Wireless Hacks

WiFi Controlled Plane Is Cheap Flying Fun

April 12, 2019 by 15 Comments

The world of radio controlled aircraft used to be an expensive and exclusive hobby, limited to those with the time and money to invest in difficult builds and pricey radio gear. More recently, the hobby has become more accessible, with cheap ready to fly planes available that can be flown in smaller spaces like suburban parks. [Ravi Butani] has built just such a plane, and you can even fly it with your smartphone!

An ESP8266 does double duty here as both the brains and the communication system. A custom smartphone app communicates with the plane over WiFi. Touching the screen increases the throttle, while steering is achieved through tilting the phone. There’s also monitoring of signal strength and battery level, with the phone vibrating if the plane is getting out of range or low on battery.

Flight control is via differential thrust, with power coming courtesy of two small DC motors controlled by tiny SMD MOSFETs. The plane flies remarkably well in still conditions, and the WiFi connection is stable in an open park environment. [Ravi] reports that control is possible at a range of around 70 meters using a Motorola G5S smartphone.

Despite the simplicity of the build and the low cost of the components, the final product performs admirably. It would be a great weekend project, and at the end of it, you get to go and fly your new plane! If you’re worried about keeping your batteries charged, don’t worry – there’s a solution for that. Video after the break.

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Transcending the Stack with the Right Network Protocol

April 9, 2019 by 14 Comments

The increase in network-connected devices the past years has been something of a dual-edged sword. While on one hand it’s really nice to have an easy and straight-forward method to have devices talk with each other, this also comes with a whole host of complications, mostly related to reliability and security.

With WiFi, integrating new devices into the network is much trickier than with Ethernet or CAN, and security (e.g. WPA and TLS) isn’t optional any more, because physical access to the network fabric can no longer be restricted. Add to this reliability issues due to interference from nearby competing WiFi networks and other sources of electromagnetic noise, and things get fairly complicated already before considering which top-layer communication protocol one should use. Continue reading “Transcending the Stack with the Right Network Protocol” →

Duck And Cover With This WiFi “Geiger Counter”

April 8, 2019 by 9 Comments

There’s perhaps no sound more recognizable than the frantic clicking of a Geiger counter. Not because this is some post-apocalyptic world in which everyone is personally acquainted with the operation of said devices, but because it’s such a common effect used in many movies, TV shows, and video games. If somebody hears that noise, even if it doesn’t really make sense in context, they know things are about to get serious.

Capitalizing on this phenomena, [Anton Haidai] has put together a quick hack which turns the ESP8266 into a “Geiger counter” for WiFi. Rather than detecting radiation, the gadget picks up on the strongest nearby WiFi signal and will start clicking in response to signal strength. As the signal gets stronger, so does the clicking. While primarily a novelty, it’s an interesting idea that could potentially be useful for things like fox hunting.

The hardware is really about as simple as it gets, just a basic buzzer attached to one of the digital pins on a NodeMCU development board. This project is more of a proof of concept, but if it were to be developed further it would be interesting to see the electronics placed into a 3D printed replica of one of the old Civil Defense Geiger counters. Perhaps even integrating an analog gauge that can bounce around in response to signal strength.

Software-wise there is the option of locking onto one single network SSID or allowing the device to find the strongest network in the area. Even if you’re not in the market for a chirping WiFi detector, the code is a good example of how you can detect signal RSSI and act on it accordingly; a neat trick which might come in handy in a future project.

If you’re more interested in the real thing, we’ve got plenty of DIY Geiger counters in the archive for you to check out. From diminutive builds that can be mounted to the top of a 9V battery to high-tech solid state versions with touch screen interfaces, you should have plenty of inspiration if you’re looking to kit yourself out before your next drive through the Chernobyl Exclusion Zone.

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Pocket-Sized Deauther Could Definitely Get You In Trouble

April 4, 2019 by 40 Comments

Interfering with radio communications, whether through jamming, deauthing attacks, or other meddling, is generally considered a crime, and one that attracts significant penalties. However, studying such techniques should provide a useful edge in the electronic wars to come. In this vein, [Giorgio Filardi] has recently built a WiFi deauther the size of a credit card.

The device has a simple interface, consisting of 3 buttons and a small OLED screen. It can also be accessed remotely and controlled through a web interface. A NodeMCU ESP8266 board runs the show, using [spacehuhn]’s deauther firmware. The point-to-point construction probably won’t hold up to much rough and tumble out in the field, but it’s fine for a bench test. We’d recommend constructing an enclosure if it was to be used more regularly.

There’s plenty of functionality baked in – the device can scan for networks, perform deauth attacks, and even create spoof networks. It’s a tricky little device that serves to highlight several flaws in WiFi security that are yet to be fixed by the powers that be.

Using one of these devices for nefarious purposes will likely get you into trouble. Experimenting on your own networks can be educational, however, and goes to show that wireless networks are never quite as safe as we want them to be.

If you’re wondering as to the difference between deauthentication and jamming, here’s your primer.

Developing The Ultimate Open Source Radio Control Transmitter

April 3, 2019 by 10 Comments

While we’ve come a long way in terms of opening up the world of radio control to open source software, a good deal of the hardware itself is still closed up. You can flash a cheap RC transmitter with a community developed firmware, in fact there’s a decent chance that’s what it ships with, but the hardware itself is still an immutable black box. That might be fine if you’re just flying an RC plane or quadcopter, but what if you’ve got something a bit more advanced in mind?

An in-development version of the hardware.

To address this issue, [Alireza Safdari] has spent the last several years working on a truly open source RC transmitter that can be modified and augmented to meet the user’s needs, called the Alpha V1. With the hardware and software nearing completion, he’s looking to get some community feedback on the system before the planned crowdfunding campaign kicks off.

From his personal experience, [Alireza] found that traditional RC transmitters have their limits when you start using them for robotics. You’ll often want input schemes or devices which would never occur to the remote’s designers, and you’ll almost certainly want to have more channels and functions than the original hardware will allow. One of the big advantages with the Alpha V1 is that the front and back of the controller are simple acrylic panels, meaning you can easily cut openings or drill holes in them to add more hardware without having to deal with the (relatively) ergonomic shapes of a traditional transmitter.

Of course, that’s only one half of the equation. When you add new hardware, you’ll need to make the software aware of it. To that end, [Alireza] says he and his team have developed a library of adaptable firmware modules which should make it very easy to add in new components without having to get bogged down with software configuration. In fact, he says the goal is to allow the user to add new hardware to the Alpha V1 without requiring them to write a single line of code.

The Alpha V1 communicates at 2.4 GHz using either XBee or Murata DNT24 radios, and supports as many as 72 individual channels as well as two-way telemetry. If your requirements aren’t quite so high, we recently covered a significantly less intimidating attempt at building an open source RC transmitter that might suit your needs.

Eavesdropping On Cosmonauts With An SDR

March 28, 2019 by 9 Comments

Usually when we hear about someone making contact with astronauts in orbit, it’s an intentional contact between a ham on the ground and one of the licensed radio amateurs on the ISS. We don’t often see someone lucky enough to snag a conversation between ground controllers and a spacecraft en route to the ISS like this.

For [Tysonpower], this was all about being in the right place at the right time, as well as having the right equipment and the know-how to use it properly. Soyuz MS-12 launched from Baikonur on March 14 with cosmonaut [Aleksey Ovchinin] and NASA astronauts [Nick Hague] and [Kristina Koch] onboard, destined for the ISS after a six-hour flight. The lucky bit came when [Tysonpower] realized that the rendezvous would happen when the ISS was in a good position relative to his home in Cologne, which prompted him to set up his gear for a listening session. His AirSpy Mini SDR was connected to a home-brew quadrifilar helical (QFH) “eggbeater” antenna on his roof. What’s nice about this antenna is that it’s fixed rather than tracking, making it easy to get on the air with quickly. After digging around the aviation bands at about 121 MHz for a bit, [Tysonpower] managed to capture a few seconds of a conversation between [Ovchinin] and Moscow Flight Control Center. The commander reported his position and speed relative to the ISS a few minutes before docking. The conversation starts at about 1:12 in the video below.

We think it’s just cool that you can listen in on the conversations going on upstairs with a total of less than $50 worth of gear. Actually talking to the hams aboard the ISS is another matter, but not a lot more involved really.

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WiFi Your Door Lock With An ESP

March 25, 2019 by 18 Comments

The Internet of Things is upon us, and with that comes a deluge of smart cameras, smart home monitors, and smart home locks. There actually aren’t many smarts in these smart conveniences, and you can easily build your own. That’s what [MakerMan] did with some off-the-shelf parts and just a little bit of code. Now he can open his door with WiFi, and it’s a nice clean build.

The build process began by first removing the existing barrel bolt on the door. This was replaced by a deadbolt that also had some really neat solenoids inside for remote activation. This was mounted to the door in a way that the door could lock, with a minimal amount of damage from some skillful hacksaw work. The only thing left to do after this was add some electronics and brains to the lock.

For this, [MakerMan] added a button and LED to the outside of the door. Some of these wires were fed into the lock mechanism, with a few more run over to a project enclosure mounted next to a power outlet. The project enclosure holds an ESP-8266, power regulator, and relay board, and the ESP is running code that instantiates a web server that will unlock the door with a few clicks on a web page.

Sure, it’s probably not the most secure lock on the planet, and the 5V linear regulator is held on to the relay board with hot glue, but this is an exceptionally well-documented project, and all the code is available in an archive.

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