[Angelo] is only 15, but that doesn’t mean his fabrication skills are limited to Lego and K’Nex. He’s built himself an amazingly well constructed FM transmitter that’s powerful enough to be received a quarter mile away.
The FM transmitter circuit itself is based off one of [Art Swan]‘s builds, but instead of the solderless breadboard construction you would expect to find in a small demo circuit, [Angelo] went all the way, etching his own PCB and winding his own coil.
Using photosensitized copper clad board, [Angelo] laid out the circuit with Fritzing, etched a board, and went at it with a drill. The components found in the transmitter are pretty standard and with the exception of the trimmer cap and electret mic, can be picked up in the parts drawers of any Radio Shack. He gets bonus points for using a 1/4 – 20 bolt for winding the coil, too.
The power supply for the transmitter is a single 9V battery, the battery connector being salvaged from a dead 9V. Awesome work, and for someone so young, [Angelo] already seems to have a grasp of all the random, seemingly useless information that makes prototyping so much easier. Video below.
While Arduino and its libraries are the quickest way to interface with a sensor and blink an LED, sometimes you shouldn’t have to write and compile code to do something exceptionally simple. [Oliver] realized most of the overly simple functions of a microcontroller could be done from a command line running on that microcontroller and came up with the MiniPirate, the Arduino command line tool.
The MiniPirate is just a sketch compiled on the Arduino that allows pins to be set high or low, set a PWM value, or reading and writing I2C bytes. It’s basically an extremely slimmed down version of the Bus Pirate meant for extremely simple modifications of circuits and peripherals.
[Oliver] demos his MiniPirate by taking a DS1307 real-time clock, wiring up the I2C bus, and writing values to set the time. It’s a very simple implementation meaning he needs to write everything in hex, but it’s still easy enough to find a use in many other projects.
Long range wireless control of a project is always a challenge. [Mike] and his team were looking to extend the range of their current RC setup for a UAV project, and decided on a pair of Arduino mini’s and somewhat expensive Digi Xtend 900Mhz modems to do the trick. With a range of 40 miles, the 1 watt transceivers provide fantastic range. And paired with the all too familiar Arduino, you’ve got yourself an easy long range link.
[Mike] set the transmitter up so it can plug directly into any RC controller training port, decoding the incoming signal and converting it into a serial data package for transmitting. While they don’t provide the range of other RF transmitters we’ve seen, the 40 mile range of the modem’s are more than enough for most projects, including High Altitude Balloon missions.
The code for the Arduino transmitter and receiver sides is available at their github. Though there is no built-in error correction in the code, they have not had any issues. Unfortunately, a schematic was not provided, but you should be able to get enough information from the images and datasheets to construct a working link.
Here’s another of those ‘why did it take so long’ products, that make total sense. What could be easier than to hook your car alarm system up to the vehicle’s standard OBD connector (typically a socket under the steering wheel in the foot well area), to make it instantly trackable?
The idea behind CarLock is simple. Immediately the car is moved, the system will alert you on your smartphone via a standard GSM SIM card inside [...]
iOS: The popular Game Boy Advance emulator, GBA4iOS has been updated to version 2.0 and now works without requiring a jailbreak or any crazy workarounds. On top of GBA emulation, you'll also get support for Game Boy and Game Boy Color.
Moving around in space is one of the major hurdles in virtual reality. A holodeck wouldn’t be much fun if you kept walking into walls. [Gamnaught] is working on a simple solution to this complex problem with his budget omnidirectional treadmill. Omnidirectional treadmills have been around in various forms for a number of years. The idea behind them simple: allow a person walk in any direction without actually changing their position. This is a bit different from the unidirectional treadmill models found at the local gym. Some very complex solutions have been used to create omnidirectional treadmills, including multiple motors and computer control systems as can be found in the US Army omnidirectional treadmill. [Gamnaught] kept it simple. He built a circular 2×4 platform 13-15 degree bowl. The bowl is covered with carpet, and the user wears furniture sliders on their shoes. The low friction of the sliders allows the user to walk, run, and even walk backwards on the platform. Bungie cords provide resistance so the user doesn’t walk off the platform.
The early results look promising. [Gamnaught] says the balance felt a bit weird at times and took some getting used to. Anyone who has spent time with the Oculus Rift or other VR systems will tell you – many aspects of virtual reality take some getting used to. The treadmill is still open loop, however [Gamnaught] hopes to add motion tracking with a Sixense STEM system. We think a OpenCV based system would work as well. We’ve also seen carpet sliders sold as a children’s toy to be strapped over regular sneakers. Going the toy route would avoid needing a dedicated pair of footwear for the treadmill. More build information can be found on [Gamnaught's] Reddit thread on the topic.
Cells printed in a grid pattern by block cell printing technology (left) and woodblocks used in ancient Chinese printing (right) (credit: Lidong Qin lab and Digital Museum of Science and Art, Beijing, China)
A new way to print living cells onto any surface and in almost any shape has been developed by researchers led by Houston Methodist Research Institute nanomedicine faculty member Lidong Qin.
Unlike a similar inkjet printing process, almost all cells survive.
The new process, called Block-Cell-Printing (BloC-Printing), produces 2-D cell arrays in half an hour, prints the cells as close together as 5 microns (most animal cells are 10 to 30 microns wide), and allows the use of many different cell types.
“Cell printing is used in so many different ways now — for drug development and in studies of tissue regeneration, cell function, and cell-cell communication,” Qin said. “Such things can only be done when cells are alive and active. A survival rate of 50 to 80 percent is typical as cells exit the inkjet nozzles.
“By comparison, we are seeing close to 100 percent of cells in BloC-Printing survive the printing process.”
BloC-Printing manipulates microfluidic physics to guide living cells into hook-like traps in the silicone mold. Cells flow down a column in the mold, past trapped cells to the next available slot, eventually creating a line of cells in a grid.
The position and spacing of the traps and the shape of the channel navigated by the cells is fully configurable during the mold’s creation. When the mold is lifted away, the living cells remain behind, adhering to the growth medium or other substrate, in prescribed formation.
Qin’s group tested BloC-Printing for its utility in studying cancerous cells and primary neurons. By arranging metastatic cancer cells in a grid and examining their growth in comparison with a non-metastatic control, the researchers found they could easily characterize the metastatic potential of cancer cells.
“We looked at cancer cells for their protrusion generation capability, which correlates to their malignancy level,” Qin said. “Longer protrusion means more aggressive cancer cells. The measurement may help to diagnose a cancer’s stage.”
The researchers also printed a grid of brain cells and gave the cells time to form synaptic and autaptic junctions.
“The cell junctions we created may be useful for future neuron signal transduction and axon regeneration studies,” Qin said. “Such work could be helpful in understanding Alzheimer’s disease and other neurodegenerative diseases.”
While it is too early to predict the market cost of BloC-Printing, Qin said the materials of a single BloC mold cost about $1 (US). After the mold has been fabricated and delivered, a researcher only needs a syringe, a carefully prepared suspension of living cells, a Petri dish, and a steady hand, Qin said. Inkjet cell printers can cost between $10,000 and $200,000.
“BloC-Printing can be combined with molecular printing for many types of drug screening, RNA interference, and molecule-cell interaction studies,” he said. “We believe the technology has big potential.”
While the fidelity of BloC-Printing is high, Qin said inkjet printing remains faster, and BloC-Printing cannot yet print multi-layer structures as inkjetting can.
Qin and postdoctoral fellow Kai Zhang, Ph.D., are BloC-Printing’s co-inventors.
Support was provided by the National Institutes of Health, the Cancer Prevention and Research Institute of Texas, the U.S. Dept. of Defense, the Emily Hermann Research Fund, the Golfers Against Cancer, and the Alliance for Nanohealth.
In addition to his position in the Houston Methodist Research Institute’s Department of Nanomedicine, Qin is also a Weill Cornell Medical College assistant professor of cell and developmental biology.
Abstract of Proceedings of the National Academy of Sciences paper
A unique live-cell printing technique, termed “Block-Cell-Printing” (BloC-Printing), allows for convenient, precise, multiplexed, and high-throughput printing of functional single-cell arrays. Adapted from woodblock printing techniques, the approach employs microfluidic arrays of hook-shaped traps to hold cells at designated positions and directly transfer the anchored cells onto various substrates. BloC-Printing has a minimum turnaround time of 0.5 h, a maximum resolution of 5 µm, close to 100% cell viability, the ability to handle multiple cell types, and efficiently construct protrusion-connected single-cell arrays. The approach enables the large-scale formation of heterotypic cell pairs with controlled morphology and allows for material transport through gap junction intercellular communication. When six types of breast cancer cells are allowed to extend membrane protrusions in the BloC-Printing device for 3 h, multiple biophysical characteristics of cells—including the protrusion percentage, extension rate, and cell length—are easily quantified and found to correlate well with their migration levels. In light of this discovery, BloC-Printing may serve as a rapid and high-throughput cell protrusion characterization tool to measure the invasion and migration capability of cancer cells. Furthermore, primary neurons are also compatible with BloC-Printing.
[Bithead's] already built some home automation to control the lighting and temperature in his house while he’s away, but he wanted to take things a step further and have the house automatically anticipate his arrival and adjust the environment accordingly. The project takes advantage of geofencing to create a perimeter around the home that listens for a transceiver in [Bithead's] car. We featured a similar project with a Raspi a few months ago, which locked the doors upon driving away.
[Bithead's] implementation uses a pair of Digi Xbee Pro XSC radios with U.FL antennas to provide an impressive 2+ mile range of communication. The home-based Xbee hooks up to a Parallax Xbee USB adapter and subsequently into his computer—its antenna sits in a nearby window on the top floor of his house to maximize range. For his car, [Bithead] originally opted for an Xbee shield and an Arduino Uno, but he’s recently overhauled the build in favor of an Arduino Fio, which reduced the footprint and increased the range. Check out his page for the build log specifics and more pictures.
We've seen a lot of standing desks, including those made from IKEA parts, but artist/designer Kelli Anderson managed to make one of the nicest convertible options yet. With IKEA storage furniture, Google Sketchup, and help from some friends, she was able to make this simple and stunning workspace with plenty of room for everything—regardless of how she wanted to work.
The lowly Arduino, an 8-bit AVR microcontroller with a pitiful amount of RAM, terribly small Flash storage space, and effectively no peripherals to speak of, has better speech recognition capabilities than your Android or iDevice. Eighty percent accuracy, compared to Siri’s sixty.Here’s the video to prove it.
This uSpeech library created by [Arjo Chakravarty]
uses a Goertzel algorithm to turn input from a microphone connected to one of the Arduino’s analog pins into phonemes. From there, it’s relatively easy to turn these captured phonemes into function calls for lighting a LED, turning a servo, or even replicating the Siri, the modern-day version of the Microsoft paperclip.
There is one caveat for the uSpeech library: it will only respond to predefined phrases and not normal speech. Still, that’s an extremely impressive accomplishment for a simple microcontroller.
This isn’t the first time we’ve seen [Arjo]‘s uSpeech library, but it is the first time we’ve seen it in action. When this was posted months and months ago, [Arjo] was behind the Great Firewall of China and couldn’t post a proper demo. Since this the uSpeech library is a spectacular achievement we asked for a few videos showing off a few applications. No one made the effort, so [Arjo] decided to make use of his new VPN and show off his work to the world.
Did you know you can generate electricity with a candle? We are using this method to power a fan. It works great and the energy is FREE! Get a free Hulu Plus trial at: http://huluplus.com/household
You can get a Peltier cooler here for pretty cheap: http://amzn.to/Jtl6D9
What kinds of devices would you power with this? Let us know in the comments!
How much extra vacuuming though ?
I ordered and received my Bug-a-salt gun late last fall, pretty late in the fly season to really get to put it to serious use. Well, early spring in Western Washington and they are coming back. Over the years I became very proficient with rubber bands, hunting flies and yellow jackets – this takes it to a whole new level.
The Bug-a-salt doesn’t “cream” the flies, leaves them pretty well intact, but it is quite effective. Non-toxic, environmentally friendly, it is spring powered and doesn’t eat batteries. Just table salt.
The gun has sights, but due to the shot pattern and the height of the sights above the bore for me it is a “point and shoot” proposition. A sheet of aluminum foil taped to the wall works well to pattern the shot, like a patterning board for a shotgun. It lets you see the spread of the salt, and calculate your effective range. I am definitely getting better. It is possible to shoot flies out of the air. There is nothing else like it.
The invention and marketing of this product are a story unto itself. I ordered mine early, when they were setting up for manufacture and was able to follow the trials and tribulations of getting this to market. The exportation to some of the countries they had orders from were amazingly complicated.
This year I switched to Morton Kosher salt and find it works better on flies than the table salt. Last year’s tests on yellow jackets were exciting, but not effective. Maybe with the kosher salt…
-- Norm Bolser
Available from Amazon
This is the best introduction to ultralight backpacking there is. Ultralight means you carry less than 25 pounds of gear, food and water for a 10 day trip, and maybe less than 5 pounds for a weekend trip! That’s liberating. If you obsessively reduce the mass of things (or leave them behind) by onefold then you can raise your enjoyment of hiking tenfold.
But most of the stuff in a backpack is carried to overcome a lack of knowledge. So whenever you take away weight you have to replace it with knowledge — knowledge that this book supplies.
This book assumes you are persuaded of this zen-like way. If you need to be persuaded that carry-weight is worth obsessing over, or you want the full course of every option available, and the evidence and reasons for each method, and how to make all the stuff yourself, then you’ll need Ray Jardines’ bible on the subject, the previously reviewed and now updated Beyond Backpacking/Trail Life.
But instead of a bible, this fantastic book by Mike Clelland will give you cartoons. Lot’s of them.
It’s jammed packed with dense, informative, easy to digest, and remarkably helpful advice, hints and instructions on how to accomplish and enjoy walking with very little stuff — and this knowledge is mostly compressed into witty cartoons. I am a big fan of Clelland’s other previously reviewed cartoon guides to snow travel and ordinary backpacking and I really like how amazingly effective his drawings are. Each one is worth thousands of words. It’s fun but not silly. Clelland grapples with the real-world details of, say, not taking a water filter or toilet paper (!!!) and his solutions are born of many seasons of experience. The whole book is authentic and reliable. It will very quickly have you out on the trail carrying a lot less than you once did. Even if you don’t get as extreme as he does, you can move in the right direction by substituting knowledge for stuff. I’ve been going super light for a long time and I learned tons of new tricks on almost every page.
Ultralight Backpackin’ Tips
2011, 144 pages
Available from Amazon
I tried dehydrating a 1 quart jar of kimchi. It produced about 30 grams of dried kimchi which I blended into powder. Now I could use your help from this point. What should I combine this delicious kimchi powder with? I've put it on popcorn, I can see it being used as a alternative to vegetable stock, what else? Mixed drinks, ice cream, salads?