Last Mile WiFi Over TV White Space

May 17, 2011 by Mike Nathan 26 Comments

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What do you do when you can’t afford broadband and no-cost WiFi is just out of reach?

That was the problem Rice University grad student [Ryan Guerra] was tasked with solving. A local Houston resident could barely tap into the free service offered in her area, so [Ryan] set out to extend the signal’s range using white space previously occupied by TV signals.

Using channel 29 which operates at 563MHz, his “Super WiFi” project utilizes standard WiFi protocols and can extend the signal’s reach up to a mile. The WiFi signals at the closest tower are piped through a prototype frequency translator, shifting the signal from 2.4GHz down to 563MHz, which is far better suited for long(er)-haul transmissions. The system does not use channel bonding just yet, so it is limited to using about 25% of WiFi’s maximum bandwidth, which is far better than no signal at all.

While the widespread practical use of TV white space will take some time to come to fruition, this is definitely a step in the right direction.

[Thanks Chris]

Bluetooth Media Remote In An N64 Controller

May 14, 2011 by Caleb Kraft 5 Comments

[Phik] wrote in to share his very first microcontroller project with us. He built a bluetooth remote in an old Nintendo 64 controller to control an audio application on his computer. He had been building up the individual modules with the controller in mind for some time, but initially had no idea what kind of enclosure to put it in. After a failed attempt at stuffing it into an XBox controller(surely there was enough space), he realized he had a broken N64 controller lying around that he cold use. We think he did a fantastic job of mounting it, it looks almost like a commercial product. He documented the construction and testing of each individual module. You can find each of those broken into their own post on his site by checking out the archives. Great job [Phik], especially for your first project!

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Large Remote-controlled Game Of Life Display

May 3, 2011 by Mike Nathan 5 Comments

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Sometimes it’s just plain fun to over-engineer. [Stephanie] gets a warm fuzzy feeling when she successfully adds way more electronics components to a project than she really needs – just because she can. We can’t really argue with her if that is the intended goal, nor can we find fault with the sweet Game of Life display she put together.

She started off with six Game of Life kits from Adafruit, but she quickly caught the LED bug and her collection grew until she had 20 kits (that’s 320 LEDs for those of you keeping count). After piecing them all together, they were mounted in a wooden frame and placed behind a dark piece of acrylic. It looked great and worked just fine, but it wasn’t overdone enough for her tastes.

In the end, she added a small Arduino and Xbee module to the Game of Life display, which enables it to be controlled by her network-enabled thermostat we featured a few weeks back. The thermostat was fitted with an Xbee unit as well, which allows it to turn the Game of Life on and off at whatever times [Stephanie] specifies.

We’ll take two please.

[via Adafruit Blog]

Tactical Wifi Cantenna Needs Picatinny Rails

April 15, 2011 by Jesse Congdon 17 Comments

[Wes] built a cool looking Tactical Wifi Cantenna with some parts from a broken airsoft pistol. The antenna is a cookie can type with an added cone to increase performance, as seen in this tutorial. Once the antenna was built it was time to add some kind of handle, [Wes] just so happened to have such a thing on hand. After epoxy puddying the pistol’s grip to his cookie cantenna he observed that the magazine lock was still functioning. Quick thinking and the application of a hammer in nut allows the whole rig to quickly attach to the tripod. The antenna also sports a plastic lid and textured paint finish for that ultimate tactical look and feel. A USB Alpha AWUSO36H Wifi dongle even mounts on the back of the rig. We wouldn’t go around outside pointing this at stuff attaching and detaching the tripod but the finish looks great, nicely done!

Check out some other various types of cantennas, even a rifle version if you crave more wifi goodness.

Reverse Engineering LED Vodka Bottle Displays

April 6, 2011 by Mike Nathan 10 Comments

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When [Tyler] heard about the LED matrix display that Medea Vodka was building into their bottles, he immediately wanted to get his hands on one. Who could blame him? Someone had finally combined two things we love dearly: booze and LEDs.

He struggled to find a bottle at any of his local stores for the longest time, but was absolutely stoked when he finally came across one of their reps promoting the brand while he was out shopping.

Once he got home, he pulled the display off the bottle and began poking around to see what made it tick. The display is made from a flexible PCB, and attached to the bottle with some clear elastic film. It is powered by two CR2032 batteries and controlled by a PIC16F chip, which pulls stored messages from a small Atmel EEPROM.

Once he figured out how to control the LED matrix, he uploaded his own fonts and added a LINX wireless module to remotely send messages to the board. He mounted it in a wooden frame and now uses it as a simple marquee display.

If you have one of these displays hanging around your house, be sure to swing by his site for schematics of his wireless interface board as well as the code he uses to drive the marquee. You can check out a video of the display in action there as well.

Transmitting Power And Data Through Thick Metal Enclosures

April 1, 2011 by Mike Szczys 49 Comments

So let’s say you have a submarine, or a nuclear containment chamber which has walls made of thick metal. Now let’s say you want to transmit power or data through this wall. Obviously you’re not going to want to drill a hole since this wall is either keeping seawater out, or potential contamination in, but wireless signals aren’t going to travel well through dense metal. [Tristan Lawry’s] entry in the Lamelson-MIT Rensselaer Student Prize seeks to address this issue by using ultrasound waves to transmit data and power.

In the video after the break [Tristan] speaks briefly about his project, then demonstrates the transmission of power and digital audio simultaneously through a two-inch thick steel plate. This is accomplished with a set of piezo transducers attached to both the inside and outside of the plate. Communications originate by feeding electricity to one transducer, which sends ultrasonic vibrations through the material to be received by its counterpart on the other side. It’s easy for us to understand data transmission conducted in this manner, after all that’s how the knock block receives information. What we don’t understand is how it can “transfer large amounts of electrical power”. If you can explain it in layman’s terms please do so in the comments.

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Wireless Luge Timer Levels The Playing Field

March 29, 2011 by Mike Nathan 3 Comments

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In Colorado, amateur luge competitions are serious business.

Every winter, [Ryan’s] friends dig a long luge track through the many feet of snow that occupies their yard, and have competitive sled races to see who can make it down the giant hill in the least time. They call it the Mario Cup, after one of the participants, not the Nintendo mascot, and they were in desperate need of some timing equipment.

You see, the luge track is several hundred feet long, and they decided that a human armed with a stopwatch is not a good enough means of picking a conclusive winner. A set of three Arduino sensors packed inside plastic food containers were used along with light sensors to track when the luger passed the start, midpoint, and finish lines of the race. XBee radios then transmitted the timing data back to the base station for recording.

The system worked quite well according to the participants, and they look forward to using the system again in the future. Of course, improvements have been planned, including dual timers at each checkpoint to gauge the luger’s speed, as well as a Christmas-tree starting signal like you see at drag races.

Continue reading to see a video below of the luger’s in action, as well as the timer system undergoing some tests.

[via Make]

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