The ESP32 Bus Pirate project has everything you need to turn an ESP32 device into a protocol sniffing/decoding powerhouse—all on a board you may have sitting around from another project.

[Simon Monk] got frustrated with bad ADC performance when tinkering with an ESP32 board, and decided to put three of the nowadays-iconic boards to the test – a classic ESP32 devboard, a Pi Pi… ...

I've been playing around with a couple of ESP32 microcontrollers, and that experimentation has taught me a lot about sensors and what you can build for really, really cheap. For as little as $4 ...