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 thermocoupleâ€™s hot junction can be read from -200آ°C to +700آ°C with an accuracy of آ±2آ°C while the cold junction, inside the MAX31855K, can only range from -20آ°C to +85آ°C while maintaining آ±2آ°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 arenâ€™t necessary, and you could solder a thermocouple directly into the through-holes labeled â€ک+â€™ and â€ک-â€™. 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.
* 14-bit Resolution
* SPI-Compatible, Serial Interface
* -200آ°C to +700آ°C Temperature Reading with آ±2آ°C Accuracy
* 3.0V to 3.6V (+3.0V nominal) Required
* Accepts Type-K Thermocouple
* [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)