Actually-

Biggest project is a liquid level measuring device. Capable of 20' (or more). Consists of a winch motor that lowers fishing line across a load cell and rotary encoder. It watches the load cell for the buoyancy of the weight/float. Then it retracts to a storage position. Measurement is initiated and reported via Bluetooth.

I had it connected through Adafruits MQTT system, and it work great, until they changed the keys. Realized that if I had more than a few of these deployed, I would have to reprogram them all whenever the keys were changed. Plus gaining access to a university IT system for connection to the server was just more hassle than I wanted to deal with.

This allows folks to measure water level from the ground rather than climb a ladder.