Before smartphones and Internet of Things devices were widely distributed, the Automatic Packet Reporting System (APRS) was the way to send digital information out wirelessly from remote locations. In use since the 80s, it now has an almost hipster “wireless data before it was cool” vibe, complete with plenty of people who use it because it’s interesting, and plenty of others who still need the unique functionality it offers even when compared to more modern wireless data transmission methods. One of those is [Tyler] who shows us how to build an APRS system for a minimum of cost and size.
[Tyler]’s build is called Arrow and operates on the popular 2 metre ham radio band. It’s a Terminal Node Controller (TNC), a sort of ham radio modem, built around an ESP32. The ESP32 handles both the signal processing for the data and also uses its Bluetooth capability to pair to an Android app called APRSDroid. The entire module is only slightly larger than the 18650 battery that powers it, and it can be paired with a computer to send and receive any digital data that you wish using this module as a plug-and-play transceiver.
While the build is still has a few limitations that [Tyler] notes, he hopes that the project will be a way to modernize the APRS protocol using methods for radio transmission that have been improved upon since APRS was first implemented. It should be able to interface easily into any existing ham radio setup, although even small balloon-lofted radio stations can make excellent use of APRS without any extra equipment. Don’t forget that you need a license to operate these in most places, though!
A common sight on factory floors, stack lights are used to indicate the status of machinery to anyone within visual range. But hackers have found out you can pick them up fairly cheap online, so we’ve started to see them used as indicators in slightly more mundane situations than they were originally intended for. [Tyler Ward] recently decided he wanted his build own network controlled stack light, and thought it would double as a great opportunity to dive into the world of Power Over Ethernet (PoE).
Now the easy way to do this would be to take the Raspberry Pi, attach the official PoE Hat to it, and toss it into a nice enclosure. Write some code that toggles the GPIO pins attached to the LEDs in the stack light, and call it a day. Would be done in an afternoon and you could be showing it off on Reddit by dinner time. But that’s not exactly what [Tyler] had in mind.
On the software side [Tyler] has developed a firmware for the ESP32 that supports both Art-Net and RDM protocols, which are subsets of the larger DMX protocol. That means the controller should be compatible with existing software designed for controlling theatrical lighting systems. If you’d rather take a more direct approach, the firmware also sports a web interface and simple HTTP API to provide some additional flexibility.
Inside is an ESP32 running TensorFlow Lite to read in the gestures from the two touchpads. The pad at the top is a volume slider, and the square touchpad is the main input and is used in conjunction with the buttons to run AutoHotKey scripts within certain programs. [jakkra] can easily run git commands and more with a handful of simple gestures. The gestures all seem like natural choices to us: > for next media track, ∧ to push the current branch and ∨ to fetch and pull the current branch, s for git status, l for git log, and the one that sounds really useful to us — draw a C to get a notification that lists all the COM ports. One of the switches is dedicated to Bluetooth pairing and navigating menus on the OLED screen.
We love the combination of inputs here and think this looks great, especially with the double touchpad design. Be sure to check out the gesture demo gif after the break.
Ferris Bueller’s Day Off is a pop culture classic, and remains one of the standout teen films of the era. Notably, titular character Ferris was somewhat of a hacker himself, with the movie showcasing several contraptions the teenager used to get out of a day of school. Among them was the intercom, which [Aaron] faithfully recreated with modern technology.
For those who haven’t seen the film, the intercom was hooked up to a cassette player to feign a believable response to anyone that visited the house while Ferris was away. Rather than do things the old fashioned way, [Aaron] built his replica using an ESP32 fitted with a sound chip instead. When visitors ring the intercom, it plays back sound clips from the movie, while also signalling another ESP microcontroller inside [Aaron]’s house to let him know he has visitors.
The build is a charming tribute to the classic film, and all the more fun for [Aaron’s] efforts to make it look the part as well, choosing to build it inside a period-correct intercom housing. To avoid confusion for those who haven’t seen the film, however, he’s been careful to place a sign up to clarify the intercom is not as it seems.
It’s true; hackers like clocks. And hackers like useless machines. But would they like an intersection of the two? We’re thinking yes, probably, though we would argue that this QR clock was at no point fully useless. Yes, a QR clock as in, whip out your phone and, ignoring the conveniently-available phone time, open the bar code reader so you can check the time on this thing. So, it’s semi-useless. But at least it doesn’t detect cameras and then hide the QR code. That would be evil.
This project started life as a display piece for the hex wall down at [megardi]’s hackerspace, but, state of the world being what it is, [megardi] hasn’t made it down there yet. And meanwhile this little guy was looking cuter and cuter, so [megardi] decided to make him more useful and freestanding. The ESP32 inside gets the official time from NIST and displays it on the 1.5″ OLED screen. It also has a single alarm now, along with some other non-QR code clock faces that display the time in various ways.
We really like the look of this clock. Honestly, with those uniform tics around the edge, it sort of reminds us of the doomsday clock — you know, the ‘minutes to midnight’ quarter clock face that shows the current perceived threat level of how close we are to destroying the world with the technologies we’ve created. That clock is kind of cute, too, which is a little bit weird considering what it represents.
WiFi is one of those technologies that most of us would have trouble living without. Unfortunately, there are several vulnerabilities in the underlying 802.11 standards that could potentially be exploited. To demonstrate just how simple this can be, [risinek] developed the ESP32 Wi-Fi Penetration Tool that runs on cheap dev boards and can execute deauthentication and Denial of Service attacks, and capture handshakes and PMKIDs.
The main challenge in this project is to implement these attacks while using the ESP-IDF development framework. The closed source WiFi libraries of the ESP-IDF block specific arbitrary frames like deauthentication frames. To get around this [risinek] used two different approaches. The first is to bypass the declaration of the blocking function at compile-time, which is borrowed from the esp32-deauther project. The second approach doesn’t require any modifications to the ESP-IDF. It works by creating a rogue access point (AP) identical to the targeted access point, which will send a deauthentication frame whenever one of the devices tries to connect to it instead of the real AP.
WPA/WPA2 handshakes are captured by passively listening for devices connecting to the target network, or running a deauth attack and then listening for when devices reconnect. PMKIDs are captured from APs with the roaming feature enabled, by analyzing the first message of a WPA handshake. ESP32 Wi-Fi Penetration Tool will also format the captured data into PCAP and HCCAPX files ready to be used with Wireshark and Hashcat. To manage the tool, it creates a management access point where the target and attack type is selected, and the resulting data can be downloaded. Pair the ESP32 with a battery, and everything can be done on the go. The project is part of [risinek]’s master’s thesis, and the full academic article is an educating read. Continue reading “WiFi Penetration Testing With An ESP32”→
Great news for fans of [Voidstar Labs] — [Zack] is going to be streaming future builds live on YouTube instead of trying to keep up with a grueling and limiting schedule of releasing a build video every week. The only problem is that the wall behind him is totally blank and boring, which matters quite a bit for pretty much any streamer that doesn’t broadcast from a hot tub. Well, not anymore! Now the wall has twenty square feet of rainbow hexagons, because blinkenlights.
But these aren’t just any blinkenlights. They’re informative. They dance to the beat of [Zack]’s bio-metrics, or in other words, they are visualizing how sweaty and anxious [Zack] may be at a given moment, and turning that information into art.
At the heart of this build is a brand-new bio-metric board called the EmotiBit which boasts sixteen sensors in a small package, including a pulse oximeter. The EmotiBit sends vitals to [Zack]’s PC, which is running an oscilloscope app to interpret the signals. Then they are sent over Open Sound Control to an ESP32, which runs the light show.
Like [Zack] says in the video after the break, this isn’t a terribly difficult project, but the construction takes time. [Zack] used aluminum extrusion meant for under-cabinet lighting and ran forty strips of fourteen DotStar LEDs each. The nodes are printed in carbon-fiber PLA and hold the lights away from the wall so it looks cooler. Worried about the current draw? It’s okay, because the brightness and number of lit LEDs at any one time is limited. Add in the fact that none of the LEDs are ever turned off — they fade by one percent each loop — and you have some really cool animations. Check them out after the break.