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.
Taking inspiration from our own [Gregory L. Charvat], whose many radar projects have graced our pages before, [Luigi Freitas]’ 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”
If you’re tired of underhanded deals going down behind closed doors maybe you need to start carrying around this transparency grenade. The enclosure is modeled after a Soviet-era F1 Hand Grenade. But it’s not filled with explosives and won’t send deadly shrapnel around the room. Instead, when the pin is pulled it starts recording audio and sniffing network packets, then broadcasts both to a remote server. Perhaps you could consider this to be data shrapnel sent around the world.
The exploded parts image above shows what hardware is at use. There’s a Gumstix board at the heart of the device which uses a WiFi module for sniffing and broadcasting data. The LED bar graph which you see in the fully assembled unit shows the wireless signal strength.
It sounds like the enclosure itself was 3D printed from Tusk2700T translucent resin but we’re a little confused by this part of the hardware description. We don’t have much of a need to transmit recordings of our meetings, but we’d love to use this case design for that MP3 enclosure.
Maybe $15K for an elaborate balancing telepresence robot is a bit out of one’s league. In that case, another Bay Area Maker Faire exhibitor — Wild Planet — has you covered. Faire attendees got a hands-on sneak preview of the upcoming Spy Video TRAKR, a video-transmitting radio-controlled toy that’s programmable and extensively hackable.
The TRAKR has an impressive pedigree. It’s a collaborative effort between three successful and creative technology companies: Wild Planet, makers of the Spy Gear toy line; MOTO Development Group, designers of the Flip Video camera; and Making Things, software designers for the Make Controller.
So just how hackable are we talking? The Spy Video TRAKR is intended right out of the box to use downloadable apps, and allows development of new programs in C. The controller and vehicle each contain their own ARM9 processor, and the ’bot features 8 megs of RAM, an SD card slot and USB client and host (yes, host) ports. And that’s all with the cover still on. Pop the lid, and you’ll find links to online schematics and neatly-labeled breakout headers for deeper exploration.
The Spy Video TRAKR is expected to ship in October with a target price of $139 or less. Additional photos after the break.
Continue reading “BAMF2010: Spy TRAKR – no lasers, $14,861 cheaper”