zephyr/samples/subsys/display/lvgl
Gerard Marull-Paretas 79e6b0e0f6 includes: prefer <zephyr/kernel.h> over <zephyr/zephyr.h>
As of today <zephyr/zephyr.h> is 100% equivalent to <zephyr/kernel.h>.
This patch proposes to then include <zephyr/kernel.h> instead of
<zephyr/zephyr.h> since it is more clear that you are including the
Kernel APIs and (probably) nothing else. <zephyr/zephyr.h> sounds like a
catch-all header that may be confusing. Most applications need to
include a bunch of other things to compile, e.g. driver headers or
subsystem headers like BT, logging, etc.

The idea of a catch-all header in Zephyr is probably not feasible
anyway. Reason is that Zephyr is not a library, like it could be for
example `libpython`. Zephyr provides many utilities nowadays: a kernel,
drivers, subsystems, etc and things will likely grow. A catch-all header
would be massive, difficult to keep up-to-date. It is also likely that
an application will only build a small subset. Note that subsystem-level
headers may use a catch-all approach to make things easier, though.

NOTE: This patch is **NOT** removing the header, just removing its usage
in-tree. I'd advocate for its deprecation (add a #warning on it), but I
understand many people will have concerns.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
2022-09-05 16:31:47 +02:00
..
boards
src includes: prefer <zephyr/kernel.h> over <zephyr/zephyr.h> 2022-09-05 16:31:47 +02:00
CMakeLists.txt
README.rst
prj.conf
sample.yaml

README.rst

.. _lvgl-sample:

LittlevGL Basic Sample
######################

Overview
********

This sample application displays "Hello World" in the center of the screen
and a counter at the bottom which increments every second. If an input driver
is supported, such as the touch panel controller on mimxrt10{50,60,64}_evk
boards, "Hello World" is enclosed in a button that changes to the toggled state
when touched.

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

Display shield and a board which provides a configuration
for Arduino connectors, for example:

- :ref:`adafruit_2_8_tft_touch_v2` and :ref:`nrf52840dk_nrf52840`
- :ref:`buydisplay_2_8_tft_touch_arduino` and :ref:`nrf52840dk_nrf52840`
- :ref:`ssd1306_128_shield` and :ref:`frdm_k64f`

or a board with an integrated display:

- :ref:`esp_wrover_kit`

or a simulated display environment in a native Posix application:

- :ref:`native_posix`
- `SDL2`_

or

- :ref:`mimxrt1050_evk`
- `RK043FN02H-CT`_

or

- :ref:`mimxrt1060_evk`
- `RK043FN02H-CT`_

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

Example building for :ref:`nrf52840dk_nrf52840`:

.. zephyr-app-commands::
   :zephyr-app: samples/subsys/display/lvgl
   :board: nrf52840dk_nrf52840
   :shield: adafruit_2_8_tft_touch_v2
   :goals: build flash

Example building for :ref:`native_posix`:

.. zephyr-app-commands::
   :zephyr-app: samples/subsys/display/lvgl
   :board: native_posix
   :goals: build run

Alternatively, if building from a 64-bit host machine, the previous target
board argument may also be replaced by ``native_posix_64``.

References
**********

.. target-notes::

.. _LittlevGL Web Page: https://littlevgl.com/
.. _SDL2: https://www.libsdl.org
.. _RK043FN02H-CT: https://www.nxp.com/products/processors-and-microcontrollers/arm-based-processors-and-mcus/i.mx-applications-processors/i.mx-rt-series/4.3-lcd-panel:RK043FN02H-CT