Dan K. from California wrote an excellent blog post about how to set up a Raspberry Pi to work with OpenSprinkler. The link to the blog post can be found here:
http://xperimentia.com/2012/12/14/setting-up-a-raspberry-pi-to-work-with-opensprinkler/

and you can download his scripts from the OpenSprinkler GitHub repository (link given in his post). The scripts basically consist of two parts: 1) storing and serving Javascripts required by OpenSprinkler on a Pi server (recall that currently these Javascripts are served on the rayshobby.net server); 2) using Pi to log OpenSprinkler status (this part is based on Dave Gustavson’s PHP scripts). As Raspi is compact, low-cost, and low-power, it is becoming an increasingly popular embedded Linux platform. The combination of Pi with OpenSprinkler also makes it possible to develop sophisticated features in the future like weather-based irrigation control, or leaning-based control like the Nest thermostat. Perhaps it’s time for me to think about an OpenSprinkler Pi Edition 🙂