Well, I got the quad Max31856 boards yesterday. I quickly hooked them up to my spare Mega, and they work as they should.. I've only started with 1 chip, but it works well.. Trying to figure out how to connect it to my blackbox without turning it into a ratsnest... it's already pretty bad, I'm using a LOT of the pins of the Mega already
sweet i'm hoping to be down to wiring in a month or 2. So I'm still waiting to order mine.
It's a 19 bit ADC in it.. works out to about .01F increments. Celsius/Fahrenheit conversion is done in library. found someone else's review and they dipped the thermocouple in liquid nitrogen, and it was about 2*F off, part of that could have been from difference in atmospheric pressure though. It's plenty accurate enough for EGT's anyhow!
don't get much colder then that. for me I think the max31856 is over kill.
It does temperature averaging over several samples if you want it to.. I don't think I'll regret it.. it also can handle about 7 different types of thermocouples, which is a nice option