DARPA Funds a $300 Software-Defined Radio For Hackers 94
Sparrowvsrevolution writes with this story from Forbes: "Over the weekend at the ToorCon hacker conference in San Diego, Michael Ossmann of Great Scott Gadgets revealed a beta version of the HackRF Jawbreaker, the latest model of the wireless Swiss-army knife tools known as 'software-defined radios.' Like any software-defined radio, the HackRF can shift between different frequencies as easily as a computer switches between applications–It can both read and transmit signals from 100 megahertz to 6 gigahertz, intercepting or reproducing frequencies used by everything from FM radios to police communications to garage door openers to WiFi and GSM to next-generation air traffic control system messages. At Ossmann's target price of $300, the versatile, open-source devices would cost less than half as much as currently existing software-defined radios with the same capabilities. And to fund the beta testing phase of HackRF, the Department of Defense research arm known as the Defense Advanced Research Projects Agency (DARPA) pitched in $200,000 last February as part of its Cyber Fast Track program."
Re:Antennas (Score:5, Informative)
Log periodic [wikipedia.org] or discone [wikipedia.org].
Re:Antennas (Score:5, Informative)
Antenna design for this must be miserable...
Anyone know if there is a good way to have relatively optimized reception over that whole spectrum without having to swap your antennas when changing frequencies?
- Toast
First post?
This appears to be an area of hot research. Ideas include switch band antennas [ittelkom.ac.id] and Software defined antennas [wikipedia.org].
This should be popular in the ham radio community (Score:5, Informative)
Software radios are becoming more popular in the amateur radio community. There are several manufacturers of very fine radios and quite a few build-it-yourself radios available too. I'll be watching this with great interest since one of the biggest problems with the lower-cost software radios is band coverage.
As Toast said a moment ago, antenna selection would be hard. Most radio amateurs would use an antenna tuner and/or a multiband antenna for the HF frequencies and an antenna switch for other bands of interest. I do just that. I have a 40 meter full wave horizontal loop antenna and use an antenna tuner and a 4:1 balun and can transmit on all bands from 40m through 10m and have very good results. It's also usable on 6m, but have never had a lot of luck with any kind of distant contacts.
Re:Antennas (Score:5, Informative)
I appreciate that. I might be heavily vested into computers, but radio isn't something I have had the pleasure to tinker with too much.
Also, found the repo / blog for that board (article was lacking in details):
http://www.greatscottgadgets.com/hackrf/ [greatscottgadgets.com]
https://github.com/mossmann/hackrf [github.com]
- Toast
Re:Antennas (Score:5, Informative)
You need an app that requires coverage from 100 MHz (why not down to 75 MHz for international FM broadcast band RX? Only need down to 87 or so in the USA..)
Usually wide band antenna design is not much of an issue in RF projects at the higher frequencies. Its pretty hard to make a dipole that covers the entire ham radio 3.5 to 4 mhz band than to cover a much smaller octave range at microwave bands.
Also "relatively optimized" is kinda non-specific. My antenna for 2M is optimized for clean pattern first and gain second and bandwidth a distant 3rd... I don't believe it can be used above 145 MHz or so. Which for my use is perfectly OK.
A "good" example of an antenna optimized for wide bandwidth would be an old fashioned VHF-lo thru UHF rooftop TV antenna. Miserable gain but crazy almost 10:1 frequency range.
Re:Most hackers use $30 TV tuners (Score:2, Informative)
They can't transmit though.
Re:Different HW Needed? (Score:5, Informative)
If you have SDR equipment that can operate on 2.4GHz and has enough bandwidth, you could operate WiFi, ZigBee, and other protocols at the same time. You could have WiFi on channel 1, ZigBee on 11, etc. As long as the chipping codes don't collide, you can go nuts. As an example of relatively simple SDRs, check out these Web SDRs [websdr.org]. These are single radios that digitize large swaths of spectrum. Each web user gets their own software virtual receiver that is tunable across the sampled spectrum. These radios can support hundreds of users at the same time, each listening to different freqs in different modes.
The radio hardware remains the same. The parts that can change are external to the actual 'radio' part - preselector filters, preamps, antennas, etc. Once you get the signal of interest to the radio, the processing is identical. Look around for descriptions of I/Q modulation - by supplying in-phase and quadrature signals, you can generate any modulation you want.
Re:Antennas (Score:5, Informative)
You're welcome. Amateur radio folk have been on the forefront of DSP and SDR development for many years now. If you want to fool around with digital signal processing but don't want to invest in hardware, you can use the GNURadio [gnuradio.org] package, along with the GNU Radio Companion to create DSP chains using an IDE and signals to/from your soundcard or arbitrary sound files.
For very little cash you can get a USB TV dongle that can be used as a signal source for GNU Radio. Search around a bit and you'll find sources - some are mentioned on the GNU Radio site.
If you're interested in doing DSP/SDR 'for real' over the air, consider getting a Technician-class Amateur radio license. You have all privileges above 30 MHz, and can do really nifty stuff. No Morse code required anymore - all theory and regs.
Another TOY SDR (Score:2, Informative)
Uses only 8 bit sampling which will severely limit the dynamic range. You might as well use one of the $30 RTL2832U/E4000 based TV tuners. DARPA throwing them $200,000 for the effort is a WASTE of taxpayer's money for these guys to build a 'TOY' SDR!