zephyr/samples/drivers/lcd_hd44780
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
..
src samples, tests, boards: Switch main return type from void to int 2023-04-14 07:49:41 +09:00
CMakeLists.txt cmake: increase minimal required version to 3.20.0 2021-08-20 09:47:34 +02:00
README.rst samples: drivers: lcd_hd44780: Add readme 2020-05-15 17:18:56 +02:00
prj.conf
sample.yaml sanitycheck: inclusive language 2020-08-27 07:04:07 -04:00

README.rst

.. _samples_lcd_hd44780:

LCD HD44780 driver sample
#########################

Overview
********
Display text strings on parallel interfacing HD44780 based
generic LCD controller using GPIO pins to interface with
Arduino Due (SAM3).

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

This project can be built and executed on as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/lcd_hd44780
   :host-os: unix
   :board: arduino_due
   :goals: flash
   :compact:

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

.. code-block:: console

    LCD Init
    Page 1: message
    Page 2: message
    Page 3: message

Display output
==============

.. code-block:: console

    ********************
    Arduino Due
    yalpsiD DCL 4x02
    ********************

.. code-block:: console

    -------------------
    Zephyr Rocks!
    My super RTOS
    -------------------

.. code-block:: console

    --------------------
    --------HOME--------
    I am home!