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 Arduino IDE Library Manager or as an .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 next to the lvgl 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. It also uses TFT_eSPI as 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 there are debug information inside LVGL. 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 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 log module and setting LV_LOG_LEVEL accordingly the output log is sent to the Serial port @ 115200 Baud rate.