Wired Wireless Over Coax

If it’s stupid and it works, then it’s not stupid. There’s no better evidence of that than [Tobias]’ networking setup.

He recently had to distribute Ethernet through a building, and there are a few ways to do that. You can use regular ‘ol twisted pair, or fiber, but in this case running new cables wasn’t possible. WiFi would be the next obvious choice, the distance was just a bit too far for ‘regular’ WiFi links. Ethernet over power lines was an option, but there are amateur radio operators in the house, and they put out a bunch of interference and noise. The solution was to mis-use existing 75 Ohm satellite TV coax that was just sitting around.

The correct way to do this would be to use a standard DOCSIS modem and become your own cable Internet provider. The equipment to do this is expensive, and if you’re already considering running WiFI over coax, you’re too deep down the rabbit hole to spend real money. Instead, [Tobias] simply made a few u.FL to F-connector adapters from u.FL to SMA, then SMA to F-connector adapters.

There are some problems with this plan. WiFi is 50 Ohms, TV coax cable is 75 Ohms. Only one MIMO channel will be available meaning the maximum theoretical bandwidth will be 433 Mbps. WiFi is also at much higher frequencies than what coax is designed for.

With two WiFi antenna to coax adapters, [Tobias] simply connected the coax directly to a router set up to bridge Ethernet over WiFi. The entire thing worked, although testing showed it was only getting about 60 Mbps of throughput. That’s not bad for something that was cobbled together out of old parts and unused wiring. Is it surprising that this worked? No, not really, but you’ve probably never seen anyone actually do it. Here’s the proof it does work, and if you’re ever in a bind, this is how you make WiFi wired.

Which Wireless is Right Wireless?

Back in the early days of Arduino proliferation (and before you ask, yes we realize there was a time before that too), wireless was a strange and foreign beast. IR communication was definitely a thing. And if you had the funds there was this cool technology called ZigBee that was available, often in funny blue house-shaped XBee boards. With even more funds and a stomach for AT commands you could even bolt on a 2G cell radio for unlimited range. WiFi existed too, but connecting it to a hobbyist ecosystem of boards was a little hairier (though maybe not for our readership).

But as cell phones pushed demand for low power wireless forward and the progression of what would become the Internet of marking Terms (the IoT, of course) began, a proliferation of options appeared for wireless communication. Earlier this week we came across a great primer on some of the major wireless technologies which was put together by Digikey earlier in the year. Let’s not bury the lede. This table is the crux of the piece:

There are some neat entries here that are a little less common (and our old friend, the oft-maligned and never market-penetrating ZigBee). It’s actually even missing some entries. Let’s break it down:

  • Extremely short range: Just NFC. Very useful for transferring small amount of sensitive information slowly, or things with high location-relevance (like between phones that are touching).
  • Short range: BLE, Zigbee, Z-Wave, etc. Handy for so-called Personal Area Networks and home-scale systems.
  • Medium/long range: Wifi, Bluetooth, Zigbee, Z-Wave, LoRaWAN: Sometimes stretching for a kilometer or more in open spaces. Useful for everything from emitting tweets to stitching together a mesh network across a forrest, as long as there are enough nodes. Some of these are also useful at shorter range.
  • Very Long range/rangeless: Sigfox, NB-IoT, LTE Category-0. Connect anywhere, usually with some sort of subscription for network access. Rangeless in the sense that range is so long you use infrastructure instead of hooking a radio up to a Raspberry Pi under your desk. Though LoRa can be a fun exception to that.

You’re unlikely to go from zero to custom wireless solution without getting down into the mud with the available dev boards for a few different common protocols, but which ones? The landscape has changed so rapidly over the years, it’s easy to get stuck in one comfortable technology and miss the appearance of the next big thing (like how LoRaWAN is becoming new cool kid these days). This guide is a good overview to help catch you up and help decide which dev kits are worth a further look. But of course we still want to hear from you below about your favorite wireless gems — past, present, and future — that didn’t make it into the list (we’re looking at you 433 MHz).

Tiny WiFi-Enabled ARM MCU for Tiny Projects

Ever since the ESP8266 WiFi-enabled microcontroller came on the scene, it seemed like suddenly everyone came up with WiFi-enabled projects. But the ESP8266 is not the only game in town! Reader [PuceBaboon] notified us of a new product released by Seeed Studios: the imaginatively called Air602 WiFi Development Board.

The core of this board is the tiny WinnerMicro W600 MCU, which integrates a 32-bit ARM Cortex M3 CPU, along with dual UARTs, I2C, SPI and I2S interfaces, as well as a real-time clock (RTC). Add to this hardware crypto, seven I/O pins (five broken out on the development board) and you have a very capable WiFi-enabled MCU which can be programmed using the usual ARM development tools (e.g. Keil) using the provided SDK.

The W600 module can be bought by itself, in all its diminutive 12 mm x 10 mm glory, for a mere $1.90 as of time of writing – without antenna – as noted in [PuceBaboon]’s thoughts on this MCU and the development board.

Apple’s Best Computer Gets WiFi

The greatest computer Apple will ever make isn’t the Apple II, it isn’t the Bondi Blue iMac, it isn’t the trash can, and it certainly isn’t whatever overheating mess they’re pushing out now. The best computer Apple will ever make is the SE/30, at its time a server in a tiny portable shell, and capable of supporting 128 Megabytes of RAM thirty years ago.

Over the years, people have extended and expanded the SE/30 to absolutely ludicrous degrees, but now we have a simple way of adding WiFi to this classic computer. Over on the 68kmla forums, [ants] discovered a tiny cheap card that could easily serve as an Ethernet to WiFi bridge. After attaching this card to a Danaport Ethernet card and bending some aluminum for a bracket, they had a WiFi antenna sticking out of the back of a 30-year-old computer.

But adding a WiFi card to an old computer is nothing new — this could have been done with a Pi, or if you’re a hacker, a TP-Link router flashed with OpenWRT. To really do this right, you’ll need integration with the operating system, and that’s where this build goes off the rails. [ants] wrote a WiFi extension for System 7 (with the relevant GitHub)

The problem with the Vonets WiFi card is that configuration has to be done through a browser. Since there are no modern browsers for classic macs, this meant either pulling out a PowerBook or doing the configuration through your daily driver desktop PC. The WiFi extension gets around that by giving a classic mac the ability to configure the Vonets card almost automatically. This extension also looks like how you would configure the WiFi on a modern mac, complete with the WiFi icon in the toolbar. It’s beautiful, and one of the rare examples of modern 68k mac programming.

As for what you can do by adding WiFi to a 30-year-old computer with a 16MHz processor, the answer is a resounding, ‘not much’. Your choice of browsers is limited (iCab seems to be the best), but you can load the Google homepage slowly. HTTPS isn’t going to work, and the Internet right now is full of megabytes of Javascript cruft. If you find a nice, lightweight web page — such as the Hackaday Retro Edition, for example — you’re looking at a capable web browsing machine. Of course, the real use case for giving the SE/30 WiFi is file transfer around the home network, but still: it’s WiFi for the best computer Apple ever made.

I Hear You Offer WiFi

We are swimming in radio transmissions from all around, and if you live above the ground floor, they are coming at you from below as well. Humans do not have a sensory organ for recognizing radio signals, but we have lots of hardware which can make sense of it. The chances are good that you are looking at one such device right now. [Frank Swain] has leaped from merely accepting the omnipresent signals from WiFi routers and portable devices to listening in on them. The audio signals are mere soundwaves, so he is not listening to every tweet and email password, merely a representation of the data’s presence. There is a sample below the break, and it sounds like a Geiger counter playing PIN•BOT.

We experience only the most minuscule sliver of information coming at us at any given moment. Machines to hack that gap are not had to find on these pages so [Frank] is in good company. Magnetosensory is a popular choice for people with a poor sense of direction. Echolocation is perfect for fans of Daredevil. Delivering new sensations could be easier than ever with high-resolution tactile displays. Detect some rather intimate data with ‘SHE BON.’

Continue reading “I Hear You Offer WiFi”

Touch Anything And Everything

Powering IoT devices is often a question of batteries or mains power, but in rare exceptions to this rule there is no power supply (PDF Warning). At the University of Wisconsin-Madison and the University of California, San Diego, researchers have gone the extra mile to make advanced backscatter devices, and these new tags don’t need the discrete components we have seen in previous versions. They are calling it LiveTag, and it doesn’t need anything aside from a layer of foil printed or etched on a flexible ceramic-PTFE laminate. PTFE is mostly seen in the RF sector as a substrate for circuit boards.

We have seen some of the wild creations with wifi backscatter that range from dials to pushbuttons. RF backscatter works by modulating the RF signals in which we are continuously swimming. Those radio waves power the device and disrupt the ambient signals, which disruption can be detected by a receiver. With a BOM that looks like a statement more than a list, integration with many devices becomes a cost-effective reality. Do not however broadcast important data because you cannot expect great security from backscatter.

[Via IEEE Spectrum]

Turning Cheap WiFi Modules Into Cheap WiFi Swiss Army Knives

When the ESP8266 was released, it was sold as a simple device that would connect to a WiFi network over a UART. It was effectively a WiFi modem for any microcontroller, available for just a few bucks. That in itself is awesome, but then the hackers got their hands on it. It turns out, the ESP8266 is actually a very capable microcontroller as well, and the newest modules have tons of Flash and pins for all your embedded projects.

For [Amine]’s entry to the Hackaday Prize, he’s using the ESP8266 as the ultimate WiFi Swiss Army knife. The Kortex Xttend Lite is a tiny little WiFi repeater that’s capable of doing just about anything with a WiFi network, and with a bit of added hardware, can connect to Ethernet as well.

The hardware on this board sports an ESP8266-07S module, with two free GPIO pins for multiple functions. There’s a USB to UART in there, and a voltage regulator that’s capable of outputting 600mA for the slightly power hungry radio. There’s also an integrated battery management and charge controller, allowing this board to charge an off-the-shelf lithium cell and run for hours without any wires at all.

So, what can this board do? Just about everything you would want for a tiny little WiFi Swiss Army knife. There’s traffic shaping, port mapping, packet sniffing, and even support for mesh networking. There’s also an SMA connector on there, so grab your cantennas — this is a great way to extend a WiFi network, too.

This is a well-designed and well-executed project, and what makes this even more amazing is that this was done as one of [Amine]’s high school projects. Yes, it took about a year to finish this project, but it’s still amazing work for [Amine]’s first ‘high-complexity’ design. That makes it an excellent learning experience, and an awesome entry to this year’s Hackaday Prize.