After a few setbacks and trying out various combinations of components, I finally have all 16 pumps being controlled from this Arduino! I ended up getting a new Arduino that has enough pins to drive the relays directly instead of going through a serial expander board which was causing me problems. I also abandoned the Darlington arrays in favor of these relay boards that have all the relay isolation stuff done for me. This also keeps the 5v Arduino and 12v pump power supplies completely separate, which I feel much more comfortable about. Next step is to mount this into my cabinet and hook up the tubing! Then time to get to work on the recipe database! #barbot
I have used those relay boards in several projects. They're well worth the extra few bucks. The first big control project I did, I soldered my own relay board together...turned into a huge pita (it does still work though). Looking forward to seeing the finished project.