Toshiro Kodera: Electromagnetic Gyrotropes

We’ve learned a lot by watching the talks from the Hackaday Superconferences. Still, it’s a rare occurrence to learn something totally new. Microwave engineer, professor, and mad hacker [Toshiro Kodera] gave a talk on some current research that he’s doing: replacing natural magnetic gyrotropic material with engineered metamaterials in order to make two-way beam steering antennas and more.

If you already fully understood that last sentence, you may not learn as much from [Toshiro]’s talk as we did. If you’re at all interested in strange radio-frequency phenomena, neat material properties, or are just curious, don your physics wizard’s hat and watch his presentation. Just below the video, we’ll attempt to give you the Cliff’s Notes.

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Rust Running on the Realtek RTL8710: ESP8266 Alternative?

For simply getting your project connected to WiFi, a least among hacker circles, nothing beats the ESP8266. But it’s not the only player out there, and we love to see diversity in the parts and languages that we use. One of the big shortcomings of the ESP8266 is the slightly-oddball Xtensa CPU. It’s just not as widely supported by various toolchains as its ARM-based brethren.

And so, when [Zach] wanted to do some embedded work in Rust, the ESP8266 was out of the picture. He turned to the RTL8710, a very similar WiFi module made by Realtek. Documentation for the RTL8710 is, at the moment, crappy, much as the ESP8266 documentation was before the hacker community had at it. But in trade for this shortcoming, [Zach] got to use the LLVM compiler, which supports the ARM architecture, and that means he can code in Rust.

In the end, the setup that [Zach] describes is a mix of FreeRTOS and some of the mbed libraries, which should be more than enough to get you up and running fairly painlessly on the chip. We’ve actually ordered a couple of these modules ourselves, and were looking to get started in straight C, but having Rust examples working doesn’t hurt, and doesn’t look all that different.

Is anyone else using the RTL8710? An ARM-based, cheap WiFi chip should be interesting.

Adding an IKEA Wireless Charger to a Project

IKEA sometimes seems like a DIY store disguised as a furniture store. We may go there looking for a new sofa or kitchen table, but, to the DIY enthusiast, it’s a shop full of possibilities. While wandering through the local IKEA, [Erich Styger] noticed they had some Qi wireless chargers and receivers for a very reasonable price, so he bought a few and added wireless charging to his Mikroelektronika Hexiwear.

Removing the wireless charger

[Erich Styger] didn’t like the clumsiness of the Hexiwear’s USB charging options and, at the price he got the IKEA Vitahult Qi phone case wireless receivers at, he couldn’t resist buying a few for his projects. After carefully separating the circuitry from the phone cases they came in he opening up the Hexiwear. He removed the battery connector and soldered the charger to battery charging circuit. [Erich Styger] then 3D printed a new back to the Hexiwear’s case to fit the new circuitry. A quick test with the IKEA charging pad proved the hack had worked.

IKEA has become something of a DIY enthusiasts go-to shop, with everything from weather stations to a camera slider at a decent price. Walking through the maze inside the store, the DIYer doesn’t see lamps and boxes and shelves, they see light projectors and enclosures and, well, everyone needs shelves.

Track Wi-Fi Devices In Your Home

How do you audit your home Wi-Fi network? Perhaps you log into your router and have a look at the connected devices. Sometimes you’ll find an unexpected guest, but a bit of detective work will usually lead you to the younger nephew’s game console or that forgotten ESP8266 on your bench.

Wouldn’t it be useful if your router could tell you where all the devices connected to it are? If you are [Zack Scholl], you can do all this and more, for his FIND-LF system logs Wi-Fi probe requests from all Wi-Fi devices within its range even if they are not connected, and triangulates their position from their relative signal strengths across several sniffing receivers. These receivers are a network of Raspberry Pis with their own FIND-LF server, and any probe requests they pick up are forwarded to [Zack]’s FIND server (another of his projects) which does the work of collating the locations of devices.

It’s an impressive piece of work, though with a Raspberry Pi at each receiver it could get a little pricey. [Zack] has done other work in this field aside from the two projects mentioned here, his other work includes an implementation of the [Harry Potter] Marauder’s Map.

This is by no means the only indoor location system we’ve seen over the years. One that uses ESP8266 modules for example, or this commercial product that is similar to the project shown here.

These Ornaments Measure Christmas Cheer

The ornament projects we post around here tend to be simple, stand-alone projects. We are, however, well into the era of the Internet of Things (like it or not) and holiday ornaments need not be single, unconnected blinking objects. For Christmas this year, [Sean Hodgins]  came up with some connected DIY ornaments that respond to Christmas cheer.

[Sean Hodgins] had some beautiful PCBs done up in festive shapes and he hand-pastes and oven-solders the SMD components on both sides. Each one is battery powered and controlled by an ESP8266. LEDs and a button on the front of each ornament comprise the user interface. When the button is pressed, data is sent to a Phant server and a “Christmas Cheer” counter is incremented. Other ornaments, so long as they can connect to the Phant server, will periodically check the counter. If the Christmas Cheer has increased, the ornaments will play a tune and flash some lights.

The ornaments are open-source — [Sean Hodgins] posted the code and PCB designs on GitHub. They look great, and would be a good way to let people know you’re thinking of them over the holidays. Check out this light-up menorah or these lighted acrylic ornaments for more holiday fun!

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Interactive ESP8266 Development with PunyForth

Forth is one of those interesting languages that has a cult-like following. If you’ve never looked into it, its strength is that it is dead simple to put on most CPUs, yet it is very powerful and productive. There are two main principles that make this possible. First, parsing is easy because any sequence of non-space characters makes up a legitimate Forth word. So while words like “double” and “solve” are legal Forth words, so is “#$#” if that’s what you want to define.

The other thing that makes Forth both simple and powerful is that it is stack-based. If you are used to a slide rule or an HP calculator, it is very natural to think of “5+2*3” as “5 2 3 * +” but it is also very simple for the computer to interpret.

[Zeroflag] created PunyForth–a Forth-like language for the ESP8266. You can also run PunyForth for cross development purposes on Linux (including the Raspberry Pi). The system isn’t quite proper Forth, but it is close enough that if you know Forth, you’ll have no trouble.

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Password-Free Guest WiFi from Raspberry Pi

Anytime you’re having more than a handful of people over to your place for a wild rager or LAN party (or both), you’ll generally need a way to make sure everyone can get their devices on the network. Normally, this would involve either putting your WiFi password into more phones than you can count or yelling your password across a crowded room. Neither of these options suited [NicoHood] and his partner, however, so he came up with another more secure solution to the WiFi-in-a-crowded-room problem.

He calls his project “guestwlan” and it’s set up to run on a Raspberry Pi with a touch screen. When a potential WiFi user approaches the Pi and requests access to the network, the Pi displays a QR code. Within that code is all of the information that the prospective device needs to connect to the network. For those who have already spotted the new security vulnerability that this creates, [NicoHood] has his guest WiFi on a separate local network just to make sure that even if someone nefarious can access the Internet, it would be more difficult for them to do anything damaging to his local network. As it stands, though, it’s a lot more secure than some other WiFi networks we’ve seen.

[NicoHood] also released his software on Git but it has been configured for use with Arch. He says that it would probably work in a Debian environment (which the Raspberry Pi-specific OS is based on) but this is currently untested. Feel free to give it a try and let us know how it goes.