Category Archives: sdr

CPLD-Based Synchronization of Multiple Software Defined Radios

Posted on by

Forgive the click bait headline, but the latest work from [Marco Bartolucci] and [José A. del Peral-Rosado] is really great. They’re using multiple HackRFs, synchronized together, with hybrid positioning algorithms to derive more precise localization accuracy. (PDF)

Like all SDRs, the HackRF can be used to solve positioning problems using WIFi, Bluetooth, 3G, 4G, and GNSS. Multiple receivers can also be used, but this requires synchronization for time-based or frequency-based ranging. [Bartolucci] and [Peral-Rosado] present a novel solution for synchronizing these HackRFs using a few convenient ports available on the board, a bit of CPLD hacking, and a GNSS receiver …read more

Continue reading CPLD-Based Synchronization of Multiple Software Defined Radios→

SDR Sniffing Electric Gates

Posted on by

Most wireless OEM hardware traditionally use 433MHz OOK modules to exchange information. The encoding and encryption of this data stream is left as a task for the embedded software designer. In most cases, the system can be hacked using a replay attack where an RF packet is recorded and replayed to emulate a valid user. [Gilad Fride] hacked his parking gate using this technique but decided to go the extra mile of connecting it to the internet.

He used an RTL-SDR dongle and ook-decoder by [jimstudt] to sniff out the gate code and this code was tested using an Arduino. …read more

Continue reading SDR Sniffing Electric Gates→

Exposing Dinosaur Phone Insecurity With Software Defined Radio

Posted on by

Long before everyone had a smartphone or two, the implementation of a telephone was much stranger than today. Most telephones had real, physical buttons. Even more bizarrely, these phones were connected to other phones through physical wires. Weird, right? These were called “landlines”, a technology that shuffled off this mortal coil three or four years ago.

It gets even more bizarre. some phones were wireless — just like your smartphone — but they couldn’t get a signal more than a few hundred feet away from your house for some reason. These were ‘cordless telephones’. [Corrosive] has been working on …read more

Continue reading Exposing Dinosaur Phone Insecurity With Software Defined Radio→

If The I And Q Of Software Defined Radio Are Your Nemesis, Read On

Posted on by

For those of us whose interests lie in radio, encountering our first software defined radio must have universally seemed like a miracle. Here is a surprisingly simple device, essentially a clever mixer and a set of analogue-to-digital or digital-to-analogue converters, that can import all the complex and tricky-to-set-up parts of a traditional radio to a computer, in which all signal procession can be done using software.

When your curiosity gets the better of you and you start to peer into the workings of a software defined radio though, you encounter something you won’t have seen before in a traditional radio. …read more

Continue reading If The I And Q Of Software Defined Radio Are Your Nemesis, Read On→

If The I And Q Of Software Defined Radio Are Your Nemesis, Read On

Posted on by

For those of us whose interests lie in radio, encountering our first software defined radio must have universally seemed like a miracle. Here is a surprisingly simple device, essentially a clever mixer and a set of analogue-to-digital or digital-to-analogue converters, that can import all the complex and tricky-to-set-up parts of a traditional radio to a computer, in which all signal procession can be done using software.

When your curiosity gets the better of you and you start to peer into the workings of a software defined radio though, you encounter something you won’t have seen before in a traditional radio. …read more

Continue reading If The I And Q Of Software Defined Radio Are Your Nemesis, Read On→

A Full Stack GPS Receiver

Posted on by

The usual way of adding GPS capabilities to a project is grabbing an off-the-shelf GPS module, plugging it into a UART, and reading the stream of NEMA sentences coming out of a serial port. Depending on how much you spend on a GPS module, this is fine: the best modules out there start up quickly, and a lot of them recognize the logical AND in ITAR regulations.

For [Mike], grabbing an off-the-shelf module is out of the question. He’s building his own GPS receiver from the ground up using a bit of hardware and FPGA hacking. Already he’s getting good …read more

Continue reading A Full Stack GPS Receiver→

See Satellites with a Simple Radio Telescope

Posted on by

Have you got a spare Dish Network antenna lying about? They’re not too hard to come by, either curbside on bulk waste day or perhaps even on Freecycle. If you can lay hands on one, you might want to try this fun radio telescope build.

Now, don’t expect much from [Justin]’s minimalist build. After all, you’ll be starting with a rather small dish and an LNB for the Ku band, so you won’t be doing serious radio astronomy. In fact, the BOM doesn’t include a fancy receiver  – just a hacked satellite finder. The idea is to just get a …read more

Continue reading See Satellites with a Simple Radio Telescope→

Backscatter Your Own FM Pirate Radio Station

Posted on by

If you live in a city, you’re constantly swimming in a thick soup of radio-frequency energy. FM radio stations put out hundreds of kilowatts each into the air. Students at the University of Washington, [Anran Wang] and [Vikram Iyer], asked themselves if they could harness this background radiation to transmit their own FM radio station, if only locally. The answer was an amazing yes.

The trailer video, embedded below, demos a couple of potential applications, but the paper (PDF) has more detail for the interested. Basically, they turn on and off an absorbing antenna at a frequency that’s picked so …read more

Continue reading Backscatter Your Own FM Pirate Radio Station→

Using SDR to Take Control of Your Home Security System

Posted on by

[Dan Englender] was working on implementing a home automation and security system, and while his house was teeming with sensors, they used a proprietary protocol which was not supported by the open source system he was trying to implement. The problem with home automation and security systems is the lack of standardization – or rather, the large number of (often incompatible) standards used to ensure consumers get tied in to one specific system. He has shared the result of his efforts at getting the two to talk to each other via his project decode345.

The result enabled him to receive …read more

Continue reading Using SDR to Take Control of Your Home Security System→

Using SDR to Take Control of Your Home Security System

Posted on by

[Dan Englender] was working on implementing a home automation and security system, and while his house was teeming with sensors, they used a proprietary protocol which was not supported by the open source system he was trying to implement. The problem with home automation and security systems is the lack of standardization – or rather, the large number of (often incompatible) standards used to ensure consumers get tied in to one specific system. He has shared the result of his efforts at getting the two to talk to each other via his project decode345.

The result enabled him to receive …read more

Continue reading Using SDR to Take Control of Your Home Security System→