Is it possible to control the OSPi v1.2 with just an Arduino?
I found the Raspberry Pi + Wifi connectivity unreliable and have good experience with Arduino + RF modules. So instead of buying a new Arduino based OpenSprinkler I would like to “convert” my OPSi to control it with an Arduino.
It’s possible but will be a lot of work. The OSPi schematic is all available in Github. But before you start, have you tried to use wired Ethernet with RPi, which is generally more reliable than WiFi?