zephyr

History

Keith Packard 0b90fd5adf samples, tests, boards: Switch main return type from void to int As both C and C++ standards require applications running under an OS to return 'int', adapt that for Zephyr to align with those standard. This also eliminates errors when building with clang when not using -ffreestanding, and reduces the need for compiler flags to silence warnings for both clang and gcc. Most of these changes were automated using coccinelle with the following script: @@ @@ - void + int main(...) { ... - return; + return 0; ... } Approximately 40 files had to be edited by hand as coccinelle was unable to fix them. Signed-off-by: Keith Packard <keithp@keithp.com>		2023-04-14 07:49:41 +09:00
..
boards	…
src	…
CMakeLists.txt	…
README.rst	…
prj.conf	…
sample.yaml	…

README.rst

MAX6675 K-thermocouple to digital converter
###########################################

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>