sdr

310 Articles

Hackaday Links: September 21, 2012

September 21, 2012 by 31 Comments

And then Obi-wan said, “you were supposed to be the chosen one!”

Yesterday, a little bird told us Makerbot will be moving to a closed source model for their newest printer. This was confirmed, and now [Zach Smith] a.k.a. [Hoeken] – creator of the RepRap Research Foundation and co-founder of Makerboth Industries is weighing in with his take on the situation.

Hey! Free stuff!

Remember that DIP28 ARM chip with BASIC? Remember how I told you Coridium will be giving a few hundred away as samples? Yeah, that’s happening now.

Replacing a scroll wheel with titanium

[Rhett] has been using a Logitech mouse for a few years now. Recently the scroll wheel became corroded, so [Rhett] replaced it with a titanium version. The perfect match for the trusty battle axe, theIBM Model M keyboard.

Web-based IDE for the Raspi

[Phil Torrone] sent in a video of something he and [ladyada] are working on. It’s a web-based IDE for the Raspberry Pi. We’ll do a full review of this when it’s released.

Intro to software defined radio

So you have one of those TV tuner dongles and want to get in to software defined radio. Where do you start? [Al Williams] over at Dr. Dobbs has a great introduction to SDR, and gives a few pointers that should help you get that cool looking waterfall plot very quickly. Thanks for sending this in, [Chris].

Hackaday Links: September 7, 2012

September 7, 2012 by 17 Comments

MakerSlide, European edition

We’re all familiar with the MakerSlide, right? The linear bearing system that has been turned into everything from motorized camera mounts to 3D printers is apparently very hard to source in Europe. A few folks from the ShapeOko forum have teamed up to produce the MakerSlide in the UK. They’re running a crowdsourced project on Ulule, and the prices for the rewards seem very reasonable; €65/£73 for enough extrusion, v-wheels, and spacers to make an awesome CNC router.

Kerf bending and math

A few days ago, I made an offhand remark asking for an engineering analysis of kerf bending. [Patrick Fenner] of the Liverpool hackerspace DoES already had a blog post covering this, and goes over the theory, equations, and practical examples of bending acrylic with a laser cutter. Thanks for finding this [Adrian].

276 hours well spent

[Dave Langkamp] got his hands on a Makerbot Replicator, one thing led to another, and now he has a 1/6 scale model electric car made nearly entirely out of 3D printed parts. No, the batteries don’t hold a charge, and the motor doesn’t have any metal in it, but we’ve got to admire the dedication that went in to this project.

It was thiiiiiiis big

If you’ve ever tried to demonstrate the size of an object with a photograph, you’ve probably placed a coin of other standard object in the frame. Here’s something a little more useful created by [Phil]. His International Object Sizing Tool is the size of a credit card, has inch and cm markings, as well as pictures of a US quarter, a British pound coin, and a one Euro coin. If you want to print one-off for yourself, here’s the PDF.

Want some documentation on your TV tuner SDR?

The full documentation for the E4000/RTL2832U chipset found in those USB TV tuner dongles is up on reddit. Even though these chips are now out of production (if you haven’t bought a proper tuner dongle yet, you might want to…), maybe a someone looking to replicate this really cool device will find it useful.

Software-Defined Radio Remotely Using A Linux Wall wart

July 9, 2012 by 18 Comments

Here’s a interesting idea; if the hardware seen above is dropped at a location, you can monitor radio signals remotely via the Internet. [MS3FGX] has been toying with the idea for a little while now. He wanted to use a DVB dongle with a portable Linux solution to offer Software-Defined Radio (SDR) capability without the need to actually be there.

The white box is a PWN Plug, a branded version of the SheevaPlug. The black dongle that plugs into it is a DVB tuner dongle. It’s meant to receive television signals over the radio, but recently the hardware has been used as a simple way to implement SDR. Combine the two (along with the antenna), stir in a network connection, and you’ve got a remote listening post. What can you listen to? Just about anything that’s within the dongle’s bandwidth range. [MS3FGX] mentions walkie-talkie traffic and pager signals, to name just two.

He even wrote an installation script that gets you up and running in no time.

Adding More Frequencies To Your Software Defined Radio

July 8, 2012 by 32 Comments

[regveg] was looking for a way to receive signals outside the normal 64-1700MHz range his TV tuner software defined radio dongle can get. After finding a few $100+ upconverters on the Internet, he stumbled across a DIY project that greatly expands the frequencies his RTLSDR can receive.

[George]’s upconverter uses heterodyning to increase the frequencies received by a SDR dongle. The basic idea is mixing a signal from an antenna with a 100MHz frequency oscillator. The resulting output will be λ + 100MHz and λ – 100MHz, allowing for a wider range of frequencies that can be received by the SDR TV tuner dongle.

Now [regveg] has a board and schematic that makes it possible to receive just about anything with his TV tuner dongle. Interestingly, this upconverter contains less than $10 in parts and is easily etched at home thanks to a single-sided construction and through-hole parts.

As a small aside, [Andrew] sent in a tip a few days ago telling us his RTL dongle didn’t have any ESD protection. This is a very bad thing, but the good news is the fix is very cheap: just solder in a 10 cent diode and you’re good to go.

Putting A Software Defined Radio On A Mac

May 12, 2012 by 12 Comments

A few months ago [Antti Palosaari] discovered cheap USB TV tuners could be used as a software-defined radio. Since then, we’ve seen these TV tuners receive signals from GPS satellites and even the signals between air traffic control and passenger aircraft. Like everything cool, Mac support for these drivers is slightly terrible so [hpux735] wrote his own Cocoa app to support these amazing dongles.

[hpux735]’s driver is a port of the osmocom driver, repackaged as a native Cocoa app so the terribly fickle libusb and other dependencies aren’t needed. All the code is up on GitHub, ready for you to start playing around with SDR.

As far as tutorials for those wading into the deep waters of software-defined radio, a number of how-to guides have popped up over the last month to get SDR noobs up and running quickly. Here’s a few of the best ones we’ve seen:

[braingram] put up an Instructable for Ubuntu users.

For people who have a Windows box lying around [balint] put up a getting started guide.

There’s a slightly more thorough Windows guide here.

Most of the development in the TV tuner SDR community is happening on the RTLSDR subreddit, and there’s more than enough info there to do just about anything with these TV tuner dongles. If you come up with a novel use for one of these dongles, send it in on the tip line.

Playing Air Traffic Controller With Software Defined Radio

April 16, 2012 by 20 Comments

Being an air traffic controller is a very cool career path – you get to see planes flying around on computer screens and orchestrate their flight paths like a modern-day magician. [Balint] sent in a DIY aviation mapper so anyone can see the flight paths of all the planes in the air, with the added bonus of not increasing your risk of heart attack or stroke.

[Balint]’s Aviation Mapper uses software defined radio to overlay RADAR and ACARS messages from aircraft and control towers in an instance of Google Earth running in a web browser. After grabbing all the radio data from a software defined radio, [Balint]’s server parses everything and chucks it into the Google Earth framework. There’s a ton of info, pictures, and explanations of the inner machinations of the hardware on [Balint]’s official project page.

Right now, Aviation Mapper only displays planes within 500 km of Sydney airspace, but [Balint] is working on expanding the coverage with the help of other plane spotters. If you’re willing to help [Balint] expand his coverage, be sure to drop him a line.

Of course, [Balint] is the guy who gave us a software radio source block for those cheap USB TV tuner dongles. Just a few days ago we saw these dongles receiving GPS data, so we’re very impressed with what these little boxes can do in the right hands. [Balint] says his Aviation Mapper application will work with any GNU Radio receiver, so it’s entirely possible to copy his work with a handful of TV tuner dongles.

After the break, there’s two videos of [Balint] sitting at the end of the runway near the Sydney airport watching arrivials come in right above his head and on his laptop. It’s very cool, but we’d be interested in an enterprising hacker in the New York City area copy [Balint]’s work.

Continue reading “Playing Air Traffic Controller With Software Defined Radio” →

Those USB TV Tuners Used For SDR Can Also Grab GPS Data

April 13, 2012 by 23 Comments

Talk about versatile hardware. These inexpensive TV tuner dongles can also grab GPS data. You may remember seeing this same hardware used as a $20 option for software defined radio. But [Michele Bavaro] decided to see what other tricks they could pull off.

Would it surprise you that he can get location data accurate to about 20 centimeters? That figure doesn’t tell the whole story, as readings were taken while the dongle was stationary for three hours, then averaged to achieve that type of accuracy. But depending on what you need the data for this might not be a problem. And [Michele] does plan to implement real-time GPS data in his next iteration of the project. He plans to use an SDR acquisition algorithm to measure doppler shift in accounting for the slow clock speed of the dongles compared to standard GPS receivers. We can understand how that would work, but we’re glad he has the skills to actually make it happen because we’re at a loss on how the concept could be implemented.

[via Reddit]