A 60 GHz Phased Array

Our friend [Hunter Scott] gave a talk at a past Supercon about phased array antennas. He mentioned he was looking for collaborators to create an antenna with the SiBeam SB9210 chip. This is a specialized chip for WirelessHD, a more or less failed video streaming protocol, and it’s essentially an entire 60 GHz phased array on a chip with both transmit and receive capabilities. For $15, it seems like quite the bargain, and [Hunter] still wants to put the device to work.

The downside is that Lattice bought SiBeam and killed this chip — not surprising considering WirelessHD never really took off. However, [Hunter] says the chip was in some old smart TVs and laptops. If you can find replacement boards for those devices on the surplus market, you can get the chip and the supporting circuitry for a song.

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The Internet Of Football

While football in the United States means something totally different from what it means in the rest of the world, fans everywhere take it pretty seriously. This Sunday is the peak of U.S. football frenzy, the Super Bowl, and it is surprisingly high-tech. The NFL has invested in a lot of technology and today’s football stats are nothing like those of the last century thanks to some very modern devices.

It is kind of interesting since, at the core, the sport doesn’t really need a lot of high tech. A pigskin ball, some handkerchiefs, and a field marked off with some lime and a yardstick will suffice. However, we’ve seen a long arc of technology in scoreboards, cameras — like instant replay — and in the evolution of protective gear. But the last few years have seen the rise of data collection. It’s being driven by RFID tags in the player’s shoulder pads.

These aren’t the RFID chips in your credit card. These are long-range devices and in the right stadium, a computer can track not only the player’s position, but also his speed, acceleration, and a host of other statistics.

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This Is It For The Particle Mesh Network

The long-held dream of wireless network hackers everywhere is to dispense with centralised network infrastructure, and instead rely on a distributed network in which the clients perform the role of distribution and routing of traffic. These so-called mesh networks promise scalability and simplicity on paper, but are in practice never as easy to implement as the theory might suggest. Much venture capital has been burned over the years by startups chasing that particular dream, yet most of our wireless connectivity still follows a hub topology.

An exciting development in our sphere concerning mesh networking came in early 2018, when Particle, the purveyors of wireless-equipped dev boards, launched their third generation of products. These offered mesh networking alongside their other features, but this week they have announced that they’ll no longer be developing that particular side of their offering. The Wi-Fi-equipped Argon and Cellular-equipped Boron will remain on sale, but they will henceforth discontinue the mesh-only Xenon. Existing owners of the now orphaned board will be compensated with store credit.

Their rationale for discontinuing mesh networking is interesting, and reflects on the sentiment in our first paragraph. Mesh networking is hard, and in particular their attempt to make it work with zero configuration was simply not successful. But then they talk about the realisation that maybe mesh networking was not the right solution for the IoT applications the boards were being used in, and perhaps another technology such as LoRa would be more appropriate.

So the mesh experiment from Particle is over, but the company and its connected dev boards are very much still with us. We salute them for being bold enough to try it, and we wonder when we’ll next find a piece of similar mesh networking hardware.

Poking Around The Wide World Of Bluetooth

Bluetooth is a technology with a very interesting history. When it first came around in the late 1990s, it promised to replace the mess of wires that was tucked behind every desk of the day. Unfortunately, the capabilities of early Bluetooth didn’t live up to the hype, and it never quite took off. It wasn’t until the rise of the smartphone more than a decade later that Bluetooth, now several versions more advanced, really started to make sense.

As [Larry Bank] explains in a recent blog post, that means there’s a whole lot to learn if you want to really understand Bluetooth hacking. For example, the Bluetooth versions that were used in the 1990s and 2000s are actually a completely different protocol from that which most modern devices are using. But the original protocol, now referred to as “Classic”, is still supported and in use.

That means to really get your head wrapped around working with Bluetooth, you need to learn about the different versions and all the tools and tricks associated with them. To that end, [Larry] does a great job of breaking down the primary versions of Bluetooth and the sort of tools you might find yourself using. That includes microcontrollers such as the ESP32 or Arduino Nano 33 BLE.

But the post isn’t just theory. [Larry] also goes over a few real-world projects of his that utilize Bluetooth, such as getting a portable printer working with his Arduino, or figuring out how to use those tiny mobile phone game controllers for his own purposes. Even if you don’t have these same devices, there’s a good chance that the methods used and lessons learned will apply to whatever Bluetooth gadgets you’ve got your eye on.

Readers may recall [Larry] from our previous coverage of his exploits, such as his efforts to increase the frame rate of the SSD1306 OLED display or his wireless bootloader for the SMART Response XE. Whenever we see his name pop up in the Tip Line, we know a fascinating hardware deep dive isn’t far behind.

NanoVNA Tests Antenna Pattern

When [Jephthai] wanted to build his own Yagi antenna, he turned to MMANA software for antenna modeling. This is an antenna analysis program that uses the moment method to calculate parameters for different antenna geometries. After building the Yagi, the predicted tuning and impedance matched the real antenna nicely. But what about the radiation pattern? To test that, he used a NanoVNA and a clever test setup.

He needed a test spot out of the antenna’s near field so he set up his workstation 18 feet away from the test antenna which was on a mount that could rotate. On the edge of the workstation table — affixed with painter’s tape — is a NanoVNA connected to a laptop.

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Full Duplex Radio Claimed Easier With Analog Module

There’s an old saying that we have one mouth and two ears so you can listen twice as much as you talk. However, talking and listening at the same time is fairly difficult and doing it with radio signals is especially hard. A company called Kumu Networks has an analog module that can use self-interference cancellation which allows transmitting and receiving on the same frequency with around 50 dB of the transmitted signal in the transceiver. You can see a video about Kumu’s claims its technology below.

You may think that cell phones and ham radio repeaters transmit and receive at the same time, which of course they do, but usually on different frequencies to avoid direct interference. A diplexer is a device that sorts out the two frequencies while a duplexer sorts them out by the direction of the signal, but they are tricky to use. A duplexer can operate on a single frequency in applications such as radar, and even then it is still very difficult to prevent leakage from the transmitter from overloading and desensitizing the receiver.

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36C3: All Wireless Stacks Are Broken

Your cellphone is the least secure computer that you own, and worse than that, it’s got a radio. [Jiska Classen] and her lab have been hacking on cellphones’ wireless systems for a while now, and in this talk gives an overview of the wireless vulnerabilities and attack surfaces that they bring along. While the talk provides some basic background on wireless (in)security, it also presents two new areas of research that she and her colleagues have been working on the last year.

One of the new hacks is based on the fact that a phone that wants to support both Bluetooth and WiFi needs to figure out a way to share the radio, because both protocols use the same 2.4 GHz band. And so it turns out that the Bluetooth hardware has to talk to the WiFi hardware, and it wouldn’t entirely surprise you that when [Jiska] gets into the Bluetooth stack, she’s able to DOS the WiFi. What this does to the operating system depends on the phone, but many of them just fall over and reboot.

Lately [Jiska] has been doing a lot of fuzzing on the cell phone stack enabled by some work by one of her students [Jan Ruge] work on emulation, codenamed “Frankenstein”. The coolest thing here is that the emulation runs in real time, and can be threaded into the operating system, enabling full-stack fuzzing. More complexity means more bugs, so we expect to see a lot more coming out of this line of research in the next year.

[Jiska] gives the presentation in a tinfoil hat, but that’s just a metaphor. In the end, when asked about how to properly secure your phone, she gives out the best advice ever: toss it in the blender.