SEN-13266
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 -200C to +700C with an accuracy of 2C while the cold junction, inside the MAX31855K, can only range from -20C to +85C while maintaining 2C 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, 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
• -200C to +700C Temperature Reading with 2C Accuracy
• 3.0V to 3.6V (+3.0V nominal) Required
• Accepts Type-K Thermocouple

Documents

• Schematic
• Eagle Files
• Hookup Guide
• Datasheet (MAX31855K)
• GitHub (Design Files)
• GitHub (Library & Example Code)