init Files

libraries/lvgl/docs/integration/framework/arduino.rst

@@ -0,0 +1,103 @@
+=======
+Arduino
+=======
+
+The `LVGL library <https://github.com/lvgl/lvgl>`__ is directly available as Arduino libraries.
+
+Note that you need to choose a board powerful enough to run LVGL and
+your GUI. See the `requirements of LVGL <https://docs.lvgl.io/master/intro/index.html#requirements>`__.
+
+For example ESP32 is a good candidate to create UI's with LVGL.
+
+Get the LVGL Arduino library
+----------------------------
+
+LVGL can be installed via the Arduino IDE Library Manager or as a .ZIP library.
+
+You can `Download <https://github.com/lvgl/lvgl/archive/refs/heads/master.zip>`__
+the latest version of LVGL from GitHub and simply copy it to Arduino's
+library folder.
+
+Set up drivers
+--------------
+
+To get started it's recommended to use `TFT_eSPI <https://github.com/Bodmer/TFT_eSPI>`__ library as a TFT
+driver to simplify testing. To make it work, setup ``TFT_eSPI``
+according to your TFT display type via editing either:
+
+- ``User_Setup.h``
+- or by selecting a configuration in the ``User_Setup_Select.h``
+
+Both files are located in ``TFT_eSPI`` library's folder.
+
+
+Configure LVGL
+--------------
+
+LVGL has its own configuration file called ``lv_conf.h``. When LVGL is
+installed, follow these configuration steps:
+
+1. Go to the directory of the installed Arduino libraries
+2. Go to ``lvgl`` and copy ``lv_conf_template.h`` as ``lv_conf.h`` into the Arduino Libraries directory next to the ``lvgl`` library folder.
+3. Open ``lv_conf.h`` and change the first ``#if 0`` to ``#if 1`` to enable the content of the file
+4. Set the color depth of you display in :c:macro:`LV_COLOR_DEPTH`
+
+Finally the layout with ``lv_conf.h`` should look like this:
+
+::
+
+   arduino
+    |-libraries
+      |-lvgl
+      |-other_lib_1
+      |-other_lib_2
+      |-lv_conf.h
+
+
+Initialize and run LVGL
+-----------------------
+
+Take a look at `LVGL_Arduino.ino <https://github.com/lvgl/lvgl/blob/master/examples/arduino/LVGL_Arduino/LVGL_Arduino.ino>`__
+to see how to initialize LVGL. ``TFT_eSPI`` is used as the display driver.
+
+In the INO file you can see how to register a display and a touchpad for
+LVGL and call an example.
+
+
+Use the examples and demos
+--------------------------
+
+Note that, there is no dedicated INO file for every example. Instead,
+you can load an example by calling an ``lv_example_...`` function. For
+example :cpp:func:`lv_example_btn_1`.
+
+:important: Due to some the limitations of Arduino's build system you
+            need to copy ``lvgl/examples`` to ``lvgl/src/examples``. Similarly for
+            the demos ``lvgl/demos`` to ``lvgl/src/demos``.
+
+
+Debugging and logging
+---------------------
+
+LVGL can display debug information in case of trouble. In the
+``LVGL_Arduino.ino`` example there is a ``my_print`` method, which sends
+this debug information to the serial interface. To enable this feature
+you have to edit the ``lv_conf.h`` file and enable logging in the
+section ``log settings``:
+
+.. code:: c
+
+   /*Log settings*/
+   #define USE_LV_LOG      1   /*Enable/disable the log module*/
+   #if LV_USE_LOG
+   /* How important log should be added:
+    * LV_LOG_LEVEL_TRACE       A lot of logs to give detailed information
+    * LV_LOG_LEVEL_INFO        Log important events
+    * LV_LOG_LEVEL_WARN        Log if something unwanted happened but didn't cause a problem
+    * LV_LOG_LEVEL_ERROR       Only critical issue, when the system may fail
+    * LV_LOG_LEVEL_NONE        Do not log anything
+    */
+   #  define LV_LOG_LEVEL    LV_LOG_LEVEL_WARN
+
+After enabling the log module and setting :c:macro:`LV_LOG_LEVEL` accordingly, the
+output log is sent to the ``Serial`` port @ 115200 bps.