Forgive me for more OT posts. I'm pretty weak on EE work. And I'm getting good advice here. So there will be a lot of queries on my high tunnel ventilation project.
I ordered this board to deal with my IO shortage:
This works and I'm moving on. But its a kludge - Module to expander to relay pair. VS just a brain attached to an Opto22 board and use four outs for up and down.
I got the same query on how to direct the IO group to which one of the four motors. The plan here is to have four outs that turn on all the IO for motors one, two, three, or four. (each motor has power up, power down, upper limit, lower limit, rotation counter) Only deal with one motor at a time. I always think in terms of sourcing - turn the power on to the group I'm using. With sinking only outs, I'll have 12 volt everywhere and only ground the group I'm using. Is this a problem? I don't feel comfortable with it. Should I also have four ice cube relays to direct power to the right motor? Again, this will work but its a total kludge.
You guys are going to start thinking I'm just like that "Stryped" fella building his garage.