wifi

469 Articles

7-Segment Digits Slide Stylishly On This OLED Clock

October 2, 2017 by 19 Comments

Over at Sparkfun, [Alex] shared an OLED clock project that’s currently in progress but has a couple interesting twists. The first is the use of a small OLED screen for each digit, to which [Alex] added a stylistic touch. Digits transition by having segments slide vertically in a smooth animated motion. It’s an attractive effect, and the code is available on his github repository for anyone who wants to try it out.

[Alex] also found that by using an ESP32 microcontroller and synchronizing the clock via NTP over WiFi, the added cost of implementing a real-time clock in hardware becomes unnecessary. Without an RTC, time would drift by a few seconds every day and require a reset. At the moment the clock requires the SSID and password to be hardcoded, but [Alex] would prefer to allow this to be configured via a web page and could use some help. If you have implemented a web server on the ESP32, [Alex] would like to know how you handled multiple pages. “I’ve been scratching my head throughout the build on how to get this done,” he writes. “With the ESP8266, there’s on(const String &uri, handler function), but that seems to have been removed on the ESP32.” If you can point [Alex] in the right direction, be sure to pipe up.

OLED displays and clocks often go together, as we have seen with projects like the DIY OLED Smart Watch, but it’s nice to see someone using the OLED’s strengths to add some visual flair to an otherwise plain display.

Simultaneous AP & Client On The Pi Zero W

September 29, 2017 by 34 Comments

The Raspberry Pi Zero W is a great platform for IoT projects, with a smattering of GPIO and onboard WiFi. However, security is an important consideration when it comes to the Internet of Things and it can be beneficial to keep your IoT devices on a separate network for safety’s sake. [Albert] wanted to do this all on board the Pi Zero W, and figured out how to get it acting as an access point and a client all at the same time.

[Albert] starts off with a fresh install of Raspbian Stretch, and sets the Pi up in OTG mode. This allows access to the Pi over a USB serial terminal. This is great for productivity when working on headless networking projects, as it can be frustrating trying to work with an SSH session that keeps dropping out when you change settings.

After creating a second named device (ap0) to go along with the one created automatically by the kernal (wlan0), DNSmasq is installed to act as a DHCP server for the AP. Hostapd is then installed to control the AP settings. Following this, like anything in Linux, a flurry of configuration files are edited to get everything humming along and starting up automatically after a reboot. For some reason, things don’t start up smoothly, so [Albert] has a cron job that fires 30 seconds after bootup and toggles the interfaces off and on again, and that’s done the trick.

It’s a useful hack, as it allows the Pi Zero to act as a hub for IoT devices, while also creating a bridge between them and the internet. Traffic can be managed to stop random internet users flicking your lights on and off and overspeeding your dishwasher.

We’ve seen the Pi Zero used for just about everything under the sun so far. If you’re just starting your own IoT build, perhaps you’d like to use the Pi Zero as a streaming camera?

 

DIY Wireless Sprinkler System? Don’t Mind If I Do.

September 5, 2017 by 13 Comments

What to do once you have a sprinkler system installed on your property: buy a sprinkler control system or make your own? The latter, obviously.

[danaman] was determined to hack together a cheap, IoT-enabled system but it wasn’t easy — taking the better part of a year to get working. Instead of starting right from scratch, he used the open-source Sustainable Irrigation Platform(SIP) control software — a Python sprinkler scheduler with some features [danman] was looking for(eg: it won’t activate if there’s rain in the forecast). Since he wasn’t running it with a Raspberry Pi as recommended, [danman] wrote a Python plugin that runs on his home server as a daemon which listens to TCP port 20000 for connections and then updates the relevant relays. Ok, software done; on to the relay controller box!

Continue reading “DIY Wireless Sprinkler System? Don’t Mind If I Do.” →

WiFi Deauthentication VS WiFi Jamming: What Is The Difference?

August 13, 2017 by 24 Comments

Terminology is something that gets us all mixed up at some point. [Seytonic] does a great job of explaining the difference between WiFi jammers and deauthenticators in the video embedded below. A lot of you will already know the difference however it is useful to point out the difference since so many people call deauth devices “WiFi Jammers”.

In their YouTube video they go on to explain that jammers basically throw out a load of noise on all WiFi channels making the frequencies unusable in a given distance from the jammer. Jammers are also normally quite expensive, mostly illegal, and thus hard to find unless of course you build your own.

WiFi deauthentication on the other hand works in a very different way. WiFi sends unencrypted packets of data called management frames. Because these are unencrypted, even if the network is using WPA2, malicious parties can send deauthentication commands which boot users off of an access point. There is hope though with 802.11w which encrypts management frames. It’s been around for a while however manufacturers don’t seem bothered and don’t implement it, even though it would improve the security of a WiFi device from these types of attacks.

Continue reading “WiFi Deauthentication VS WiFi Jamming: What Is The Difference?” →

Broadpwn – All Your Mobiles Are Belong To Us

July 29, 2017 by 50 Comments

Researchers from Exodus Intel recently published details on a flaw that exists on several Broadcom WiFi chipsets. It’s estimated to affect nearly 1 Billion devices, from Android to iPhone. Just to name a few in the top list:

  • Samsung Galaxy from S3 through S8, inclusive
  • All Samsung Notes3. Nexus 5, 6, 6X and 6P
  • All iPhones after iPhone 5

So how did this happen? And how does a bug affect so many different devices?

A smart phone nowadays is a very complicated mesh of interconnected chips. Besides the main processor, there are several other secondary processors handling specialized tasks which would otherwise clog up the main CPU. One of those is the WiFi chipset, which is responsible for WiFi radio communications — handling the PHY, MAC and MLME layers. When all the processing is complete, the radio chipset hands data packets over the kernel driver, which runs on the main CPU. This means that the radio chipset itself has to have some considerable data processing power to handle all this work. Alas, with great power comes great responsibility.

Continue reading “Broadpwn – All Your Mobiles Are Belong To Us” →

Hackaday Prize Entry: Don’t Build This

July 24, 2017 by 28 Comments

The ESP8266 is a remarkable piece of hardware. What we originally thought — and what was originally marketed as — a simple UART to WiFi bridge with Hayes modem commands has turned into one of the best embedded platforms around. It’s a powerful little microcontroller, it has WiFi, and it can send raw frames. That last bit is awesome, because it allows for some mischief or mirth making, depending on your point of view.

For his Hackaday Prize entry, [Tejas] is building a WiFi Jammer with an ESP8266. It’s a small device that is able to disconnect anyone from a WiFi AP. Should you build it? No. Can you? Sure, why not.

The code for this WiFi hacking tool is taken from the creator of the ESP8266 deauth toolkit, [spacehuhn], although [Tejas] is violating the license for [spacehuhn]’s (non-Open Source) code. This fantastic piece of firmware uses management packets to send a deauthentication frame, effectively allowing anyone to disconnect any device from a WiFi router. Why would anyone want to do this? Mischief, of course, but there are also a few techniques that could allow an attacker to get a password for the WiFi.

While there are ways to protect against deauth attacks, most routers don’t have management-frame protection enabled. In any event, we’re going to see exactly how annoying deauth attacks can be this week at DEF CON. The smart money is on a small percentage of DEF CON attendees lulzing about with ESPs and the Caesar’s CTO being very, very unhappy.

The HackadayPrize2017 is Sponsored by:

ESP To Wireshark

July 6, 2017 by 13 Comments

Everyone’s favorite packet sniffing tool, Wireshark, has been around for almost two decades now. It’s one of the most popular network analysis tools available, partially due to it being free and open source. Its popularity guaranteed that it would eventually be paired with the ESP32/8266, the rising star of the wireless hardware world, and [spacehuhn] has finally brought these two tools together to sniff WiFi packets.

The library that [spacehuhn] created uses the ESP chip to save Pcap files (the default Wireshark filetype) onto an SD card or send the data over a serial connection. The program runs once every 30 seconds, creating a new Pcap file each time. There are many example scripts for the various hardware you might be using, and since this is written for the ESP platform it’s also Arduino compatible. [spacehuhn] has written this as a proof-of-concept, so there are some rough edges still, but this looks very promising as a network analysis tool.

[spacehuhn] is no stranger to wireless networks, either. His YouTube channel is full of interesting videos of him exploring various exploits and testing other pieces of hardware. He’s also been featured here before for using an ESP8266 as a WiFi jammer.

Continue reading “ESP To Wireshark” →