[mircemk] shows how to create a simple non-contact proximity sensor using little more than an Arduino Nano board ... The sensor also detects liquid water with similar ease, either in the form ...

There is no single parameter that determines the quality of a water sample, so the pollution monitor has no less than five different sensors ... network runs on an Arduino MKR GSM 1400 module.

Here is a list of projects that you can do with an Arduino that are fun ... All it requires is a moisture sensor, a water pump, and some sort of container to hold a reserve.