@dan: cool, thanks for releasing the new plugin architecture!
my first station kicks on automatically; I presume this is when the interval program is starting up.
Does the station kick on even when no program is running? If it stays on that’s unusual.
I’ve noticed that on OSBo during system reboot the valves will pop very momentarily. I have yet to investigate what caused this. It’s known that 74HC595 shift register initializes to undefined states, that’s why there is an output enable (OE) signal line which controls when the output from the shift register will become ‘visible’. Before the OE pin is pulled low, all outputs are disabled (i.e. high impedance state). That’s why upon reset, all valves will be released, and no valve will be activated until the software pulls the OE pin low.
On the microcontroller-based OpenSprinkler, the shift register gets refreshed every second (by calling the apply_station_bits function). I assume this is the same in the Python program. If this is the case (and station_bits are all initialized to 0 at the beginning), it should turn off all valves when the program starts running. Dan can probably confirm this.