Finished a tank sender hub and it’s documentation in my development web. Decided to use only 4 per hub. That has to do with location and number of IOs of the processor and plugs.
The hub is fairly simple, it just provides connectors for 4 tank senders and the signal wire of the sender is connected to the 7 pin plug which connects to the processor.
I also have another one wire connector which allows to connect a one wire hub for temperature sensors.
Next is the valve and sender processing unit.