Another must have tinker board
I love timers. This particular timer allows a relay to stay on for a selected time. Great for tinkering and cheap too. I just ordered a couple.
These boards are great for random logic circuitry. My transducer lift is a random logic design. I made it work with relays and switches. No electronics except for the china made power supply. Today's graduate engineers would struggle to figure out how my deploy circuitry works. I love relays.
https://www.ebay.com/itm/DC-12V-Infi...UAAOSwgY9XdQwe