Sorry, I was referring to decoupling caps
As you can see, data should only be coming from one MAX31855 at a time, but when analyzing the circuit I was seeing signals from, say, CH2 when executing getTemp(CH1)!
So the data should only be coming from one chip at a time. I call getTemp(*) for CH1-CH9 in order, and since the Chip Select (CS) pins for each chip come from a separate pin on the Uno, I should be able to call for data from each chip individually. If I call getTemp(CH1), the CS pin for chip 1 receives a signal, sending temperature data to the SO data bus. During this loop, any data that comes to the Uno should only be from that chip. Does that make sense?
As for the decoupling caps, I initially thought the same thing as you, but I based my design on the other *.brd file in my first post. I also emailed Ryan Mclaughlin, who has designed breakout boards for the MAX chips, and made sure I wasn't missing a connection to ground. He said I wasn't. Do you think he is incorrect? Thanks.