OpenSprinkler › Forums › Hardware Questions › OpenSprinkler Pi (OSPi) › Cheap Sprinkly Pi › Re: Re: Cheap Sprinkly Pi May 6, 2013 at 4:41 am #23605 RayKeymaster If you don’t need 24VAC->5VDC conversion, and you don’t need RTC, then you can get the OpenSprinkler Zone Expansion Board, which requires a minimum of 6 pins (3.3V, GND, and four shift register pins) to interface with Pi.
