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Arduino library for using the Maxim Integrated MAX31855 cold-junction compensated thermocouple to digital sensor.
The MAX31855 comes in a small SOIC package, but is also available as a breakout board. The Digilent Pmod TC1 is a 3.3V version, while the Adafruit MAX31855 breakout is 5V compatible.
The MAX31855 uses SPI and, when selected, sends a 4 byte buffer which can be decoded to show faults, the ambient die-temperature (cold-junction) and the thermocouple temperature. It does not have any settings or data input, making the library simple. Temperatures are returned in degrees Celsius and the accuracy of the thermocouple temperature is ±0.2°C over a range from -200°C to 700°C depending on the thermocouple type. The K-Type thermocouple used for developing this library gives a range of -73°C to 482°C. The ambient temperature reading is affected by die and PCB temperature and will generally be above actual ambient room temperature.
