Putting That Airplane On The Map – Live And With Python

December 3, 2018 by Sven Gregori 9 Comments

Mankind’s fascination with airplanes is unbroken. Whether you’re outside with your camera, getting an actual glimpse of the aircraft, or sitting at home with your RTL-SDR dongle and have a look at them from a distance, tracking them is a fun pastime activity. Provided, of course, that you are living close by an airport or in an area with high enough air traffic. If not, well there’s always real-time tracking online to fall back to, and as [geomatics] will show you, you can build your own live flight tracking system with a few lines of Python.

As it’s usually the case with Python, a lot of functionality is implemented and readily available from external modules, which lets you focus on the actual application without having to worry too much about the details. Similarly, plenty of data can be requested from all sorts of publicly accessible APIs nowadays. If you are looking for a simple-enough example to get into both subjects with a real-world application, [geomatics]’ flight tracker uses cartopy to create a map using Open Street Map data, and retrieves the flight information from ADS-B Exchange‘s public API.

We have seen ADS-B Exchange mentioned a few times before, for example with this ESP8266 based plane spotter and its successor. And if you’re more curious about the air traffic in your direct surroundings, it’s probably time for a DVB USB dongle.

SDR Is At The Heart Of This Soup-Can Doppler Radar Set

November 29, 2018 by Dan Maloney 6 Comments

Want to explore the world of radar but feel daunted by the mysteries of radio frequency electronics? Be daunted no more and abstract the RF complexities away with this tutorial on software-defined radar by [Luigi Cruz].

Taking inspiration from our own [Gregory L. Charvat], whose many radar projects have graced our pages before, this plunge into radar is spare on the budgetary side but rich in learning opportunities. The front end of the radar set is almost entirely contained in a LimeSDR Mini, a software-defined radio that can both transmit and receive. The only additional components are a pair of soup can antennas and a cheap LNA for the receive side. The rest of the system runs on GNU Radio Companion running on a Raspberry Pi; the whole thing is powered by a USB battery pack and lives in a plastic tote. [Luigi] has the radar set up for the 2.4-GHz ISM band, and the video below shows it being calibrated with vehicles passing by at known speeds.

True, the LimeSDR isn’t exactly cheap, but it does a lot for the price and lowers a major barrier to getting into the radar field. And [Luigi] did a great job of documenting his work and making his code available, which will help too. Continue reading “SDR Is At The Heart Of This Soup-Can Doppler Radar Set” →

Sniffing RFID Readers With A Piece Of Paper

November 28, 2018 by Tom Nardi 17 Comments

We feature plenty of printed projects here on Hackaday, though they tend to be of the three dimensional type thanks to the proliferation of affordable 3D printers. But in this case, [Milosch Meriac] has managed to put together a printable design that’s not only a very cool hack, but is made up of a scant two dimensions. His creation, which could perhaps be considered something of an interactive circuit diagram, allows anyone with a paper printer and a few passive components to make a functional low-frequency RFID sniffer.

[Milosch] tells us the goal of the project is to lower the barrier for experimenting with the RFID technology that’s increasingly part of our everyday lives. Rather than having to use something expensive and complicated such as an oscilloscope, experimenters can simply plug their DIY RFID sniffer into their computer’s line-in jack and explore the produced waveform with open source tools.

To create a paper RFID sniffer, you start by printing the image out on a thick piece of paper, like card stock. You then apply foil tape where indicated to serve as traces in this makeshift PCB, and start soldering on the components as described in the text. [Milosch] says the assembly procedure is so simple even a kid can do it, and the total cost of each assembled sniffer is literally pennies; making this an excellent project for schools or really any large group.

If you want to play it safe the sniffer can be connected to a USB sound card rather than your machine’s primary sound hardware, and still come in dirt cheap. [Milosch] stops short of explaining the software side of things in this particular project, but any tool which can use input from the sound card as a makeshift oscilloscope should be a good start.

In the past we’ve seen [Milosch] perform low frequency RFID sniffing through the sound card with the powerful baudline tool, but if you want a little more capable hardware, we can point you in the right direction.

A Sneak Peek At Anechoic Chamber Testing

November 17, 2018 by Tom Nardi 23 Comments

[Mathieu Stephan] has something new in the works, and while he isn’t ready to take the wraps off of it yet, he was kind enough to document his experience putting the mysterious new gadget through its paces inside an anechoic chamber. Considering the majority of us will never get inside of one of these rooms, much less have the opportunity to test our own hardware in one, he figured it was the least he could do.

If you’re not familiar with an anechoic chamber, don’t feel bad. It’s not exactly the sort of thing you’ll have at the local makerspace. Put simply it’s a room designed to not only to remove echos on the inside, but also be completely isolated from the outside. But we aren’t just talking about sound deadening, the principle can also be adapted to work for electromagnetic waves. So not only is in the inside of the anechoic chamber audibly silent, it can also be radio silent.

This is important if you want to test the performance of things like antennas, as it allows you to remove outside interference. As [Mathieu] explains, both the receiver and transmitter can be placed in the chamber and connected to a vector network analyzer (VNA). The device is able to quantify how much energy is being transferred between the two devices, but the results will only be accurate if that’s the only thing the VNA sees on its input port.

[Mathieu] can’t reveal images of the hardware or the results of the analysis because that would give too much away at this point, but he does provide the cleverly edited video after the break as well as some generic information on antenna analysis and the type of results one receives from this sort of testing. Our very own [Jenny List] has a bit more information on the subject if you’d like to continue to live vicariously through the accounts of others. For the rest of us, we’ll just have to settle for some chicken wire and a wooden crate.

Continue reading “A Sneak Peek At Anechoic Chamber Testing” →

All The Goodies You Need For Your RTL-SDR

November 9, 2018 by Jenny List 14 Comments

When the RTL2832-based USB digital TV sticks were revealed to have hidden capabilities that made the an exceptionally cheap software-defined radio receiver, it was nothing short of a game-changing moment for the home radio experimenter. The RTL might not be the best radio available, but remains a pretty good deal for only $10 from your favourite online supplier.

Having bought your RTL SDR, you will soon find yourself needing a few accessories. A decent antenna perhaps, an HF upconverter, and maybe an attenuator. To help you, [IgrikXD] has come up with a repository containing open-source implementations of all those projects and more. There’s an HF upconverter handily in both SMD and through-hole versions, as well as a wideband active antenna. A resonant antenna for a single band will always out-perfom a wideband device if your interest lies on only one frequency, but when your receiver has such a wide range as that of the RTL it’s irresistible to look further afield so the wideband antenna is a useful choice.

The RTL SDR is a device that just keeps on giving, and has featured innumerable times here since since its first appearance a few years ago. Whether you are into passive radar or using it to decode data from RF-equipped devices it’s the unit of choice, though we rather like it as a piece of inexpensive test equipment.

Via Hacker News.

Header image: Joeceads [CC BY-SA 4.0].

Revive That Old Analog Cell Phone With SDR

November 3, 2018 by Tom Nardi 32 Comments

With the latest and greatest 5G cellular networks right around the corner, it can be difficult to believe that it wasn’t so long ago that cell phones relied on analog networks. They aren’t used anymore, but it might only take a visit to a swap meet or flea market to get your hands on some of this vintage hardware. Of course these phones of a bygone era aren’t just impractical due to their monstrous size compared to modern gear, but because analog cell networks have long since gone the way of the floppy disk.

But thanks to the efforts of [Andreas Eversberg] those antique cell phones may live again, even if it’s only within the radius of your local hackerspace. His software allows the user to create a functioning analog base station for several retro phone networks used in Europe and the United States, such as AMPS, TACS, NMT, Radiocom, and C450. You can go the old school route and do it with sound cards and physical radios, or you can fully embrace the 21st century and do it all through a Software Defined Radio (SDR); in either event, calls to the base station and even between multiple mobile devices is possible with relatively inexpensive hardware.

[Andreas] has put together exceptional documentation for this project, which starts with a walk through on how you can setup your DIY cell “tower” with traditional radios. He explains that amateur radios are a viable option for most of the frequencies used, and that he had early success with modifying second-hand taxi radios. He even mentions that the popular BaoFeng handheld radios can be used in a pinch, though not all the protocols will work due to distortion in the radio.

If you want to take the easy way out, [Andreas] also explains how to replace the radios with a single SDR device. This greatly simplifies the installation, and turns a whole bench full of radios and wires into something you can carry around in your pack if you were so inclined. His software has specific options to use the LimeSDR and LimeSDR-Mini, but you should be able to use other devices with a bit of experimentation.

We’ve previously reviewed the LimeSDR-Mini hardware, as well as covered its use in setting up DIY GSM networks.

FT8: Saving Ham Radio Or Killing It?

November 2, 2018 by Al Williams 179 Comments

It is popular to blame new technology for killing things. The Internet killed newspapers. Video killed the radio star. Is FT8, a new digital technology, poised to kill off ham radio? The community seems evenly divided. In an online poll, 52% of people responding says FT8 is damaging ham radio. But ham operator [K5SDR] has an excellent blog post about how he thinks FT8 is going to save ham radio instead.

If you already have an opinion, you have probably already raced down to the comments to share your thoughts. I’ll be honest, I think what we are seeing is a transformation of ham radio and like most transformations, it is probably both killing parts of ham radio and saving others. But if you are still here, let’s talk a little bit about what’s going on in ham radio right now and how it relates to the FT8 question. Oddly enough, our story starts with the strange lack of sunspots that we’ve been experiencing lately. Continue reading “FT8: Saving Ham Radio Or Killing It?” →