Well, I guess I should read the DMS boards before embarking on new projects. My existing irrigation controller went south and I picked up a RPi A+ and a $10 relay board for replacement duty.
See this thread for relay
My plan is to use one of the Weather APIs to determine if the system should water or hold off in anticipation of rain, and then check if it actually rained the previous day. I have java/groovy background, so I’m using pi4j.
Initially, the watering schedule will be driven off a config file, updated via SSH. Once everything’s rolling, I’ll think about a more sophisticated UI. With the UI comes the choice of either running a web server on the RPi (and attendant security considerations) or hosting the config file on one of my remote web servers and having the RPi operate as a http client only.