The enclosure itself is fully DIY (I just yanked out the vape internals and glued the board edges to the vape); there’s a hole with an SMA antenna connector, visible on the photo. Plus, there are a few I2C sensors inside the vape, also glued to its inner plastic “walls”.

The hardware is partly-DIY; it’s a Meshtastic node on nRF52840 combined with HT-RA62 on a Faketec-like PCB. It runs mainline Meshtastic firmware. I originally planned to make it export its sensor and mesh data over Bluetooth (so my other stuff would ingest the data and put it into my observability pipeline), but decided against it and left this “vape” as a pure Meshtastic node that also announces its temperature, pressure and humidity. It has no screen unlike many other similar nodes.

Basically it was a fun project, and I even got a good deal on the components (it cost me like $8 total or maybe a little more).

And I also wasn’t sure of health hazards of gigahertz radio emissions in relation to cats - my design had the antenna in a VERY close proximity to the cat’s body, so that would have been yet another problem to solve…

You probably won’t believe it but I actually considered doing something like this!

The setup: I have an old Pi 3a with Alpine Linux set up; it is connected to a AR9271 USB Wi-Fi dongle running in active-monitor mode. A cheap power bank is used to, well, power the entire thing. Plus, a small 2.4 GHz antenna.

The Pi runs a custom Go app which sniffs handshakes, performs deauth and PMKID attacks, and also tries to bruteforce WPA2 (with a small password list). It also records everything and allows me to upload captured frames to the special-purpose dissector.

Finally, all of this gets put into a small bag and we’re off to, uh, “explore” the neighborhood.

I wanted to use the cat to automate the exploration, and it almost worked, except there’s an issue with the powering: Pi + dongle eat too much power, and my power bank is heavy and hazardous, so I decided against putting it in a cat “harness”. The cat itself can easily carry the board and the dongle, but having to carry a power bank would be too much for the cat.

The second cat-related issue is that people do not generally trust a cat with a 2.4 GHz antenna poking out of its harness, especially if some wiring is visible, and I didn’t want to bring negative “publicity” to the cat…

So uh, yeah, the idea was sound on paper, but cat-ifying the Wi-Fi setup had to be shelved, unfortunately.