The Sprinkler controller was designed to act as a interface and controller for managing sprinkler system valves (also called zones). Those that exist either use what I consider to be unreliable protocols (X10), have a very limited number of valves (like 6 or 8), aren’t opto-isolated (i.e. just relays, pratically guaranteed to send huge transients into your automation system) or are just expensive (like $250 for 8 zones).
Currently i don’t have a lawn so I’m not too interested in this kind of projects, but i thought you might be.
27 Zone Sprinkler Controller With Pump Control: [Link]