zephyr/samples/sensor/max30101
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

.. _max30101:

MAX30101 Heart Rate Sensor
##########################

Overview
********

A sensor application that demonstrates how to poll data from the max30101 heart
rate sensor.

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

This project configures the max30101 sensor on the :ref:`hexiwear_k64` board to
enable the green LED and measure the reflected light with a photodiode. The raw
ADC data prints to the console. Further processing (not included in this
sample) is required to extract a heart rate signal from the light measurement.

.. zephyr-app-commands::
   :zephyr-app: samples/sensor/max30101
   :board: hexiwear_k64
   :goals: build
   :compact:

Sample Output
=============

.. code-block:: console

   GREEN=5731
   GREEN=5750
   GREEN=5748
   GREEN=5741
   GREEN=5735
   GREEN=5737
   GREEN=5736
   GREEN=5748

<repeats endlessly>