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!
Tuesday, February 25, 2014 - 01:00Astronaut Mae Jemison on interstellar travel: ‘We can’t do this with just half the population’
Astronaut Mae Jemison is a true inspiration for women everywhere and her message from the MAKERS Conference on women leadership is one that is powerful and resounding. Via the next web.
At the MAKERS Conference on women leadership this week, Google[x] VP Megan Smith, astronauts Cady Coleman and Mae Jemison and Harvey Mudd President Maria Klawe took the stage to discuss the importance of increasing the number of women in the Science, Technology, Engineering and Mathematics (STEM) fields.
Jemison, who is the first African-American woman to go to space, emphasized that, as women become a greater part of STEM education and industries, it’s important for women to be in the room “helping to make the choices.”
She talked about her involvement with the 100 Year Starship project, which aims to send humans on an interstellar journey in the next 100 years, and how an endeavor of that magnitude must be a team effort.
“We can’t do this with just half the population,” she said.
Jemison continued with a quote from authors Will and Ariel Durant: “The future never just happened. It was created.”
“We have an opportunity to create the future and decide what that’s like,” Jemison added.
Tuesday, February 25, 2014 - 00:00Packbot: Serving the Military and World Cup Football #robotics
Robohub has the story about the new security measures being taken for the World Cup this year.
PackBots will be deployed in Brazil during the 2014 World Cup Soccer season to bring a high-tech approach to security. The nation’s government has secured a $7.2 million deal with PackBot’s creators for 30 of the military bots. The robots will be stationed throughout Brazil’s 12 host cities, during the soccer matches to boost security and help examine any suspicious objects.
The sleek PackBot robot system, designed by iRobot, a Bedford, Massachusetts-based company, made its debut in 2002 in Afghanistan, where it helped soldiers clear bunkers, caves, collapsed building and to cross minefields. The versatile machine was used again in 2003 in Iraq in urban warfare situations and to search vehicles. By 2007, more than 800 of these military robots were in use throughout Afghanistan, Iraq and several other countries. The PackBot was also the first remote controlled robot to enter the Fukushima nuclear facility after the East Japan Earthquake and tsunami in March 2011.
PackBot is a unique robotic propulsion system that can reach a road speed of up to 9 miles/hour. The bot’s in-built flippers allow it 360 degrees of rotation, enabling it to negotiate rough terrain and even obstacles like logs, rocks, rubble and stairs. PackBot has the capability to climb up to 60 percent grades and survive submersion in water up to two meters depth.
Its robust body can survive a fall from a two meter height to a concrete surface, being flung through a window and falling downstairs. This bot weight less than 40lbs, and is easily carried in a back pack, ready to be deployed within minutes.
PackBot’s other attributes include a state-of-the-art GPS, video image display, system monitoring, electronic compass, temperature sensors. The robot is manipulated with an integrated Pentium-based computer.
Monday, February 24, 2014 - 23:54Apple Extended Keyboard II Hack #ArduinoMicroMonday @arduino #arduino
I’m lucky enough to own an Apple Extended Keyboard II, which belongs to my Macintosh SE. Unfortunately, it wasn’t doing much good connected to my rarely-used SE. So, I figured it would find a better home on my desk at work, where I spend the day pounding away on a crummy keyboard anyway.
The Apple Extended Keyboard II is a dream to type on because it uses mechanical switches. And I lucked out: Apple made a lot of revisions of this keyboard with cheap switches, but it turns out that I got one of the good ones. Mine is a USA model with authentic Alps Cream key switches.
The biggest stumbling block to the project was the computer’s interface. The Apple Extended Keyboard II is from the days of ADB, or Apple Desktop Bus. The internet revealed two possible solutions: An expensive and sometimes-hard-to-find adapter by Griffin, or a $16 microcontroller and some DIY elbow grease. Naturally, I chose the latter.
Here is the official press release for the Arduino Micro in collaboration with Adafruit.
Arduino Micro in collaboration with Adafruit
Arduino Micro board – Based on the technology behind the Leonardo board, its main feature is the very small size.
The Arduino Micro packs all of the power of the Arduino Leonardo in a 48mm x 18mm module (1.9″ x 0.7″).
It makes it easier for makers to embed the Arduino technology inside their projects by providing a small and convenient module that can be either used on a breadboard or soldered to a custom designed PCB.
The Micro has been developed in collaboration with Adafruit Industries, one of the leaders of the Maker movement. Adafruit is already developing a series of accessories for the new board that will complement its power and simplicity.
Throughout the month of November the product is available exclusively from Adafruit online and Radio Shack in retail stores.
Main features of Arduino Micro:
- The Arduino Micro is a microcontroller board based on the ATmega32u4.
- Like its brother the Leonardo board, the Arduino Micro has one microcontroller with built-in USB. Using the ATmega32U4 as its sole microcontroller allows it to be cheaper and simpler. Also, because the 32U4 is handling the USB directly, code libraries are available which allow the board to emulate a computer keyboard, mouse, and more using the USB-HID protocol.
- It has 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a micro USB cable to get started.
- This allows the Micro to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.
- Microcontroller: ATmega32u4
- Operating Voltage: 5V
- Input Voltage (recommended): 7-12V
- Input Voltage (limits): 6-20V
- Digital I/O Pins: 20
- PWM Channels: 7
- Analog Input Channels: 12
- DC Current per I/O Pin: 40 mA
- DC Current for 3.3V Pin: 50 mA
- Flash Memory: 32 KB (ATmega32u4) of which 4 KB used by bootloader
- SRAM: 2.5 KB (ATmega32u4)
- EEPROM: 1 KB (ATmega32u4)
- Clock Speed: 16 MHz
Arduino, the first widespread Open Source Hardware platform, was launched in 2005 to simplify the process of electronic prototyping. It enables everyday people with little or no technical background to build interactive products.
The Arduino ecosystem is a combination of three different elements:
- A small electronic board manufactured in Italy that makes it easy and affordable to learn to program a microcontroller, a type of tiny computer found inside millions of everyday objects.
- A free software application used to program the board.
- A vibrant community, true expression of the enthusiasm powering the project. Every day on the www.arduino.cc website thousands of people connect with other users, ask for help, engage and contribute to the project.
About Adafruit Industries
Adafruit was founded in 2005 by MIT engineer, Limor “Ladyada” Fried. Her goal was to create the best place online for learning electronics and making the best designed products for makers of all ages and skill levels. Since then Adafruit has grown to over 25 employees in the heart of NYC. Adafruit has expanded their offerings to include tools and equipment that Limor personally selects, tests and approves. Adafruit has one of the largest collections of free electronics tutorials, open-source hardware and software to help educate and inspire the next generation of scientists and engineers.
Monday, February 24, 2014 - 23:15littleBits Projects: Shoes
Send your littleBits circuits out into the world wearing SHOES! Now you can hold your circuits together and place them on any surface. Try magnet shoes on your refrigerator, hook & loop shoes on your dog’s collar, or adhesive shoes for more permanent installations. Check out the projects below for inspiration and be sure to visit our Shoes Tips & Tricks Page for more ideas.
Magnet Shoes in Action
Make a mailbox indicator light. This circuit sits directly on your metal mailbox (due to magnet shoes) and signifies when mail is placed inside. When letters are placed on top of the roller switch, the long LED on the exterior of the box shines bright. Out with the flag and in with the long LED! littleBits circuit: power + roller switch + wire + bright LED.
Hook & Loop Shoes in Action
Shoes on shoes — secure your circuit to a pair of sneakers to make these Stomping Shoes. The light wire lights up whenever you stomp down due to a sound trigger. All you need to do is stick an adhesive velcro adhesive strip to the sneaker, add hook & loop shoes to your circuit, lace up the light wire and start dancing.
Make a light-up dog collar! Design your circuit (we used a power module, a sound trigger, wires, and bargraphs) and lock it together with hook & loop shoes. Sew parts sections of a velcro strip to the collar, position the circuit, and watch the collar light up when your dog barks.
Adhesive Shoes in Action
Using adhesive shoes, secure your synth circuit to any material and make an instrument. We made a Keytar! The adhesive on the shoes sticks nicely to the acrylic surface of our keytar and holds the modules snugly in place.
Need some littleBits shoes in your life? Click here
Monday, February 24, 2014 - 23:00Prototyping a pressure sensor with Arduino Micro #ArduinoMicroMonday
John Thomson managed to build a pressure sensor to behave like a switch, when it’s in an idle state the LED is off, if you apply some pressure, light goes on:
The pressure pad doesn’t just work straight out the box – it requires a little bit of craft. What I’ve done is sandwich a pressure sensitive conductive sheet – known as Velostat – between two pieces of felt. I then stitched some conductive thread through each piece of felt – this applies a current to the pad and when the sandwich is put together, the circuit is complete. The Velostat acts like a resistor – the value changes when pressure is applied. It’s then just a case of writing out code that tells the LED to come on when the pressure reading goes over a certain threshold.
Monday, February 24, 2014 - 23:00New Project: Mini Blind Minder #arduino
Steve Hoefer uses Arduino to create temperature activated blinds! via Make:
Sometimes the sun is my friend, warming the house on cool days. Other times it’s my enemy, warming the house on hot days. Blinds are one solution to this problem, but it seems that no matter how I set my blinds before I leave for the day, the weather changes and I come home to a sweltering or freezing house.
So I built this mini blind minder to open and close them automatically. It’s powered by an Arduino microcontroller, which uses a temperature sensor to read the room temperature and then activates a servomotor to open the slats when it’s too cool and close them when it’s too warm. It has an adjustable thermostat and it can also be operated manually to open or close your blinds with a push of a button.
You’ll solder a custom Arduino “shield” — a circuit board with headers that plug into the Arduino — and then mount it all in a tidy RadioShack project case. This project requires only a moderate amount of soldering, so you can easily build it in a day or a weekend.
For a step by step tutorial read more
Monday, February 24, 2014 - 22:54@bekathwia & @adafruit nominated for Best in “Maker” in Social Media @shortyawards #diy #maker #SHORTYAWARD
Calling all real life MacGyvers’ out there! Can you make almost anything out of almost anything then love to share it on social? Do you use social media site such as Twitter, YouTube, Tumblr, Vine, Instagram, and Facebook to share tips and advice for others to make great inventions and constructs out of raw materials? The winner of the #Maker Shorty Award will be a someone who finds #DIY projects fascinating, and enjoys learning and loves sharing what they can do. Nominate who you think should win the #Maker Shorty Award now!
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 - 22:00After 400 years, mathematicians find a new class of solid shapes
The Hindu has the exciting story on a new class of solid shapes.
The work of the Greek polymath Plato has kept millions of people busy for millennia. A few among them have been mathematicians who have obsessed about Platonic solids, a class of geometric forms that are highly regular and are commonly found in nature.
Since Plato’s work, two other classes of equilateral convex polyhedra, as the collective of these shapes are called, have been found: Archimedean solids (including truncated icosahedron) and Kepler solids (including rhombic polyhedra). Nearly 400 years after the last class was described, researchers claim that they may have now invented a new, fourth class, which they call Goldberg polyhedra. Also, they believe that their rules show that an infinite number of such classes could exist.
The new discovery comes from researchers who were inspired by finding such interesting polyhedra in their own work that involved the human eye. Stan Schein at the University of California in Los Angeles was studying the retina of the eye when he became interested in the structure of protein called clathrin. Clathrin is involved in moving resources inside and outside cells, and in that process it forms only a handful number of shapes. These shapes intrigued Schein, who ended up coming up with a mathematical explanation for the phenomenon.
During this work, Schein came across the work of 20th century mathematician Michael Goldberg who described a set of new shapes, which have been named after him, as Goldberg polyhedra. The easiest Goldberg polyhedron to imagine looks like a blown-up football, as the shape is made of many pentagons and hexagons connected to each other in a symmetrical manner (see image to the left).
However, Schein believes that Goldberg’s shapes – or cages, as geometers call them – are not polyhedra. “It may be confusing because Goldberg called them polyhedra, a perfectly sensible name to a graph theorist, but to a geometer, polyhedra require planar faces,” Schein said.
A crude way to describe Schein and Gayed’s work, according to David Craven at the University of Birmingham, “is to take a cube and blow it up like a balloon” – which would make its faces bulge. The point at which the new shapes breaks the third rule – which is, any point on a line that connects two points in that shape falls outside the shape – is what Schein and Gayed care about most.
Craven said, “There are two problems: the bulging of the faces, whether it creates a shape like a saddle, and how you turn those bulging faces into multi-faceted shapes. The first is relatively easy to solve. The second is the main problem. Here one can draw hexagons on the side of the bulge, but these hexagons won’t be flat. The question is whether you can push and pull all these hexagons around to make each and everyone of them flat.”
During the imagined bulging process, even one that involves replacing the bulge with multiple hexagons, as Craven points out, there will be formation of internal angles. These angles formed between lines of the same faces – referred to as dihedral angle discrepancies – means that, according to Schein and Gayed, the shape is no longer a polyhedron. Instead they claimed to have found a way of making those angles zero, which makes all the faces flat, and what is left is a true convex polyhedron.
Monday, February 24, 2014 - 21:05The New Maker City: Cleveland
Monday, February 24, 2014 - 21:00Light Up Thor Costume
Superheroes seen in comic books often have unrealistic proportions. Women are given big chests, and men get giant muscles. Though it’s not necessary to match a character’s physique when you cosplay, you can add bulk if you want to. Instructables user spiderball built a Thor costume for Halloween, and he used craft foam to build up his arms to Norse-god like proportions:
I wanted my arms to have a bit more size so with the 1/8th [inch] craft foam I cut segments to create the muscle groups of the arm. These groups were then hot glued together giving me a fake arm which started at the top of my shoulder down to the wrist.
This was trial and error to get the size and shape you want. I started with a bicep to get the scale for the rest of the arm. The first picture is of the shoulder, I placed it over my actual shoulder and moved around to make sure I had enough room. The next picture is from the shoulder to elbow, once again I slipped it on to make sure it was to scale and I could move in it.
Once both arms were constructed I coated them in contact cement and then placed on a layer of cheese cloth. This gives strength to the seams to prevent tearing. Next I cut out 3/4″ squares and covered the arms from shoulder to mid forearm, the squares are craft foam and hot glued on.
Read more at Instructables.
Monday, February 24, 2014 - 21:00Cosplay Interview with Sarcasm-hime
Besides being amazed by the resourcefulness and maker skills cosplayers possess, I’m often impressed with how helpful they are. Many people who make and create are willing to pass on knowledge or answer a question, and cosplayer Sarcasm-hime (featured on Adafruit here) does so through several tutorials on her website. She’s created several costumes ranging from the Scarlet Witch to Arwen to Death and learned all kinds of skills along the way. It’s easy to lose track of time while browsing her site to look and costumes and her tips and tricks.
We talked with Sarcasm-hime about what inspired her to cosplay, why it’s important for her to share knowledge, and more.
Adafruit: You have a dazzling array of costumes. How long have you been cosplaying and what inspired you to start?
Sarcasm-hime: I’ve been cosplaying since 1999; I was interested in sewing and costuming before that but I didn’t find out about fandom and cons until ’97, at which point my head exploded in a “HOW DID I NOT KNOW ABOUT THIS MAGICAL THING” kind of way and I never looked back. Having an excuse to make fancy things and play dress-up multiple times a year (while hanging out with other nerds in fancy clothes) is pretty much my idea of heaven.
I started for the same reasons that most cosplayers do – it’s fun to dress up as your favourite characters. That said, there’s a saying “There are two kinds of cosplayers – anime fans who like to wear costumes, and costumers who like anime.” I’m definitely one of the latter, as for me a huge part of the appeal for cosplay is the creative process, the problem-solving, learning new things and the feeling of accomplishment at completing something difficult/time-consuming.
Adafruit: I noticed your site contains a section with several tutorials. How-tos take time to create; why is it important for you to share your knowledge with other cosplayers?
Sarcasm-hime: When I started cosplaying there weren’t a lot of tutorials available. These days you can find a tutorial for pretty much anything quite easily, but back before YouTube it was really hard to find any resources or helpful instructions for cosplay. Others helped me out when I was first starting, and I felt it was really important to ‘pay it forward’ and share what I learned with others. My tutorials are pretty basic compared to a lot of the stuff out there now, but I still do get emails from time to time thanking me for them, which gives me massive warm fuzzies.
This is one reason I love Costume-Con so much; it’s a con devoted entirely to sharing costuming techniques, and it’s full of costume nerds like me who love to ogle each other’s crazy obsessive details. There’s always something new to learn.
Photo by Stillvisions
Adafruit: What new skills have you acquired over the years of cosplaying?
Sarcasm-hime: I’ve learned a lot, mostly by trial and error (see above comment about lack of tutorials). I knew basic sewing when I started, but since then I’ve learned draping, embroidery, beading, woodworking, prosthetic makeup, corsetry, metal casting, mascot construction, wig styling and (very) basic electronics, among others. For me half the fun of cosplaying is figuring out how to bring a 2-D design to life, so I try to always choose something that will challenge me in some way.
Sadly, one of the skills I still haven’t acquired is the ability to come up with a really funny and/or awesome skit. I decide to make a costume because it looks awesome and/or I relish the challenge of making it, and then at some point a week or two before the con I have to come up with something to do onstage, which usually ends up being ‘swan about the stage showing off my pretty dress’. Fortunately I have awesome friends to help out with the skit ideas.
Adafruit: Which costume so far has presented the biggest challenge and why?
Sarcasm-hime: That would probably be a costume that I’m still working on now – Garuda from Final Fantasy XI. I chose the design because it involves techniques that I haven’t used before (making giant wings with a harness, digitigrade legs), and has proven to be quite daunting. I’m hoping to get it done sometime this summer.
Besides that, though, it would probably be Moondragon; I hadn’t worked with Worbla or electronics before, and the method I came up with for attaching the wings and the spine turned out to be trickier than anticipated. For most of my costumes I plan out early how I’m going to do pretty much everything; it just often involves months of fiddly detail work (if that counts as a challenge?).
Adafruit: What advice would you offer to people who want to try cosplaying for the first time?
Sarcasm-hime: Firstly, choose a costume that’s going to make you happy; ideally happy making it and happy wearing it.
Secondly, when starting out I advise choosing a design that fits your skills. Evaluate what you think you can manage and how much time you have, and then pick something that is feasible. Don’t bite off too much right at the start, especially before you have a sense for how long it will take you to make things. Rushing to finish costumes while AT the con and not getting any sleep sucks and is no fun. I’ve done it too many times and swore never again!
There are tons of tutorials out there now, so search for tips and instructions. That said, a big part of the fun of cosplay is problem-solving. If you can’t find a tutorial that matches exactly what you’re aiming to do, experiment!
I have more advice on my site.
Monday, February 24, 2014 - 20:29New Project: Making a Simple Soundboard with Raspberry Pi
Monday, February 24, 2014 - 20:00Stretchable optical circuits could find use in robot skin and more
More on the future of flexible electronics from gizmag.
If flexible electronic devices are ever going to become practical for real-world use, the circuitry incorporated into them will have to be tough and resilient. We’re already seeing progress in that direction, including electrical wires that can still carry a current while being stretched. However, what if the application calls for the use of fiber optics? Well, scientists from Belgium may have that covered, too. They’ve created optical circuits utilizing what they believe are the world’s first stretchable optical interconnections.
The idea is that devices such as wearable sensors or touch-enabled robot skin could utilize standard glass fiber optic cables for the most part, but could use the interconnections to bridge gaps between those cables, allowing the device to bend or lengthen at those locations.
Made from a clear rubbery substance known as PDMS (poly-dimethylsiloxane), the interconnections feature a transparent core through which the light travels, that’s surrounded by an outer layer of the same material. Because light doesn’t move as easily through that outer layer due to its lower refractive index, the design keeps the light signals contained within the core.
In lab tests, the interconnections were able to guide light signals when stretched by up to 30 percent, or when bent around an object with a diameter as small as that of a human finger. What’s more, they maintained that functionality after being mechanically stretched by 10 percent a total of 80,000 times.
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 - 19:007 STEM Toys from the 2014 Toy Fair
Among the piles of plush toys, dolls and cars on display at the 2014 International American Toy Fair this year, there was a new standout category: STEM toys.
STEM — an acronym that refers to science, technology, engineering and mathematics — is becoming increasingly popular as parents opt for educational toys that instill these basics at an early age.
Monday, February 24, 2014 - 18:52Intel’s ‘Make It Wearable’ Challenge Accepting Submissions
In our video above, Mary Huang of Continuum Fashion asks viewers “what if you could change the world with one powerful idea?” In this case Huang hints at the myriad applications of wearable technology in our near future, when, as Huang poses, advancements will become a “personal and seamless” part of daily life.
Intel supports this revolution in wearable tech and the creators fueling it. As part of their Make It Wearable challenge, starting February 24th Intel will be collecting submissions to help promote and explore the next big ideas in the field.
The VISIONARY track, the first contest Intel will be rolling out this year, rewards those that think big–recognizing ideas and projects with the potential to radically change the way we live. To enter, creators must submit a 1-minute video detailing innovative ideas, to be chosen in 5 rounds throughout the year. These ideas will then be judged by a panel of experts, and evaluated on their potential for innovation. Finalists from each round will be featured on the Make It Wearable website, and winners will receive $5,000 in seed funding to help get them started. Finalists will also be invited to the Make It Wearable presentation and gala event to be held in San Francisco.
Monday, February 24, 2014 - 18:10Ode To A Lump Of Putty I’m Gonna Make Stuff With
Monday, February 24, 2014 - 18:06Ask your Wearables Questions! LIVE Wearable Electronics with Becky Stern 2/26 2pm ET
What questions do you have about wearable electronics? Ask them now in the comments, and you could win our live giveaway!
All inquisitive askers whose questions are featured on this week’s LIVE Wearable Electronics with Becky Stern will be eligible for a special giveaway. Post your Qs in the comments here, on Google+, Twitter, or YouTube, and then tune in at 2pm ET on Wednesday for the answers and to see if you’ve won!