I am developing an automation system that requires the use of a PiFace2 Digital board and a DS18B20 temperature sensor, as the PiFace 2 does not allow access to the IO pins I am also using a PiFace IO Shim. I have C code that interacts with both the sensor and PIFace2 and works correctly when each item is connected to the Pi individually. However when I connect the DS18B20 to the Pi using the IO shim I am unable to read the temperatures. The C code returns garbage! I have checked the voltage across IO pins 1 and 6 on the shim and am getting 3.3V so it appears that the shim is connected correctly!
Is it possible to use the PiFace 2 and the one wire interface simultaneously?