I wonder if someone can explain why I'm reading all zeros from my un-connected inputs to my piface digital board? I'm a new user of the piface board so I'm just doing some simple python scripts like the following:
import pifacedigitalio
pfd = pifacedigitalio.PiFaceDigital()
pfd.input_port.value
pfd.input_port.value returns 0 with nothing connected to the input ports. I thought it should return 255 (all 1's) since nothing is connected, and I read that there are weak pullup resistors on the inputs. Do the pullups have to be enabled, or is there a configuration command to invert the inputs that maybe required?