Improving a software defined radio with a few bits of wire

Impressed by the recent advances in the software defined radio scene, [Jason] picked up a $20 USB TV tuner dongle to check out his local airwaves. Unfortunately, the antenna included with the little USB dongle is terrible at receiving any signal other than broadcast TV. [Jason] wanted to improve his reception, so he got some wire and made his own discone antenna.

The discone antenna is ideally suited for [Jason]’s setup – properly constructed, it’s able to receive over the entire 64 to 1700 MHz band the RTL-SDR dongle is able to read. To construct his antenna, [Jason] checked out [VE3SQB]’s list of antenna design programs, got the dimensions of his antenna, and set to work attaching wire to PVC pipe.

The antenna is a massive improvement over the stock antenna included with the TV tuner dongle. After mounting his discone at the far end of his back yard, [Jason] started picking up a few blips from the transponders of passing aircraft.

Amphi-Cycle lets you ride the trails, the waves, and back again

amphi-cycle

Hackaday regular [Berto] is always looking for new ways to get around, and wrote in to share his most recent creation, an amphibious bicycle.

He bought an off-the-shelf inflatable boat and constructed a rig that allows him to stably mount the bike on it. Once [Berto] comes across a body of water he wants to cross, all he requires is about 7 minutes time to inflate the boat and attach his bike. Using a modified version of his electric drill-based trolling motor we saw last year, the Amphi-cycle glides across the water effortlessly as demonstrated by his assistant in the video below.

Right now the boat is propelled solely by the trolling motor and a large lead-acid battery. We would love to see the amphi-cycle powered by its rider, though we don’t know how that would affect the “one boat fits all” design [Berto] is aiming for.

[Read more…]

Getting started with OpenCV

[Eric Gregori] sent in an article he wrote for EETimes to introduce the concepts behind computer vision to the masses. As a nice little bonus, [Eric] included a VMware image containing Ubuntu and all the packages and examples necessary to write your own OpenCV apps.

There’s a ton of awesome stuff you can do with computer vision – from automated sentries to keep squirrels away, a kitchen that will tell you when to do the dishes, and automating blindness by mounting a laser on a face tracker, there’s a lot of unexplored territory in the area of computer vision.

Included in [Eric]’s VM image are a motion and line detection example app, an ‘optical flow’ example, and a face detection example. There’s enough here to make a few very interesting projects, so hopefully, [Eric]’s VM image and examples will get your next CV project up and running quickly.

Accessing an SD card through a parallel port, just because

[Vinod] sent in a very cool build he says is somewhat of a ‘mad project’: he mounted an MMC and SD card under Linux using the parallel port on his computer. Even though parallel ports are getting rarer these days, we absolutely love [Vinod]’s dedication and willingness to dig around the Linux kernel.

The hardware portion of the build is very simple – just an SD/MMC header and a few resistors wired up to a parallel port. The software side of the hack gets pretty interesting with [Vinod] building a kernel module, something we rarely see on Hackaday.

We’d have to agree with [Vinod]’s ‘mad project’ sentiment, if only because of the terrible throughput of [Vinod]’s adapter; it takes him more than a minute to transfer a 1.5 MB file onto the SD card – terribly slow, to put it mildly. Nevertheless, we’ve got to respect [Vinod] for pushing the limits of uselessness and still building something cool in the process.

More pins and more power with a DIY Sanguino

Not long after [CulinarilySpeaking] got into the Arduino game, he began to want more IO pins and a larger program space for more ambitious projects. This, of course, led him down the path towards the Sanguino, the ATMega644-based dev board with many more IO pins than Arduino boards based on the ATMega328. Instead of buying new, [CulinarilySpeaking] decided to make his own Sanguino, and the results look fantastic.

After coming across an ATMega644 while browsing for parts on line, [CulinarilySpeaking] found the micro that had enough power and pins to do some fairly complex stuff. A bunch of other people though about using this chip in the Arduino environment before, so all [CulinarilySpeaking] had to do was copy the circuit with the parts he had on hand.

After soldering all the components to the neat breadboard-style PCB, [CulinarilySpeaking] fired up the Arduino IDE and put the Blink example on the 644. Everything worked, so now there’s a board with much more power than a standard Arduino built with only $8 USD in parts.

via reddit

Hackaday Links May 13th 2012

Amazing ass… for a robot

Yep, Japan still has the creepy robotics market cornered. Case in point is this robotic posterior. Don’t worry, they’ve included a dissection so you can see how the insides work too. [via Gizmodo]

Time-lapse camera module results

As promised, [Quinn Dunki] sent in a link to the photo album from her time lapse camera module. In case you missed it, she built it in a Tic Tac container and stuck it to the side of a racecar.

Kinect controlled killbot

Didn’t we learn anything from RoboCop? We could totally see this Kinect controlled robot (which happens to weigh five tons) going out of control and liquefying an unsuspecting movie extra standing near it. [via Dvice]

Laser popping domino balloons

apparently [Scott] has set a world record by using a laser to pop a line of 100 red balloons. We enjoy seeing the size of the 1W laser that does the popping… it can’t be long now before we get a hold of handheld laser pistols. [via Gizmodo]

Laser balloon targeting

If that last one was a bit of a let down, you might enjoy this automatic targeting system more. The blue triangle shaped icon is setting a target, the amber triangles have already been targeted. Once all the balloons are identified a laser quickly zaps each in order. Quite impressive, although no details have been provided. [Thanks everyone who sent in a link to this]

http://gizmodo.com/5909007/we-hope-lasers-popping-hundreds-of-balloons-is-the-new-dominos-fad