Thermocouples are very sensitive, requiring a good amplifier with a cold-compensation reference. There are lots of breakout boards that carry MAX31855 which is an SPI interface thermocouple amplifier. MAX31855 is great, but when there are lots of thermocouples to measure, it is not easy to use. The new MAX31850 is being carried by Thermocouple Amplifier with 1-Wire Breakout Board - MAX31850K because it is a “1-Wire” thermocouple amp which can have any number of breakouts on a single shared I/O line.
The MAX31850K does everything for you, and can be easily interfaced with any microcontroller that has 1-Wire support. Thermocouple Amplifier with 1-Wire Breakout Board - MAX31850K has the chip itself, a 3.3V regulator with 10uF bypass capacitors all assembled and tested. This board can be used with 'parasitic power' - where the power is on the data line - or with 'local power' where the power for the converter comes in on the Vin Pin.
The MAX31850K data format is very similar to that of the well known 1-Wire DS18B20 temp sensor but it is not drop in compatible without code changes to check for the new '1 Wire family' type. Adafruit has adapted the classic Arduino OneWire and DallasTemp libraries to be MAX31850 compatible, so you can check Adafruit libraries using the links in the Documents section.
Thermocouple Amplifier with 1-Wire Breakout Board - MAX31850K comes with a 2 pin terminal block (for connecting to the thermocouple), 4.7K data line pullup resistor, and pin header (to plug into any breadboard or perfboard). The breakout board can only be used with K-type thermocouples.
Please note: Thermocouple Amplifier with 1-Wire Breakout Board - MAX31850K does not have level shifting on the 3V Data line. This is done on purpose so that it can be used in parasitic mode. The data line must be level shifted to 3V. 4-Channel I2C-safe Bi-Directional Logic Level Converter is a good choice for level shifting 1-Wire. The great part is you only need one level shifter at the 1-Wire host for all thermocouples on the shared data line.
OneWire Library Adaptation by Adafruit: https://github.com/adafruit/MAX31850_OneWire
DallasTemp Library Adaptation by Adafruit: https://github.com/adafruit/MAX31850_DallasTemp
Adafruit Web Site: https://www.adafruit.com/product/1727