zephyr/samples/sensor/max6675

.. zephyr:code-sample:: max6675
   :name: MAX6675 K-thermocouple to digital converter
   :relevant-api: sensor_interface

   Get temperature from a MAX6675 K-thermocouple to digital converter (polling
   mode).

Overview
********

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

Requirements
************

- MAX6675 wired to your board SPI bus
- K-thermocouple connected to MAX6675 T+/T- inputs

References
**********

 - MAX6675: https://datasheets.maximintegrated.com/en/ds/MAX6675.pdf

Building and Running
********************

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

.. zephyr-app-commands::
   :zephyr-app: samples/sensor/max6675
   :board: nucleo_f030r8
   :goals: build
   :compact:

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.

.. code-block:: console

   Temperature: 25.25 C
   Temperature: 25.50 C

   <repeats endlessly every second>