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.

More Blinky = More Better – The WS2812FX Library

The WS2812 is an amazing piece of technology. 30 years ago, high brightness LEDs didn’t even exist yet. Now, you can score RGB LEDs that even take all the hard work out of controlling and addressing them! But as ever, we can do better.

Riffing on the ever popular Adafruit NeoPixel library, [Harm] created the WS2812FX library. The library has a whole laundry list of effects to run on your blinkenlights – from the exciting Hyper Sparkle to the calming Breathe inspired by Apple devices. The fantastic thing about this library is that it can greatly shorten development time of your garden-variety blinkables – hook up your WS2812s, pick your effect, and you’re done.

[Harm]’s gone and done the hard yards, porting this to a bevy of platforms – testing it on the Arduino Nano, Uno, Micro and ESP8266. As a proof of concept, they’ve also put together a great demonstration of the software – building some cute and stylish Christmas decorations from wood, aluminium, and hacked up Christmas light housings. Combining it with an ESP8266 & an app, the effects can be controlled from a smartphone over WiFi. The assembly video on YouTube shows the build process, using screws and nails to create an attractive frame using aluminium sheet.

This project is a great example of how libraries and modern hardware allow us to stand on the shoulders of giants. It’s quicker than ever to build amazingly capable projects with more LEDs than ever. Over the years we’ve seen plenty great WS2812 projects, like this sunrise alarm clock or this portable rave staff.
As always, blink hard, or go home. Video after the break.

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Creepy Wireless Stalking Made Easy

In a slight twist on the august pursuit of warwalking, [Mehdi] took a Raspberry Pi armed with a GPS, WiFi, and a Bluetooth sniffer around Bordeaux with him for six months and logged all the data he could find. The result isn’t entirely surprising, but it’s still a little bit creepy.

If your WiFi sends out probe requests for its home access points, [Mehdi] logged it. If your Bluetooth devices leak information about what they are, [Mehdi] logged it. In the end, he got nearly 30,000 WiFis logged, including 120,000 probes. Each reading is timestamped and geolocated, and [Mehdi] presents a few of the results from querying the resulting database.

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A Smart Wand for all us Muggles

Arthur C. Clarke said that “any sufficiently advanced technology is indistinguishable from magic.” Even though we know that something isn’t “magic”, it’s nice to see how close we can get. [Dofl] and his friends, big fans of the magic in Harry Potter, thought the same thing, and decided to create a magic wand that they could use themselves.

muggle-wand-internalsThe wand itself is 3D printed and has a microcontroller and WiFi board, a voice recognition board, a microphone, and a vibrating motor stuffed inside. The wand converts the voice into commands and since the wand is connected to WiFi, the commands can be used to communicate with your WiFi connected lights (or your WiFi connected anything, really.) Five voice commands are recognized to turn on and off music, the lights, and a “summon” command which is used in the video to request a hamburger from For feedback, the motor is vibrated when a command is recognized.

There’s not much technical information in the original article, but I’m sure our readers could figure out the boards used and could suggest some alternatives to get the wand’s form factor down a bit.  Over the years, other wands have appeared on our pages, using some different technologies.  It’s a fun way to interact with the environment around you, even if you know the “magic” involved is just boring old technology.

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ZX81 Connects to the Network


[Victor Trucco] makes us wish we spoke Portuguese. He’s done a lot of retrocomputing projects including connecting a ZX81 to the Internet to load programs. The project uses — what else — an ESP8266 to get the WiFi communications. You can see a video below if you want to exercise your high school Portuguese.

It is somewhat ironic that the ZX81’s CPU is kept busy driving the video, reading the keyboard, and running about just over 3 MHz which doesn’t even translate into 3 MIPS on that processor. Meanwhile, the “servant” ESP8266 has a 32-bit Tensilica CPU running at 80 MHz. Times have changed.

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WarWalking With The ESP8266

[Steve] needed a tool to diagnose and fix his friend’s and family’s WiFi. A laptop would do, but WiFi modules and tiny OLED displays are cheap now. His solution was to build a War Walker, a tiny handheld device that would listen in WiFi access points, return the signal strength, and monitor the 2.4GHz environment around him.

The War Walker didn’t appear out of a vacuum. It’s based on the WarCollar Dope Scope, a tiny, portable device consisting of an off-the-shelf Chinese OLED display, an ESP8266 module, and a PCB that can charge batteries, provide a serial port, and ties the whole thing together with jellybean glue. The Dope Scope is a capable device, but it’s marketed towards the 1337 utilikilt-wearing, The Prodigy-blasting pentesters of the world. It is, therefore, a ripoff. [Steve] can build his version for $6 in materials.

The core of the build is an ESP-based carrier board built for NodeMCU. This board is available for $3.77 in quantity one, with free shipping. A $2 SPI OLED display is the user interface, and the rest of the circuit is just some perfboard and a few wires.

The software is based on platformio, and dumps all the WiFi info you could want over the serial port or displays it right on the OLED. It’s a brilliantly simple device for War Walking, and the addition of a small LiPo makes this a much better value than the same circuit with a larger pricetag.

A Lot Of WiFi Power, A Yagi, And A Sniper’s ‘Scope

Do you remember the early days of consumer wireless networking, a time of open access points with default SSIDs, manufacturer default passwords, Pringle can antennas, and wardriving? Fortunately out-of-the-box device security has moved on in the last couple of decades, but there was a time when most WiFi networks were an open book to any passer-by with a WiFi-equipped laptop or PDA.

The more sophisticated wardrivers used directional antennas, the simplest of which was the abovementioned Pringle can, in which the snack container was repurposed as a resonant horn antenna with a single radiator mounted on an N socket poking through its side. If you were more sophisticated you might have used a Yagi array (a higher-frequency version of the antenna you would use to receive TV signals). But these were high-precision items that were expensive, or rather tricky to build if you made one yourself.

In recent years the price of commercial WiFi Yagi arrays has dropped, and they have become a common sight used for stretching WiFi range. [TacticalNinja] has other ideas, and has used a particularly long one paired with a high-power WiFi card and amplifier as a wardriver’s kit par excellence, complete with a sniper’s ‘scope for aiming.

The antenna was a cheap Chinese item, which arrived with very poor performance indeed. It turned out that its driven element was misaligned and shorted by a too-long screw, and its cable was rather long with a suspect balun. Modifying it for element alignment and a balun-less short feeder improved its performance no end. He quotes the figures for his set-up as 4000mW of RF output power into a 25dBi Yagi, or 61dBm effective radiated power. This equates to the definitely-illegal equivalent of an over 1250W point source, which sounds very impressive but somehow we doubt that the quoted figures will be achieved in reality. Claimed manufacturer antenna gain figures are rarely trustworthy.

This is something of an exercise in how much you can push into a WiFi antenna, and his comparison with a rifle is very apt. Imagine it as the equivalent of an AR-15 modified with every bell and whistle the gun store can sell its owner, it may look impressively tricked-out but does it shoot any better than the stock rifle in the hands of an expert? As any radio amateur will tell you: a contact can only be made if communication can be heard in both directions, and we’re left wondering whether some of that extra power is wasted as even with the Yagi the WiFi receiver will be unlikely to hear the reply from a network responding at great distance using the stock legal antenna and power. Still, it does have an air of wardriver chic about it, and we’re certain it has the potential for a lot of long-distance WiFi fun within its receiving range.

This isn’t the first wardriving rifle we’ve featured, but unlike this one you could probably carry it past a policeman without attracting attention.