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, you ...

The ESP32 is a beloved microcontroller from Espressif, offering quite a lot in a small, very cheap package. Yet as you may already know, there are lots of different kinds of ESP32, and it can be hard ...