Thermocouple Breakout - MAX31855K

The SparkFun MAX31855K Thermocouple Breakout is a simple 14-bit resolution, SPI-compatible, serial interface thermocouple digitizer that makes reading a wide range of temperatures possible. A thermocouple works by taking two wires made of dissimilar metals, connecting them at the two ends, and making a temperature gradient between one end and the other (a 'hot' end and a 'cold' one). Once this is achieved, a voltage potential is formed and current flows. The SparkFun Thermocouple Breakout takes a standard Type-K thermocouple in one end, digitizes the temperature measured and sends that data out the other end via a SPI interface, thereby interpreting the data and translating it for you to read!

With the SparkFun Thermocouple Breakout, the thermocouples hot junction can be read from -200°C to +700°C with an accuracy of ±2°C while the cold junction, inside the MAX31855K, can only range from -20°C to +85°C while maintaining ±2°C accuracy. The MAX31855K constantly measures the temperature of the cold junction using an internal temperature-sensing diode. The MAX31855K requires a power source from +3.0V to +3.6V (+3.0V nominal) and only draws 1.5mA maximum.

The Thermocouple Breakout is designed to accept a standard [thermocouple connector](https://www.sparkfun.com/products/13612), for convenience and compatibility with probes you may already own. These connectors arent necessary, and you could solder a thermocouple directly into the through-holes labeled ˜+ and ˜-. If you decide to solder the thermocouple directly to the breakout board, it is recommended that the thermocouple be mounted for strain relief to avoid breaking the thin wires. Notches for a zip-tie or wire wrapping have been provided in the PCB opposite the header for this purpose.

**Features:**

* 14-bit Resolution
* SPI-Compatible, Serial Interface
* -200°C to +700°C Temperature Reading with ±2°C Accuracy
* 3.0V to 3.6V (+3.0V nominal) Required
* Accepts Type-K Thermocouple

**Documents:**

* [Schematic](https://cdn.sparkfun.com/datasheets/Sensors/Temp/SparkFun_Thermocouple_Breakout_v10.pdf)
* [Eagle Files](https://cdn.sparkfun.com/datasheets/Sensors/Temp/SparkFun_Thermocouple_Breakout_v10.zip)
* [Hookup Guide](https://learn.sparkfun.com/tutorials/max31855k-thermocouple-breakout-hookup-guide)
* [Datasheet](https://cdn.sparkfun.com/datasheets/Sensors/Temp/MAX31855K.pdf) (MAX31855K)
* [GitHub](https://github.com/sparkfun/MAX31855K_Thermocouple_Breakout) (Design Files)
* [GitHub](https://github.com/sparkfun/SparkFun_MAX31855K_Thermocouple_Breakout_Arduino_Library) (Library & Example Code)

**Videos**