Arduino

The core LVGL library and the examples are directly available as Arduino libraries.

Note that you need to choose a powerful enough board to run LVGL and your GUI. See the requirements of LVGL.

For example ESP32 is a good candidate to create your UI with LVGL.

Get the LVGL Ardunio library

LVGL can be installed via the Arduino IDE Library Manager or as a .ZIP library. It will also install lv_exmaples which contains a lot of examples and demos to try LVGL.

Set up drivers

To get started it's recommended to use 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 the followings needs to be done to configure it:

  1. Go to 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

  4. Set the resolution of your display in LV_HOR_RES_MAX and LV_VER_RES_MAX

  5. Set the color depth of you display in LV_COLOR_DEPTH

  6. Set LV_TICK_CUSTOM 1

Configure the examples

lv_examples can be configures similarly to LVGL but it's configuration file is called lv_ex_conf.h.

  1. Go to directory of the installed Arduino libraries

  2. Go to lv_examples and copy lv_ex_template.h as lv_ex_conf.h next to the lv_examples folder.

  3. Open lv_ex_conf.h and change the first #if 0 to #if 1

  4. Enable the demos you want to use. (The small examples starting with lv_ex_...() are always enabled.)

Initialize LVGL and run an example

Take a look at 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 touch pad for LVGL and call an example.

Note that, there is no dedicated INO file for every example but you can call functions like lv_ex_btn1() or lv_ex_slider1() to run an example. For the full list of examples see the README of lv_examples.

Debugging and logging

In case of trouble LVGL can display debug information. In the LVGL_Arduino.ino example there is my_print method, which allow to send this debug information to the serial interface. To enable this feature you have to edit lv_conf.h file and enable logging in the section log settings:

/*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 LV_LOG_LEVEL accordingly the output log is sent to the Serial port @ 115200 bps.