My first full hardware prototype, the CC1101 Adapter for the Lilygo T-LoRa Pager, is still in development as WX-1D (Wrewtopia labs eXperimental unit 1, revision 4), and is undergoing testing right now. While that's been further along in development I've been working on a completely new project with a completely custom hardware design.
The Idea
The main idea driving this was an extension of the work I've done on a lot of firmware that adds the ability to detect surveillance devices nearby - like Flock Safety cameras, Ring Doorbells, Drones, and other widespread mass surveillance technology. It's a good start to know that these things are present, but it doesn't necessarily help you if you don't know WHERE they are. I wanted a device that could do both - and show you on a nice sized screen.
The Design
I wanted to use low cost hardware wherever possible - so I designed it around the ESP32-S3 MCU, and readily available low cost components. The most expensive component is the IMU (think of it as a smart motion sensor), but that couldn't be helped.
The design itself is relatively simple - use an ESP32S3 combined with a display and a discrete built in directional antenna coupled with an IMU to be able to tell you the cardinal direction from you that an emitting device is.
I opted for built in poured copper directional patch antenna and a poured copper omni antenna as well, built into their own daughter board. This was the most time consuming part of the build because I had to run simulations on the antenna geometry to make sure it would resonate at the right frequency bands I'm targeting (2.4 ghz range). The rest was your typical PCB component placement and routing, which isn't HARD but can be tedious and time consuming.
RESULT
I'm waiting for manufacturing the come back with the completed boards, but.... the renderings look damn cool and make me super excited to get my hands on them.