Ham Radio Mobile Operations Circa 1919

You used to be able to tell a die-hard ham radio operator on the road by the number and length of antennas protruding porcupine-like from their vehicle. There are still some mobile high frequency operators that have respectable car-mounted antenna farms, but they have nothing on Alfred H. Grebe. In 1919, he fitted a medium wave transmitter in his car that operated around 2 MHz. Since it needed a very large antenna, Grebe rigged a wire antenna that looked like a clothesline between the two bumpers. Obviously, you had to stop, set up your antenna, and then operate — you couldn’t talk and drive. But this may have been the world’s first automotive radio setup for voice communication.

The car had a separate battery for the radio and a dynamotor to generate high voltage for the tubes. Although many radio enthusiasts found ways to add receivers to their cars in the 1920s, it would be 1930 before Motorola made radios especially for cars in production quantities.

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Bubbles, The People-Pleasing Pandemic Panda

This year, [Thomas]’ neighborhood has gone from a quiet burg to a bustling lane full of families and children who go out walking for exercise and a change of scenery. Early on, a game emerged to distract children from the pandemic by turning these walks into bear hunts — that is, looking for stuffed bears sitting in the windows of houses and keeping count of them.

With no stuffed bears in the house, he decided to join in the fun by pasting up a 2D panda bear in the window that’s cute enough to calm anyone’s nerves. That was fun for a while, but then he turned it up to eleven by making an interactive 3D version named Bubbles the Bear that blows bubbles and speaks in a friendly voice.

Bubbles sits in a second-story window and waits for passers-by to press one of the buttons mounted on the utility pole below. Both buttons are wired to a 433MHz remote that sends a signal to an ESP32 in Bubbles’ habitat that says it’s time to perform.

We particularly like the bubble maker that [Thomas] designed, which aims a blower fan with an air concentrator at a carousel of 3D printed bubble wands. Both the fan and the carousel can be controlled with a custom web app, and he gets an email every time Bubbles has a visitor that tells him how much bubble liquid is left. Check out the fun-size demo after the break.

Bubbles are fun, especially if you can make them in extremely large quantities. Bubbles can also do work — remember this next time you need a random number generator.

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An Off-The-Grid Instant Messaging Plattform

Having an open-source communication device that is independent of any network and works without fees sounds like a hacker’s dream come true. Well, this is exactly what [bobricius]’ is aiming at with his Armawatch and Armachat devices.

Recently, [bobricius] built a LoRa based instant messaging device named Armachat. The gadget is controlled by a SAMD21 MCU with native USB and includes a QWERTY keyboard and an LCD display. Communication is based on an RFM95 LoRa transceiver which can reach a range of up to 2 km under ideal conditions. [bobricius] is a wiz when it comes to PCB design and one thing that makes his projects look so good is how he often uses PCBs as enclosures.

Armachat came in two form factors a large desktop and a smaller pocket version. The new Armawatch is another downsized version that perfectly fits on your arm by using a smaller display and keyboard. [bobricius] also did a lot of work on the firmware which now features a message delivery confirmation and the possibility to automatically resend undelivered messages. Future improvements will include message encryption, a store-and-forward function, and GPS position parsing. [bobricius] is also working on completing his portfolio of communicators with a credit-card-sized version.

LoRa is the go-to technology for off-the-grid communication devices and there are already other ongoing projects for using it to construct a mesh network.

OTA ESP32 GUI Makes Updates Simple

One of the disadvantages of having cheap WiFi-capable boards like those based on the ESP32 is that you have to update them. If you have even a few in every room of your house, it can be a pain to pull them out and connect them to a cable for programming. Over the air programming is a great answer, and [Kevin] shows how you can control the update via a simple GUI. You can see a video demonstration of how it works below.

[Kevin] uses a ready-made OTA library to do the work, but creates a GUI configuration and downloader tool. There is a manual step to force the board into the OTA mode, which might be a mild inconvenience, but it improves security since you need physical access to the device to do an update.

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WiFi Networks Turned Targets In This Pocket Game

Looking for a way to make his warwalking sessions a bit more interactive, [Roni Bandini] has come up with an interesting way to gamify the discovery of new WiFi networks. Using a Heltec WiFi Kit 8, which integrates an OLED screen and ESP8266, this pocket-sized device picks up wireless networks and uses their signal strength and encryption type as elements of the game.

After selecting which network they want to play against, a target is placed on the screen. The distance between the target and the player is determined by signal strength, and how much damage the target can take correlates to how strong its encryption is. As you can see in the video after the break, gameplay is a bit reminiscent of Scorched Earth, where the player needs to adjust the angle of their artillery to hit distant targets.

The Heltec board is attached to a 3D printed front panel, which fits neatly into an Altoids tin. The controls consist of a button and a potentiometer, and with the addition of a battery pack salvaged from an old cell phone, this little device is ready to do battle wherever you roam.

While this is just a fun diversion for the time being, [Roni] says it wouldn’t take much to actual log networks to a file and generate some statistics about their strength and encryption type. If the idea of a portable WiFi scanning companion seems interesting, you should definitely check out the Pwnagotchi project.

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Great Badge Concept: A “Geiger Counter” For WiFi Deauthentication Frames

[Nick Price] had a wonderful concept for a DEFCON badge: a device that worked a lot like a directional Geiger counter, but chirped at detecting WiFi deauthentication packets instead of radiation. That’s a wild idea and it somehow slipped past us last year. Why detect such a thing? Well, the WiFi deauth attack is a kind of invisible toxicity, effectively jamming wireless communications by forcing users to be constantly tied up with authentication, and this device would detect it.

A few things were harder than expected, however. To make the device directional, [Nick] designed and built a PCB Yagi antenna but it wasn’t practical. Not only was it far too big, it would also have required going to four layers on a PCB that was already expensive. The solution he settled on — inspired by a friend’s joke about just dropping the badge into a Pringles can — was to surround the PCB omni antenna with a copper pipe end cap from the plumbing section of any hardware store. [Nick] figured that soldering that to the ground plane should result in a simple, cheap, and attractive directional antenna mod. Did it work? We’ll all have to wait and see.

Sadly, [Nick] wasn’t able to finish in time for last year’s DEFCON. Hardware revisions mounted, and fabrication times for his specialized PCB were longer than usual. Worse news is that this year’s is cancelled, or rather is going virtual, which means he’s going to have to deauth himself. The good news is that now he’s got another 12-month extension. Watch the brief video of the functional prototype, embedded below.

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Hands On With A Batteryless E-Paper Display

E-paper displays are unusual in that power is only needed during a screen update. Once the display’s contents have been set, no power whatsoever is required to maintain the image. That’s pretty nifty. By making the display driver board communicate wirelessly over near-field communication (NFC) — which also provides a small amount of power — it is possible for this device to be both wireless and without any power source of its own. In a way, the technology required to do this has existed for some time, but the company Waveshare Electronics has recently made easy to use options available for sale. I ordered one of their 2.9 inch battery-less NFC displays to see how it acts.

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