Question
MAX31856 is going to be used as an 8 channel datalogger. The MCU doesn't have many pins. Can the FAULT and DRDY pins of the MAX31856 be left floated?
Answer
The FAULT and DRDY pins are outputs only and their main purpose is just to inform the user that there is a fault occurs and a conversion is complete. You can leave these pins floating. There shouldn't be any issues with that.