So I have received my boards and assembled one.
Preliminary testing at the moment and it’s working great.
The Boost circuit produces about 22.5v.
My software modifications are working great, see fork link above.
Tested with some solenoids and they open and stay open OK with no water pressure.
However when there is water pressure they open OK, but then close almost immediately (after the booster is turned off).
Seems the 5V is not sufficient to keep them open.
I’m using the below 12V DC solenoids
Ray does the OpenSprinker DC drive the solenoids OK when run from 5V eg USB?
Solved my issues:
There was too much resistance in the cable from the OSPi Mini to Solenoids (10m run), resulting inadequate current to hold it open.
Fix: Doubled the conductors and she working like it should!