I read updating the firmware, section A.6 and there is nothing strange in /etc/modules
$ cat /etc/modules
# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.
i2c-dev
$ uname -a
Linux sprinkler01 4.19.57-v7+ #1244 SMP Thu Jul 4 18:45:25 BST 2019 armv7l GNU/Linux
Still no watering 🙁
There is water in the lines. If you manually twist the valve, the zones water. But there is no electrical control via OSPi.