once. It’s no wonder FPGAs have sent more than one beginner running for the hills.
The tutorial cuts the learning curve down in several ways. [Carl] is using Complex Programmable Logic Devices (CPLD). At the 40,000 foot level, CPLDs and FPGAs do the same thing – they act as re-configurable logic. FPGAs generally do not store their configuration – it has to be loaded from an external FLASH, EEPROM, or connected processor. CPLDs do store their configuration, so they’re ready as soon as they power up. As a general rule, FPGAs contain more configurable logic than CPLDs. This allows for larger designs to be instantiated with FPGAs. Don’t knock CPLDs though. CPLDs have plenty of room for big designs, like generating VGA signals.
[Carl] also is designing with schematic capture in his tutorial. With the schematic capture method, digital logic schematics are drawn just as they would be in Eagle or KiCad. This is generally considered an “old school” method of design capture. A few lines of VHDL or Verilog code can replace some rather complex schematics. [Carl's] simple designs don’t need that sort of power though. Going the schematic capture route eliminates the need to learn VHDL or Verilog.
[Carl's] tutorial starts with installing Altera’s Quartus II software. He then takes the student through the “hardware hello world” – blinking an LED. By the time the tutorial is done, the user will learn how to create a 4 bit adder and a 4 bit subtractor. With all that under your belt, you’re ready to jump into big designs – like building a retrocomputer.
[Image via Wikimedia Commons]
Sunday, April 6, 2014 - 10:01Creative Continuity Tester Made For a Few Bucks
No multi-meter? For troubleshooting most household things, a continuity tester is extremely handy. And as it turns out, you can make your own from the dollar store for next to nothing.
[Carlyn] shows us how to make two different styles of continuity testers — a light up version using a bicycle light, or a buzzer version using one of those cheap window alarms. The leads are made of 1/8″ audio cables — and everything for both these testers cost less than $5 from their local dollar store. It’s a very simple build process that you can probably figure out just from this one photo, but [Carlyn] has also taken pictures of every step along the way.
Compared to building one of these out of components from Radio Shack, this method is much more MacGyver, and cheap! Hooray for taking advantage of mass produced consumer products!
Filed under: tool hacks
Sunday, April 6, 2014 - 08:00Computers teaching other computers how to play Pac Man
Would you like to play a game… of Pac Man? Researchers from Washington State University have developed a way for a computer to “teach” another computer how to play the video game.
Researchers have developed a method to allow a computer to give advice and teach skills to another computer in a way that mimics how a real teacher and student might interact. Researchers had the agents — as the virtual robots are called — act like true student and teacher pairs: student agents struggled to learn Pac-Man and a version of the StarCraft video game. The researchers were able to show that the student agent learned the games and, in fact, surpassed the teacher.
Sunday, April 6, 2014 - 07:01University Attempts to Break 3D Printing World Record
LeTourneau University attempted to set a 3D printing Guinness World Record yesterday. They had 50 3D printers print the same thing at the same time. Impressive? Kind of, but not really.
LulzBot — our favorite 3D printer company — saw this and thought “that’s cute — we run over 50 printers a day on a normal basis!”. So just for lulz, they decided to film a little counter-record video featuring 109 LulzBot 3D printers running simultaneously.
To be honest, we kinda feel sorry for LeTourneau University — but it looks like LulzBot really takes the cake here. The university has a really cool policy for their engineering students though — all incoming freshmen students are required to build their own 3D printer for school. Whoa! To be honest it is a really cool way to force you to get out of your comfort zone and learn a bit about several different engineering disciplines.
To follow along the discussion and status of the record, a thread is going on over at 3Dprintboard.com. Stick around to see the video of LulzBot’s drool worthy server racks filled with identical printers.
Filed under: 3d Printer hacks
Sunday, April 6, 2014 - 07:00E-Tattoos Can Now Store Data and Administer Medication
E-tattoos, ultra thin, stretchable electronics worn on the surface of the skin, are now capable of more than just basic biometric readings like heart rate monitoring. Now, researchers have made developments that allow them to store data and even automatically administer medicine. From Motherboard:
The problem with e-tattoos so far has been powering them and allowing them to do long-term data storage. The advancement of nanotechnology, however, has allowed researchers to create e-tattoos that use less power and are finally able to store data.
Powering the thing is still a problem—Son’s e-tattoos are connected to an external power source worn on the body (say, a battery placed in your pocket), but the data storage problem has been solved by using what’s known as resistive random access memory (RRAM), created using exceedingly small nanomembranes. For the first time, e-tattoos can actually store and use information.
That’s a big deal, because it opens up new possibilities for the usefulness of e-tattoos, especially in diagnostics and drug delivery. Instead of sticking one on so that you can use Bluetooth to connect the vibrations of your throat with your phone for better voice-command clarity, we can imagine a scenario where e-tattoos are used to trigger the release of drugs into the bloodstream or something like that.
Similar to the nanovolcano concept shown a few months ago, such devices could be useful for people with chronic conditions. In fact, Son even designed a wearable skin patch that could automatically deliver drugs when necessary and tested it on pigs.
Sunday, April 6, 2014 - 06:00Tiny New Brain Implant Could Help Paralysis Victims Walk Again
This tiny little device could make huge things possible! From Digital Trends:
Researchers at the A*Star Institute of Microelectronics in Singapore have developed a neural probe array small enough that it can sit inside someone’s brain on a long-term basis without damaging delicate tissue. The probe array is so compact that it can float along with a person’s brain inside their head. Their specialty: helping amputees and people with spinal cord injuries control artificial limbs.
The neural array forms a link between the brain and artificial limbs, allowing someone with an injury to walk or move again. As the technology advances, who knows what else they could allow us to do.
Sunday, April 6, 2014 - 04:00Super Mario on a Human-Machine-Interface!
Getting Super Mario to work on your TI-83 calculator is almost a rite of passage for young geeks, so we really liked this project where [Chad Boughton] managed to get it running on a PLC’s HMI screen instead!
He’s using a Danfoss DP600LX microcontroller with an HMI display along with a CAN bus joystick. This kind of equipment is typically used to control hydraulic systems, as well as display sensor data — [Chad] was curious to see if he could do animation with it as well — it looks like he’s succeeded! The funny thing is we’ve seen those “joysticks” before and it’s cool to see them used for something like this — like [Chad] said, they’re normally used for actuating hydraulic and pneumatic cylinders.
Stick around after the break to see Mario eat some mushrooms.
There’s almost too many Mario hacks to mention here, so we’ll just pick a few — Ever heard the Mario theme song played on a laser cutter? It’s as awesome as it sounds. And for a true Super Mario veteran… can you play it backwards?
Sunday, April 6, 2014 - 01:26We’re back! Welcome to the new Adafruit.com and new learn.adafruit.com
We’re back! Welcome to the new Adafruit.com and new learn.adafruit.com – thanks for your patience and support while we did a BIG update to our sites, we’re currently working on some odds and ends and will have some updates shortly, stay tuned
Sunday, April 6, 2014 - 01:01Gesture Recognition Using Ultrasound
You’d be hard pressed to find a public restroom that wasn’t packed full of hands free technology these days. From the toilets to the sinks and paper towel dispensers, hands free tech is everywhere in modern public restrooms.
The idea is to cut down on the spread of germs. However, as we all know too well, this technology is not perfect. We’ve all gone from sink to sink in search of one that actually worked. Most of us have waved our hands wildly in the air to get a paper towel dispenser to dispense, creating new kung-fu moves in the process. IR simply has its limitations.
What if there was a better way? Check out [Ackerley] and [Lydia's] work on gesture recognition using ultrasound. Such technology is cheap and could easily be implemented in countless applications where hands free control of our world is desired. Indeed, the free market has already been developing this technology for use in smart phones and tablets.
Where a video camera will use upwards of 1 watt of power to record video, an ultrasound device will use only micro watts. IR can still be used to detect gestures, as in this gesture based security lock, but lacks the resolution that can be obtained by ultrasound. So let us delve deep into the details of [Ackerley] and [Lydia's] ultrasound version of a gesture recognizer, so that we might understand just how it all works, and you too can implement your own ultrasound gesture recognition system.
Most of us are aware of the Doppler Effect – the compressing and stretching of waveforms as the source moves toward or away from a point. Consider a device that consists of a tone generator above the 20kHz human ear threshold (ultrasound) and a microphone transducer that would react to reflections of the ultrasound waveform. If an object, such as a hand, were moving toward the device, the reflected waveform would experience a Doppler shift. Such a shift would be seen by the microphone. The same would happen if the object were moving away from the device. This frequency shift can be calculated by:
In order to determine if an object is moving toward or away from the device, you must compare the outgoing and incoming frequencies. [Ackerley] and [Lydia] decided to use the Fast Fourier Transform equation to do this – the same technique used by Microsoft’s Sound Wave, which inspired their project. Unfortunately their assigned processor, the Atmel 1284p, would not be able to handle the Fast Fourier Transform AND signal acquisition at the same time. It was just not fast enough. Stumped, their instructor suggested a clever idea. An idea that will open up gesture recognition via ultrasound to the world of the 8 bit micro controller. You see, instead of doing the frequency comparison on the resource limited digital side, do it on the analog side with an AD633 Analog Multiplier IC (pdf warning).
It turns out that if you multiply two sine waves, you will get two different products. One will be the difference and the other will be the sum of the two waveforms. There is beauty in this. Our paradigm has shifted. This single 8 pin IC can determine the difference in frequency between the incoming and outgoing signals. Consider an outgoing frequency of 24kHz. Now consider a hand moving toward the device creating a Doppler shifted frequency of 24.1kHz. The output of the AD633 would be 1kHz and 48.1kHz. The 48.1kHz is easily filtered away and you are left with the 100Hz, or the difference between the incoming/outgoing frequencies that an 8 bit micro controller can easily sample.
Now a keen eye will see that the Doppler shifted frequency only reveals magnitude, and not direction. [Ackerley] and [Lydia] solve this problem by observing subtle changes in amplitude of the difference frequency. Many more details of how this is done can be found in the linked article. The image below show’s their algorithm in the Atmel detecting a “pull” motion.
The genius of this project is that a viable gesture recognition system can be implemented with cheap components. The approach of doing a similar system with a PC or smart device would be different. We would like to see the microcontroller side pushed further. Imagine a system in an elevator where the passenger could “draw” the number to the floor he or she wanted to go to. Or a paper towel system that would dispense towels as we twirled our hand, and stop when we stopped twirling. Or a sink that could change water temperature with a simple gesture. Such systems, using the technology designed by [Ackerley] and [Lydia], should be possible.
Saturday, April 5, 2014 - 22:01Open Source Power Line Communication
Since we all have wires running throughout our houses to provide mains power, there’s a number of devices that piggyback on mains lines for communication. For his thesis project, [Haris Andrianakis] developed his own power line communication system.
The basic principle of the system is to inject a signal onto the power lines at a much higher frequency than the 50 or 60 Hz of the AC power itself. Using both active and passive filters, the signal can be separated from the AC power and decoded. This system uses frequency-shift keying to encode data. This part is done by a ST7540 modem that’s designed for power line applications. The modem is controlled over SPI by an ATmega168 microcontroller.
[Haris]‘ write up goes into detail about some of the challenges he faced, and how to protect the device from the high voltages present. The final result is a remote display for a weigh scale, which communicates over the power line. Schematics, PCB layout, and software are all available.
Saturday, April 5, 2014 - 19:01The Mobile Phone PixelSWaLL
As much as we hate to admit it, smart phones have become somewhat of a disposable item in today’s society. People upgrade their phones constantly and simply chuck their old ones. Of course, there’s plenty of things you can do with slightly out of date phones… Here’s one we haven’t seen before — a wireless multi-phone display!
It’s called the PixelSWaLL, and according to the author, his software can control up to 240 Android devices! To run this demo with just 9 phones, he’s using an old Apple Macbook running Windows 7 bootcamp, which sends the display info using an old Telmex router. Each phone or tablet runs the Android terminal application using Eclipse ADT which renders OpenGL in real-time. The server application was made with Delphi 7 and uses the DSPack library to read video files in order to send them over UDP via Indy 10. It’s a bit of a mouthful to explain, but the resulting display array is pretty cool!
Time to start collecting phones…
Filed under: Android Hacks
Saturday, April 5, 2014 - 17:04Site updates and more today!
Site updates and more today! We appreciate your support and patience as we update and upgrade Adafruit! See you soon!
Saturday, April 5, 2014 - 16:01Bike Pedals in Both Directions, Gets You to Your Destination AND Back
[punamenon2] has built an interesting bike that moves forward regardless if it is pedaled forward or backwards! What? Yes, you read that correctly. Pedal forward or backwards and the bike goes forward. This project started off as any old cruiser with a free-wheeling rear hub. To pull off this mod a second free-wheel and sprocket had to be added to the current wheel assembly. One free-wheel and sprocket set is used when pedaling forward, the other set is used when pedaling in reverse. There is also a new chain tensioner that serves to not only keep the chain taut but also allows for the chain to change directions which ultimately allows this novel idea to work.
Confused? Here’s how it works:
When pedaling in the forward direction, the bike acts as a normal bike does where top of the Crank Sprocket pulls the chain and the chain then pulls on the top of the Large Wheel Sprocket. This turns the rear wheel in the forward direction. The portion of the chain that wraps around the Small Wheel Sprocket is traveling in the backward (CCW) direction which doesn’t cause a problem because it is a freewheel, just like how you can pedal backwards on a bike while coasting forward. Since there are two different sized Wheel Sprockets, pedaling in the forward direction is the higher of the two gears.
When pedaling backwards the chain moves in the opposite direction. The bottom of the Crank Sprocket pulls the chain forward which in-turn pulls on the top of the Small Wheel Sprocket. This also turns the rear wheel in the forward direction. The portion of the chain that wraps around the Large Wheel Sprocket is now traveling in the backward (CCW) direction, and again doesn’t cause a problem because it is freewheel.
Why did [punamenon2] decide to do this? Just for fun! And that is a good enough reason in our book.
Filed under: transportation hacks
Saturday, April 5, 2014 - 13:01Taking Pictures with a DRAM Chip
This picture was taken by using a DRAM chip as an image sensor (translated). A decapped 64k DRAM chip was combined with optics that could focus an image onto the die. By reading data out of the DRAM, the image could be constructed.
DRAM is the type of RAM you find on the RAM cards inserted into your motherboard. It consists of a massive array of capacitors and transistors. Each bit requires one transistor and one capacitor, which is quite efficient. The downside is that the memory needs to be refreshed periodically to prevent the capacitors from discharging.
Exposing the capacitor to light causes it to discharge faster. Once it has discharged past a certain threshold, the bit will flip from one to zero. To take a picture, ones are written to every bit in the DRAM array. By timing how long it takes a bit to flip from one to zero, the amount of light exposure can be determined. Since the DRAM is laid out in an array, each bit can be treated as a pixel to reconstruct the image.
Sure, modern CCDs are better, cheaper, and faster, but this hack is a neat way to totally re-purpose a chip. There’s even Turbo Pascal source if you’d like to recreate the project.
Thanks to [svofski] for the tip.
Filed under: digital cameras hacks
Saturday, April 5, 2014 - 10:01Web Interface for the FRAM LaunchPad
The Internet of Things is here in full force. The first step when adding to the Internet of Things is obvious, adding a web interface to your project. [Jaspreet] wrote in to tell us about his project that adds a web interface to his MSP430 based project, making it easy to add any project to the internet of things.
Creating a web interface can be a bit overwhelming if you have never done it before. This project makes it easy by using a dedicated computer running Linux to handle all of the web related tasks. The LaunchPad simply interfaces with the computer using USB and Python, and the computer hosts the webpage and updates it in real time using Node.js. The result is a very professional looking interface with an impressively responsive display that can control the on-board LEDs, read analog values from the integrated ADC, and stream accelerometer data. Be sure to see it in action after the break!
Filed under: internet hacks