Thermocouples are very sensitive, requiring a good amplifier with a cold-compensation reference. The MAX31855K does everything for you and can be easily interfaced with any microcontroller, even one without an analog input.
3.3 to 5v power supply and logic level compliant
Works with any K type thermocouple
Will not work with any other kind of thermocouple other than K type
Working temperature: -20 ℃ ～ 85 ℃
Working voltage: 3.0 ~ 5.5V; working current: 50mA