A couple of suggestions: 1) try to restart the OpenSprinkler firmware (sudo /etc/init.d/OpenSprinkler.sh restart) and see if it makes any difference. The firmware is on port 8080 (unless if you accidentally changed the port). 2) do you happen to have a WiFi USB dongle? You can get your RPi online through WiFi and see if it works.
Although the programs are all stored in a local file (called nvm.dat), it’s in binary form and you can’t easily edit it.