The Red Pitaya is a credit-card sized board that runs Linux, has Ethernet, and a good bit of RAM. This sounds a lot like a Raspberry Pi and BeagleBone Black, but the similarities end there. The Red Pitaya also has two RF inputs, two RF outputs, and a load of digital IOs, all connected to an Xilinx SoC that includes an FPGA. [Pavel] realized the Pitaya had all the components of a software-defined radio, and built an implementation to prove it.
The input for the SDR taps directly into one of the high impedance inputs with a simple loop antenna made out of telephone cable. The actual software-defined part of this radio borrows heavily from an Xilinx application note, while everything is controlled by either SDR# or HDSDR.
[Pavel] included a pre-built SD card image with all his software, so cloning this project is simply a matter of copying an SD card and building an antenna. The full source is also available, interesting if you would like to muck about with FPGAs and SDRs.
Hackers everywhere are having a lot of fun with SDR – as is obvious from the amount of related posts here on Hackaday. And why not, the hardware is cheap and easily available. There are all kinds of software tools you can use to dig in and explore, such as SDR# , Audacity, HDSDR and so on. [illias] has been following SDR projects for a while, which piqued his interest enough for him to start playing with it. He didn’t have any real project in mind so he focused on studying the methodology and the tools available for analyzing 433MHz RF transmission. He describes the process of using MATLAB to recover the transmissions being received by the SDR
He started off by studying the existing tools available to uncover the details of the protocol. The test rig uses an Arduino UNO with the rc-switch library to transmit via a common and inexpensive 433MHz module. SDR# is used to record the transmissions and Audacity allows [illias] to visualize the resulting .wav files. But the really interesting part is where he documents the signal analysis using MATLAB.
He used the RTL-SDR package in conjunction with the Communications System Toolbox to perform spectrum analysis, noise filtering and envelope extraction. MATLAB may not be the easiest to work with, nor the cheapest, but its powerful features and the fact that it can easily read data coming from the SDR makes it an interesting tool. For the full skinny on what this SDR thing is all about, check out Why you should care about Software Defined Radio.
It hasn’t become a household term yet, but Software-Defined Radio (SDR) is a major player on the developing technology front. Whether you’re building products for mass consumption, or just playing around for fun, SDR is worth knowing something about and I’ll prove it to you.
Continue reading “Why You Should Care About Software Defined Radio”
[Rich, VE3MKC] has made a lot of progress on his Software Defined Radio (SDR) which is based on a Teensy. His latest update shows off the hardware in an enclosure and a few new features.
When we looked at this in April of last year it was pretty much a proof-of-concept with components hanging loose from jumper wires. The new case mounts everything securely in a plastic Hammond enclosure with copper clad for the front and rear panels. The SoftRock SDR unit was yanked from its case and retrofitted with connectors to make it swappable for other units.
A little help goes a long way and [Rich] thanks his friend [Loftur, VE2LJX] for contributing numerous code improvements and feature additions which can be viewed in the repository. Check out the video below where these features are shown off.
In its present state the radio draws 80 mA at 12V in receive mode. It doesn’t transmit yet but we’ll keep our eyes open for another update on that. [Rich] plans to populate the input circuitry and write the transmit code next.
Continue reading “Casing up the Teensy SDR”
Last year’s Hackaday Prize saw a lot of projects that were crying out to be Kickstarter Campaigns, but non has seen people throwing money at their screens quite like [Michael]’s PortableSDR. It’s a small, handheld, battery-powered shortwave software defined transceiver that can do just about everything with coverage up to 30MHz. It’s the ultimate apocalypse radio, a contender for to the throne now held by the ‘my first radio’ Baofeng, and now, finally, a campaign on Kickstarter.
The PortableSDR (now called the PSDR) started off as [Michael]’s ideal radio. It just so happened the Hackaday Prize gave him the impetus design, develop, and build the radio that would eventually land him third place in The Hackaday Prize.
The radio itself is completely self-contained and battery-powered, implementing a software defined radio on an STM32F4 processor. The design includes an LCD for the waterfall display, vector network analysis, and the ability to receive GPS.
In keeping with its ham heritage, [Michael] is offering the PSDR as a kit, with a PCB, enclosure, and all the parts you can’t get on Digikey available for a $250 pledge. Get those toaster reflow ovens warm, because there’s a lot of SMD parts in this build.
Continue reading “PortableSDR Makes It To Kickstarter”
[Texane] built a low-cost software defined radio rig which could be remotely controlled. This allows the hardware to be placed outside for better reception, while being controlled from any PC that can connect over TCP. To do this, he created a fork of librtlsdr, the library used to turn cheap TV tuners into software defined radios.
The official release of rtl-sdr includes the rtl_tcp utility, which is meant for this purpose. Unfortunately, not all of the SDR tools for Linux support this. By modifying the library itself, remote devices interact with software in the same way as local devices. This means that any software that supports librtlsdr should work.
The outdoor rig contains a BeagleBone Black and the SDR hardware, sealed up in a weather-resistant box. This connects to [Texane]’s home network over ethernet, and allows SDR utilities to be run elsewhere.
This feature is quite experimental, but the source for the fork is provided for those who want to build the code and try it out.
For anyone getting into the world of Software Defined Radio, the first purchase should be an RTL-SDR TV tuner. With a cheap, $20 USB TV tuner, you can listen to just about anything between 50 and 1750 MHz. You can’t send, the sample rate isn’t that great, but this USB dongle gives you everything you need to begin your explorations of the radio spectrum.
Your second Software Defined Radio purchase is a matter of contention. There are a lot of options out there for expanding a rig, and the HackRF is a serious contender to expand an SDR rig. You get 10 MHz to 6 Gigahertz operating frequency, 20 million samples per second, and the ability to transmit. You have your license, right?
Unfortunately the HackRF is a little expensive and is unavailable everywhere. [Gareth] is leading the charge and producing the HackRF Blue, a cost-reduced version of the HackRF designed by [Michael Ossmann].
The HackRF Blue’s feature set is virtually identical, and the RF performance is basically the same: both the Blue and the HackRF One can get data from 125kHz RFID cards. All software and firmware is interchangeable. If you were waiting on another run of the HackRF, here ‘ya go.
[Gareth] and the HackRF Blue team are doing something rather interesting with their crowdfunding campaign: they’re giving away Blues to underprivileged hackerspaces, with hackerspaces from Togo, Bosnia, Iran, India, and Detroit slated to get a HackRF Blue if the campaign succeeds.
Thanks [Praetorian] and [Brendan] for sending this in.
Continue reading “HackRF Blue”