I found the post about the uln2803a@LionHeart2017
@Diamond1 has a guide thru the first 2-6 pages of his thread. This is prob the most current and information available as we were discussing this at that time with him..
Good Luck
https://www.reef2reef.com/index.php?posts/5281522
I'm still confused as it says the 5v relay power is not shared between relay and uln2803a but the picture shows a connected com pin to the 5v power source to the relay.
This confuses me
