How did you do this?
I’m on an earlier version of the OSPi board (1.2?). With that board all the gpio pins are accessible. There is a two wire cable that goes from the GPIO (board pins 2 – 6 I think) to the OpenSprinkler board. Disconnecting this cable cuts the power to the RaspPi so you just connect a MicroUSB cable to it and power it that way.
Unfortunately, the newer boards flip the RaspPi over and all of the GPIO pins are plugged directly into the Opensprinkler board. I don’t have access to a newer board, but I think they don’t give you access to the 5v pin anymore. One workaround would be to disconnect the RaspPi, flip it back over, and use jumper cables to connect it to the Opensprinkler board.I think you would only need to jumper the odd pins from 1 through 15. The even pins are only used to power the pi on my board.
I’ll try to post some pics tonight.