SDR Sniffing Electric Gates

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. The final implementation was done around an Onion Omega which talks directly to the RF transmitter module using the fast-gpio binary. Internet connectivity was achieved using Onion Cloud API which is used to trigger the execution of code thereby sending the gate opening signal.

[Gilad Fride] uses the IFTTT Do button to provide a GUI and he demonstrates this in action using an iPhone in the video below. The project can be extended to open garage doors or turn off the lights of your room over the internet.

If you are looking to hack your home security system, look no further as SDRs have be used to communicate with wireless products effectively in the past. We are hoping manufacturers take a hint and start using better encryption.  Continue reading “SDR Sniffing Electric Gates”

Scanning Electron Microscope Adds To Already Impressive Garage Lab

When you’re a high schooler who built a semiconductor fab in your garage, what’s next on your agenda? Why, adding a scanning electron microscope to your lab, naturally. How silly of you to ask.

When last we stumbled across the goings on in the most interesting garage in New Jersey, [Sam Zeloof] was giving a tour of his DIY semiconductor fabrication lab and showing off some of the devices he’s made there, including diodes and MOSFETs. As impressive as those components are, it’s the equipment he’s accumulated that really takes our breath away. So adding an eBay SEM to the mix only seems a natural progression, and a good reason to use some of the high vacuum gear he has. The video below shows [Sam] giving a tour of the 1990s-vintage instrument and shows images of various copper-sputtered samples, including a tick, which is apparently the state bird of New Jersey.

SEM hacks are by no means common around here, but they’re not unheard of. [Ben Krasnow] has used his to image cutting tools and phonograph records in action, and there are a few homebrew SEMs kicking around too. But our hats are off to [Sam] for yet another acquisition and a great tutorial to boot.

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3D Printed Radiation Patterns

Radiation patterns for antennas can be utterly confusing, especially when presented in two dimensions, as they usually are. Fear not, [Hunter] has your back with 3D printed and color-coded radiation patterns.

In the field of antenna design, radiation patterns denote the relationship between the relative strength of radio waves emitted from antennas and the position of a receiver/transmitter in 3D space. In practice, probes can be used to transmit/receive from documented locations around an antenna while recording signal intensity, allowing researchers and engineers to determine the characteristics of arcane antennas. These measurements are normally expressed as two-dimensional slices of three-dimensional planes. Naturally, this sometimes (often) complex geometry is difficult for all but the most spatially inclined to mentally conceptualize with only the assistance of a 2D drawing. With computers came 3D models, but [Hunter] wasn’t satisfied with a model on a screen: they wanted something they could hold in their hands.

To that end, [Hunter] simulated several different antenna structures, cleaned up the models for 3D printing, and 3D printed them in color sandstone, and the end result is beautiful. By printing in colored sandstone through Shapeways, [Hunter] now has roughly walnut-sized color-coded radiation patterns they can hold in their hand. To save others the work, [Hunter] has posted his designs on Shapeways at Ye Olde Engineering Shoppe. So far, he has a horn antenna, dipole, inset fed patch antenna and a higher order mode of a patch antenna, all of which are under 15.00USD. Don’t see the antenna radiation pattern of your dreams? Fret not, [Hunter] is looking for requests, so post your ideas down in the comments!

Further, beyond the immediate cool factor, we can see many legitimate uses for [Hunter’s] models, especially in education. With more and more research promoting structural rather than procedural learning, [Hunter’s] designs could easily become a pedagogical mainstay of antenna theory classes in the future. [Hunter] is not the only one making the invisible visible, [Charles] is mapping WiFi signals in three dimensions.

Video after the break.

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The Internet Of Interactive Cats

[Tuco] is a cat who shares the space of [Micah Elizabeth Scott]. He is a large tabby tomcat, and he is polydactyl, which is to say he has a congenital excess of toes. He is an extremely active and engaging creature and enjoys playing and interacting with her. We covet [Tuco].

Sadly for the rest of us who love cats, of course, unless we know [Micah] personally we’ll never have the opportunity to play with [Tuco]. She appreciates the cat-shaped void that will leave in our lives, and to help us she’s building a telepresence robot to allow the rest of us to interact with him in real time.

Her idea is to make a flying robot equipped with a camera on a gimbal, and because to mounting it on a multirotor platform would be a hazard, instead she’s making something closer to the aerial cameras you might be familiar with from sporting fixtures, a motorised platform suspended from the corners of her roof space on a set of nylon ropes, that can move at will by adjusting the length of each tether. It is suggested that one day the device will be able to launch plastic bolts for [Tuco] to chase and to incorporate other interactive features to allow online users to engage with him.

We are shown progress so far in the video introducing the project that we’ve placed below the break, she has completed a prototype windlass mechanism and worked on reverse engineering the gimbal mechanism for serial control. We’ll probably never meet [Tuco] in person, but we can’t wait to interact with him online.

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Quality Assurance Through FPGA

[Claire Chen] and [Mark Zhao], students in [Bruce Land]’s ECE5760 class at Cornell, created a project aimed at the manufacturing sector: quality-checking manufactured products automatically by visually scanning a bunch of them and processing the pixels one at a time. Ordinarily, the time when the widget comes off the line is when you have to bring in actual people to inspect. This project uses morphological image processing to like dilation and erosion to look for flaws.

[Claire] and [Mark] created a simulated manufacturing line with a servo-driven belt that brings a series of Spree candies into the range of a camera, which scans them. The SoC with a Cyclone V FPGA and ARM Cortex-9 then processes the raw images to establish the object’s color, while running it through a couple of algorithms to look for defects. The FPGA tracks how many Sprees that have passed by as well as their color, maintaining a 99% success rate with a rate of 5-10 frames per second. The FPGA also looks at each blob of color as a collection of pixels, establishing connectivity to help to distinguish multiple Sprees touching each other.

Also be sure to check out [Claire] and [Mark]’s bike sonar project from a previous semester.

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Drop-in Controller For EBay K40 Laser Engraver Gets Results

[Paul de Groot] wrote in to let us know about a drop-in controller replacement he designed for those economical K40 laser engravers that are everywhere on eBay. With the replacement controller, greatly improved engraving results are possible along with a simplified toolchain. Trade in the proprietary software and that clunky security dongle for Inkscape and a couple of plugins! [Paul] felt that the work he accomplished was too good to keep to himself, and is considering a small production run.

Laser engravers are in many ways not particularly complex devices; a motion controller moves the head in x and y, and the laser is turned on or off when needed. But of course, the devil is in the details and there can be a surprising amount of stuff between having a design on your screen and getting it cut or engraved in the machine. Designing in Inkscape, exporting to DXF, importing the DXF to proprietary software (which requires a USB security dongle to run), cleaning up any DXF import glitches, then finally cutting the job isn’t unusual. And engraving an image with varying shades and complex dithering? The hardware may be capable, but the stock software and controller? Not so much. It’s easy to see why projects to replace the proprietary controllers and software with open-source solutions have grown.

Cheap laser engravers may come with proprietary controllers and software, but they don’t need to stay that way. Other efforts we have seen in this area include LaserWeb, which provides a browser-based interface to a variety of open-source motion controllers like Grbl or Smoothieware. And if you’re considering a laser engraver, take a few minutes to learn from the mistakes of other people.

Hackaday Prize Entry: Earthquake Warnings Via Tweets

Seismic waves travel through the Earth’s crust at about four kilometers a second. Light travels through fiber at about 200,000 kilometers per second. Taking network lag into account, it’s possible to read a Tweet about an earthquake a few seconds before the shaking starts. This is the concept behind an XKCD strip and a project for the Hackaday Prize.

[Zalmotek]’s Earthquake Validation Gadget is an Internet-connected box designed for those few seconds between asking yourself, ‘is this an earthquake’ and saying, ‘yeah, this is totally an earthquake’. Inside this wall-mounted box is both a sensitive vibration sensor and a microcontroller connected to the Internet. If the vibration sensor goes off, it checks the Internet — the USGS website is a great start, by the way — for any large, local earthquakes. If there’s a possibility that shaking is an earthquake, lights and sirens go off, telling you to take cover.

The idea of an ‘earthquake warning device’ isn’t new. The USGS has a system in place for just this sort of thing. It’s good to see independent researchers working on this, though, and it makes for a great entry to the Hackaday Prize.