Continuing the discussion from Ask a littleBits engineer:
if you run a blank sketch on the arduino the arduino pins default to INPUT. if you hook the bargraph or the number module to the output of d5 or d9, you will see there is about 1.1v on the pins. It doesn’t really matter if the d5/d9 switches are in ANALOG or PWM. Looking at the schematic, presumably this voltage is related to the opamp/RC stuff on the module for d5 and d9. I’m curious why this is 1.1v?
(of course, if you set d5/d9 to OUTPUT, then you will have 0 volts on those pins)