There are a lot of options out today for streaming video to your Internet-connected devices. Whether it’s Hulu, Netflix, Slingbox, or the late Aereo, there is no shortage of ways to get your TV fix. However, [Jaruzel] wasn’t happy with any of these services and wanted a more custom solution, so he built his own TV-streaming box out of hardware he had lying around.
[Jaruzel] gets TV from a service called SkyTV, but wanted to be able to stream it to his tablet, laptop, and XBMC. While rummaging through his parts bin, he came up with a WinTV tuner card for capturing TV and a Mini-ITX board to process everything and stream it out over his network.
Once the computer was put in a custom enclosure, [Jaruzel] got to work installing Puppy Linux. He wrote a boot script that configures the WinTV card and then starts VLC to handle the streaming service which allows him to view the TV stream over HTTP on the network. This is a great hack that would presumably work for any TV stream you can find, even if it’s just an over-the-air source.
In need of a kitchen entertainment system, [BoaSoft] headed to the parts bin and produced a project that can easily be called a mutant. That being said, we love the results!
Here’s the link to the original Russian language post. If your Russian is a bit rusty here’s a really awful machine translation. So let’s see if we can decipher this hack.
Sounds like [BoaSoft] had a broken Acer laptop on hand. Problem was the laptop can’t play over-the-air television (and similarly, a television can’t surf the net). The solution was to figure out how to utilized a TV tuner of unknown origin, combine that with the laptop and a computer monitor, then add back all the user interface you’d expect from an entertainment device.
The board shown in the first post of the thread is familiar to us. It seems to be based on the IgorPlug board which is a hack that goes waaaay back. This allows for the use of an IR media center remote and those input signals are easy to map to functions. The computer runs Windows Media Center which is already optimized for remote control but can use a wireless keyboard and mouse when more computer-centric functions are necessary.
With all on track the rest of the hack deals with hacking together a case. The laptop’s original body was ditched for some extended sides for the back of the monitor. [BoaSoft] did a great job of installing all the necessary ports in these extensions. Once in the kitchen everything is nice and neat and should stand the test of time.
Being curious by nature, [Marios] decided to see what kind of radio-frequency emissions may be generated by an Arduino connected to a simple breadboard wire, and more importantly try to pick them up using a RTLSDR dongle. Electromagnetic interferences are disturbances that affect electrical circuits due to either electromagnetic induction or electromagnetic radiation. Before going into the market, all electrical devices are thoroughly checked for unwanted electromagnetic emissions so they usually aren’t obvious suspects when such problems arise.
Using the Arduino embedded PWM controller in fast PWM mode and by manipulating the duty cycle, he actually managed to create a primitive form of amplitude modulation and was able to transfer a very simple audible signal at several frequencies up to 1.75GHz. Embedded after the break here is video of the system at work.
As a side note, did you know that during the solar storm of 1859 the EMI were so strong that the telegraph operators received several shocks? Pipelines maintenance systems also have to be aware of such events, that can lead sensors to provide inaccurate results.
Continue reading “Listening to Electromagnetic Interference with a RTLSDR Dongle”
[Benoit Frigon]’s builds are a tribute to tidiness: both his HTPC and media server are elegant creations packed full of features. He has quite the knack for clean builds in this form factor; his PBX server was met with high praise earlier this summer.
For the HTPC, [Benoit] gutted and cleaned an old DVR case and modified it to house a Mini-ITX board. He added standoff mounts to support the motherboard, then sketched up a template for the IO shield as a guide for cutting the back panel. The front of the DVR case originally had a 4-digit 7-segment display and a few simple buttons. Though he kept the original button layout, [Benoit] chose to replace the segment displays with a 20×2 character LCD. The new display is controlled via a python script on the HTPC, which runs an OpenElec Linux distro with XBMC 12.0.
The HTPC’s hard drive bay is a bit lighter these days, because [Benoit] decided to migrate his media storage to a separate server. Inside the new home media server is yet another Mini-ITX motherboard with an embedded Atom N2800 that runs Ubuntu Server. Live television streams via a WinTV HVR-2550 TV tuner and TVHeadend software. The case originally suspended the tuner from the IO bracket on the back (and nowhere else), which left the rest of the card dangerously unsupported inside. [Benoit] solved the problem by building an additional aluminum bracket that firmly holds both the PCIe riser and the tuner. Check out both builds’ pages for downloadable templates, software details and bill of materials.
In the market for a software defined radio? [Taylor Killian] wrote a comprehensive comparison of several models that are within the price range of amateurs and hobbyists.
You can get started with SDR using a $20 TV tuner card, but there’s a lot of limitations. These cards only work as receivers, are limited to a small chunk of the radio spectrum, and have limited bandwidth and sample rates. The new SDRs on the market, including the bladeRF, HackRF, and USRP offerings are purpose built for SDR experimentation. You might want an SDR to set up a cellular base station at Burning Man, scan Police and Fire radio channels, or to track ships.
[Taylor] breaks down the various specifications of each radio, and discusses the components used in each SDR in depth. In the end, the choice depends on what you want to do and how much you’re willing to spend. This breakdown should help you choose a hacker friendly SDR.
A few months ago, we saw a hack where a $20 USB TV tuner was transformed into a software-defined radio capable of reading GPS signals, listening to radio transmissions between aircraft and a control tower, and even a simple FM radio. This project is a perfect introduction to the RTL-SDR and Ham radio scene, but getting these projects up and running can be a bit overwhelming for anyone who hasn’t played around with this before. [Balint] is tackling this problem head on with a series of YouTube tutorials to get SDR noobs up and running with GNU Radio and the Realtec USB TV tuner.
To demonstrate the power of software-defined radio, [Balint] is using GNU Radio and the USB TV tuner that started it all, the Ezcap EZTV668 (conveniently back in stock at DealExtreme, but other options exist). Because software-defined radio is a touch confusing for a beginner to wrap their head around, [Balint] is beginning his tutorial series by explaining radio sources, sinks, and the GNU Radio interface.
Already, [Balint] has put up 5 tutorials and made the flowgraph files available in his gr-baz project. He’s doing a wonderful job opening up the software-defined radio scene to beginners, but he’s still looking for some feedback. If you have a suggestion on what [Balint] should cover next, leave a note in the YouTube comments and we’re sure [Balint] will get around to that eventually.
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”