On the electronic front I have done a few more things.
Designed, built and tested the Arduino interface for the electric gate valves for my holding tanks using a relay board to create the reverse polarity switch for the motor wires. Works well including a reed switch telling me via a digital input that the gate is actually open.

Above image shows the gate valve with the reed switch, currently just taped to the body. Will glue it though.
below is a schematic of the wiring for the gate valve and the picture below that shows the actual relay board.

motorised_gatevalve_bb4relay_connected