Since the ether is an old term for the fictitious space where radio waves propagate, we always thought it was strange that the term ethernet refers to wired communication. Sure, there are wireless devices, but that’s not really ethernet. [Jacek] had the same thought, but decided to do something about it.
What he did is use two different techniques to alter the electromagnetic emission from an ethernet adapter on a Raspberry Pi. The different conditions send Morse code that you can receive at 125 MHz with a suitable receiver.
Practical? Hardly, unless you are looking to exfiltrate data from an air-gapped machine, perhaps. But it does have a certain cool factor. The first method switches the adapter between 10 Mbps and 100 Mbps. The second technique uses a stream of data to accomplish the modulation. The switching method had a range of around 100 meters while the data-based method topped out at about 30 meters. The code is on GitHub if you want to replicate the experiment.
There is plenty of precedent for this sort of thing. In 1976 Dr. Dobb’s Journal published an article about playing music on an Altair 8800 by running code while an AM radio was nearby. We’ve seen VGA adapters forced to transmit data, too.
Continue reading “Ethernet Goes To The Ether”
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”
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”