This is the documentation for the latest (master) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

MAX6675 K-thermocouple to digital converter


This is a sample application to read an external MAX6675 cold-junction-compensated K-thermocouple to digital converter.


  • MAX6675 wired to your board SPI bus

  • K-thermocouple connected to MAX6675 T+/T- inputs

Building and Running

This sample can be built with any board that supports SPI. A sample overlay is provided for the NUCLEO-F030R8 board.

west build -b nucleo_f030r8 samples/sensor/max6675

Sample Output

The application will read and print sensor temperature every second. Note that temperature fetch will fail if the K-thermocouple is not connected. This is because MAX6675 is able to detect if the K-thermocouple is connected or not.

Temperature: 25.25 C
Temperature: 25.50 C

<repeats endlessly every second>