“can I use the RASPi that my OSPi is sitting on for other programming, or does OSPI need the whole Pi?” — yes, RPi has plenty of computation power so you can use it for other tasks simultaneously. The only restriction is just whatever other services you are running should not occupy the same HTTP port as the OpenSprinkler firmware.
Now I know I’m going to have to figure this out for myself, but (being a novice) would you let me know if I’m heading in the right direction?
It looks like to me that I’m going to have to log into the RPi and add a port for it communicate from on the WiFi. I will then be able to add programming to the RPi that will run simultaneously with my OSPi. Any links or comments would be appreciated.
You can program other web services and run them on RPi, as long as they use a different port than what OpenSprinkler firmware uses (the default is 8080 unless if you have changed it). For example, some users use the same RPi to host the weather service and use port 80 for that. You can pretty much use any programming language of your choice to write a web service, and run it on RPi. Python is pretty popular, and there are tons of other choices too, like nodejs.