It would be nice to have this feature. Right now the rain sensor prevents program from running when is activated. But… when the program is already running and the rain sensor gets activated the program is still executed, and the lawn/garden is watered during rain. Would be nice if it had an option to stop all programms when activated.
The firmware already does this. Handling of rain sensor is in a function called process_dynamic_event, it applies to all programs regardless of whether it’s a program that just started or a program that has started for some time: https://github.com/OpenSprinkler/OpenSprinkler-Firmware/blob/master/main.cpp#L1200
However, it will be ignored if the program is a manually started program (i.e. not a program that automatically started by its start time), and it will be ignored for zones that are set to ‘Ignore Sensor’.