Currently I have it only to usb and not wired up to anything, i believe that the usb supplies 5v but could be wrong. I do also have a power shield and the device reacts the same when hooked up to that.
I dont have a full circuit diagram at the ready but i can tell you that i have 7 of the circuit found in the link below as well as some simple circuits for sensors, dsb1820, a few float valves, etc.
Here is the like referenced above
I have tried almost everything i could find on the forum to no avail.
Thanks