display_lvgl

# Display LVGL Example

- [中文版](./README_CN.md)

## Example Brief

This example demonstrates how to use the `esp_board_manager` with LVGL on supported development boards. It initializes the board manager, sets up the LVGL adapter, adds the LCD display and touch input (if available), and runs the LVGL test UI.

## Environment Setup

### Default IDF Branch

This example supports IDF release/v5.5 (>=5.5.2) and IDF release/v5.4 (>=5.4.3) branches.

### Hardware Required

- LCD
- Optional: LCD Touch, LEDC brightness control

## Build and Flash

### Build Preparation

Before building this example, make sure ESP-IDF is set up. If it is already configured, you can skip this step; otherwise, run the following scripts in the ESP-IDF root directory to set up the build environment. For the complete steps of configuring and using ESP-IDF, see the [ESP-IDF Programming Guide](https://docs.espressif.com/projects/esp-idf/en/latest/esp32s3/index.html):

```shell
./install.sh
. ./export.sh
```

This example uses [ESP Board Manager](https://github.com/espressif/esp-board-manager) to manage board-level resources. The [`esp-bmgr-assist`](https://pypi.org/project/esp-bmgr-assist/) helper tool is recommended as the default entry point.

Install it in the activated ESP-IDF Python environment (only needed once per environment):

```bash
pip install esp-bmgr-assist
pip install --upgrade esp-bmgr-assist  # run this command when an update is requested
```

- Navigate to the LVGL display example project directory:

```shell
cd $YOUR_GMF_PATH/packages/esp_board_manager/examples/display_lvgl
```

### Build and Flash Commands

- List the currently visible boards:

```bash
idf.py bmgr -l
```

Example output:

```text
ℹ️  Board Components:
  espressif/esp_boards:
    [1] esp32_c3_lyra
    [2] esp32_lyrat_4_3
    [3] esp32_lyrat_mini_1_1
    [4] esp32_p4_eye
    [5] esp32_p4_function_ev_board
    [6] esp32_s31_function_coreboard_1
    [7] esp32_s31_korvo_1
    [8] esp32_s3_box_3
    [9] esp32_s3_box_lite
    [10] esp32_s3_korvo_2_3
    [11] esp32_s3_lcd_ev_board
    [12] esp_vocat_1_0
    [13] esp_vocat_1_2
```

The example output above is based on the board list and ordering from `esp_boards` 0.5.2. Different `esp_boards` versions or custom board dependencies may change the list and indexes. Use the actual output of `idf.py bmgr -l` when selecting a board.

- Select a board:

```bash
idf.py bmgr -b <board_index|board_name>
```

For example, to select `esp32_s3_korvo_2_3`:

```bash
idf.py bmgr -b 10
# or
idf.py bmgr -b esp32_s3_korvo_2_3
```

On first invocation of `idf.py bmgr`, the component is downloaded automatically based on the `espressif/esp_board_manager` dependency declared in `main/idf_component.yml`.

> [!NOTE]
> To switch to a different board supported by `esp_board_manager`, repeat the same steps with the new board name or index.
> For a custom board, see [Creating a Board Guide](https://docs.espressif.com/projects/esp-board-manager/en/latest/create-board/index.html).
> For more information about `esp_board_manager`, see the [ESP Board Manager Getting Started Guide](https://github.com/espressif/esp-board-manager/blob/main/esp_board_manager/README.md).

- Compile the example code:

```shell
idf.py build
```

Flash the program and run the monitor tool to view serial output (replace PORT with your port name):

```shell
idf.py -p PORT flash monitor
```

To exit the monitor, use `Ctrl-]`.

## How to Use the Example

### Functionality and Usage

- After the example starts, it will automatically initialize the display and run the LVGL test UI. The output will be as follows:

```c
I (829) BMGR_DISPLAY_LVGL: Starting LVGL Example
...
I (889) DEV_DISPLAY_LCD: Initializing LCD display: display_lcd, chip: st7789, sub_type: i80
I (899) DEV_DISPLAY_LCD_SUB_I80: Initializing I80 LCD display: display_lcd, chip: st7789
I (1029) DEV_DISPLAY_LCD: Successfully initialized LCD display: display_lcd (sub_type: i80), panel: 0x3fce9f40, io: 0x3c0b09e8
I (1029) BOARD_MANAGER: Device display_lcd initialized
...
I (1049) BMGR_DISPLAY_LVGL: Initializing LVGL adapter...
I (1059) LVGL: Starting LVGL task
I (1059) BOARD_DEVICE: Device handle display_lcd found, Handle: 0x3fce9b14 TO: 0x3fce9b14
I (1069) BOARD_DEVICE: Device display_lcd config found: 0x3c0a4ba0 (size: 184)
I (1079) BMGR_DISPLAY_LVGL: Running LVGL Test UI
I (1079) lvgl_test_ui: Starting LCD LVGL test sequence
I (1089) lvgl_test_ui: Testing Magenta screen
I (1109) lvgl_test_ui: cleanup_ui_elements done
I (4219) lvgl_test_ui: cleanup_ui_elements done
I (4719) lvgl_test_ui: Testing Cyan screen
I (4719) lvgl_test_ui: cleanup_ui_elements done
I (7819) lvgl_test_ui: cleanup_ui_elements done
I (8319) lvgl_test_ui: Testing Blue screen
I (8319) lvgl_test_ui: cleanup_ui_elements done
I (11419) lvgl_test_ui: cleanup_ui_elements done
I (11919) lvgl_test_ui: Testing White screen
I (11919) lvgl_test_ui: cleanup_ui_elements done
I (15019) lvgl_test_ui: cleanup_ui_elements done
I (15519) lvgl_test_ui: show_test_results start
I (15519) lvgl_test_ui: show_test_results UI update done
I (18519) lvgl_test_ui: show_test_results done
I (18519) lvgl_test_ui: Test sequence completed. Result: FAIL.
I (18519) BMGR_DISPLAY_LVGL: Example Finished. Exiting app_main...
...
I (18629) main_task: Returned from app_main()
```

## Troubleshooting

### `idf.py bmgr` command not found

- Make sure `esp-bmgr-assist` is installed in the current ESP-IDF Python environment.
- Make sure `main/idf_component.yml` contains the `esp_board_manager` dependency.
- If using the legacy entry point, make sure `IDF_EXTRA_ACTIONS_PATH` points to `esp_board_manager`.

```shell
# Linux / macOS:
echo $IDF_EXTRA_ACTIONS_PATH

# Windows PowerShell:
echo $env:IDF_EXTRA_ACTIONS_PATH

# Windows CMD:
echo %IDF_EXTRA_ACTIONS_PATH%
```