I have a design of 3 addon boards for a Rasperry Pi (see attached files):1. to control up to 4 valves in 6VDC; 12VDC or 24VDC (voltage set by software - rasperry pi)2. to control one pump in voltage of 3VDC, 6VDC, 12VDC or 24VDC (voltage set by jumper)3. to control one stepper motor driven pumpDesig