Display with PWM LEDC only visible when percent > 85 in backlight->setBrightness(int percent) #188

t0menas · 2025-04-21T21:54:52Z

Screen unvisible until backlight->setBrightness(int percent) is set to 85 and above. Also very noticeable non-linear adjustment is happening between 95-96-97 percent.

Here you can see Issue's video representation

Is this normal behaviour? Or maybe I'm doing something wrong?

Board: BOARD_JINGCAI_ESP32_4848S040C_I_Y_3
I configured BOARD_JINGCAI_ESP32_4848S040C_I_Y_3.h header file, and by default it uses PWM backlight control.

BOARD_JINGCAI_ESP32_4848S040C_I_Y_3.h

#pragma once

// *INDENT-OFF*

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////// Please update the following macros to configure general panel /////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * @brief Board name
 */
#define ESP_PANEL_BOARD_NAME                "Jingcai:ESP32_4848S040C_I_Y_3"

/**
 * @brief Panel resolution configuration in pixels
 */
#define ESP_PANEL_BOARD_WIDTH               (480)   // Panel width (horizontal, in pixels)
#define ESP_PANEL_BOARD_HEIGHT              (480)   // Panel height (vertical, in pixels)

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////// Please update the following macros to configure the LCD panel /////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * @brief LCD panel configuration flag (0/1)
 *
 * Set to `1` to enable LCD panel support, `0` to disable
 */
#define ESP_PANEL_BOARD_USE_LCD             (1)

#if ESP_PANEL_BOARD_USE_LCD
/**
 * @brief LCD controller selection
 */
#define ESP_PANEL_BOARD_LCD_CONTROLLER      ST7701

/**
 * @brief LCD bus type selection
 */
#define ESP_PANEL_BOARD_LCD_BUS_TYPE        (ESP_PANEL_BUS_TYPE_RGB)

/**
 * @brief LCD bus parameters configuration
 *
 * Configure parameters based on the selected bus type. Parameters for other bus types will be ignored.
 * For detailed parameter explanations, see:
 * https://docs.espressif.com/projects/esp-idf/en/v5.3.1/esp32s3/api-reference/peripherals/lcd/index.html
 * https://docs.espressif.com/projects/esp-iot-solution/en/latest/display/lcd/index.html
 */
#if ESP_PANEL_BOARD_LCD_BUS_TYPE == ESP_PANEL_BUS_TYPE_RGB

    /**
     * @brief RGB bus parameters configuration
     */
    /**
     * Set to 0 if using simple "RGB" interface which does not contain "3-wire SPI" interface.
     */
    #define ESP_PANEL_BOARD_LCD_RGB_USE_CONTROL_PANEL       (1) // 0/1. Typically set to 1

#if ESP_PANEL_BOARD_LCD_RGB_USE_CONTROL_PANEL
    /* For control panel (3wire-SPI) */
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_IO_CS               (39)
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_IO_SCK              (48)
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_IO_SDA              (47)
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_CS_USE_EXPNADER     (0) // Set to 1 if the signal is controlled by an IO expander
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_SCL_USE_EXPNADER    (0) // Set to 1 if the signal is controlled by an IO expander
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_SDA_USE_EXPNADER    (0) // Set to 1 if the signal is controlled by an IO expander
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_MODE                (0) // 0-3, typically set to 0
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_CMD_BYTES           (1) // Typically set to 8
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_PARAM_BYTES         (1) // Typically set to 8
    #define ESP_PANEL_BOARD_LCD_RGB_SPI_USE_DC_BIT          (1) // 0/1. Typically set to 1
#endif // ESP_PANEL_BOARD_LCD_RGB_USE_CONTROL_PANEL
    /* For refresh panel (RGB) */
    #define ESP_PANEL_BOARD_LCD_RGB_CLK_HZ          (26 * 1000 * 1000)
                                                            // To increase the upper limit of the PCLK, see: https://docs.espressif.com/projects/esp-faq/en/latest/software-framework/peripherals/lcd.html#how-can-i-increase-the-upper-limit-of-pclk-settings-on-esp32-s3-while-ensuring-normal-rgb-screen-display
    #define ESP_PANEL_BOARD_LCD_RGB_HPW             (10)
    #define ESP_PANEL_BOARD_LCD_RGB_HBP             (10)
    #define ESP_PANEL_BOARD_LCD_RGB_HFP             (20)
    #define ESP_PANEL_BOARD_LCD_RGB_VPW             (10)
    #define ESP_PANEL_BOARD_LCD_RGB_VBP             (10)
    #define ESP_PANEL_BOARD_LCD_RGB_VFP             (10)
    #define ESP_PANEL_BOARD_LCD_RGB_PCLK_ACTIVE_NEG (0)     // 0: rising edge, 1: falling edge. Typically set to 0
                                                                                        // The following sheet shows the valid combinations of
                                                                                        // data width and pixel bits:
                                                                                        // ┏---------------------------------┳- -------------------------------┓
    #define ESP_PANEL_BOARD_LCD_RGB_DATA_WIDTH      (16)                                // |                16               |               8                 |
    #define ESP_PANEL_BOARD_LCD_RGB_PIXEL_BITS      (ESP_PANEL_LCD_COLOR_BITS_RGB565)   // | ESP_PANEL_LCD_COLOR_BITS_RGB565 | ESP_PANEL_LCD_COLOR_BITS_RGB888 |
                                                                                        // ┗---------------------------------┻---------------------------------┛
                                                            // To understand color format of RGB LCD, see: https://docs.espressif.com/projects/esp-iot-solution/en/latest/display/lcd/rgb_lcd.html#color-formats
    #define ESP_PANEL_BOARD_LCD_RGB_BOUNCE_BUF_SIZE (ESP_PANEL_BOARD_WIDTH * 10)
                                                            // Bounce buffer size in bytes. It is used to avoid screen drift
                                                            // for ESP32-S3. Typically set to `ESP_PANEL_BOARD_WIDTH * 10`
                                                            // The size should satisfy `size * N = LCD_width * LCD_height`,
                                                            // where N is an even number.
                                                            // For more details, see: https://github.com/esp-arduino-libs/ESP32_Display_Panel/blob/master/docs/FAQ.md#how-to-fix-screen-drift-issue-when-driving-rgb-lcd-with-esp32-s3
    #define ESP_PANEL_BOARD_LCD_RGB_IO_HSYNC        (16)
    #define ESP_PANEL_BOARD_LCD_RGB_IO_VSYNC        (17)
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DE           (18)    // -1 if not used
    #define ESP_PANEL_BOARD_LCD_RGB_IO_PCLK         (21)
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DISP         (-1)    // -1 if not used. Typically set to -1

                                                            // The following sheet shows the mapping of ESP GPIOs to
                                                            // LCD data pins with different data width and color format:
                                                            // ┏------┳- ------------┳--------------------------┓
                                                            // | ESP: | 8-bit RGB888 |      16-bit RGB565       |
                                                            // |------|--------------|--------------------------|
                                                            // | LCD: |    RGB888    | RGB565 | RGB666 | RGB888 |
                                                            // ┗------|--------------|--------|--------|--------|
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA0        (4)    //        |      D0      |   B0   |  B0-1  |   B0-3 |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA1        (5)    //        |      D1      |   B1   |  B2    |   B4   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA2        (6)    //        |      D2      |   B2   |  B3    |   B5   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA3        (7)    //        |      D3      |   B3   |  B4    |   B6   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA4        (15)    //        |      D4      |   B4   |  B5    |   B7   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA5        (8)    //        |      D5      |   G0   |  G0    |   G0-2 |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA6        (20)    //        |      D6      |   G1   |  G1    |   G3   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA7        (3)    //        |      D7      |   G2   |  G2    |   G4   |
#if ESP_PANEL_BOARD_LCD_RGB_DATA_WIDTH > 8                  //        ┗--------------┫--------|--------|--------|
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA8        (46)    //                       |   G3   |  G3    |   G5   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA9        (9)    //                       |   G4   |  G4    |   G6   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA10       (10)    //                       |   G5   |  G5    |   G7   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA11       (11)    //                       |   R0   |  R0-1  |   R0-3 |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA12       (12)    //                       |   R1   |  R2    |   R4   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA13       (13)    //                       |   R2   |  R3    |   R5   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA14       (14)    //                       |   R3   |  R4    |   R6   |
    #define ESP_PANEL_BOARD_LCD_RGB_IO_DATA15       (0)    //                       |   R4   |  R5    |   R7   |
                                                            //                       ┗--------┻--------┻--------┛
#endif // ESP_PANEL_BOARD_LCD_RGB_DATA_WIDTH

#endif // ESP_PANEL_BOARD_LCD_BUS_TYPE

/**
 * @brief LCD specific flags configuration
 *
 * These flags are specific to the "3-wire SPI + RGB" bus.
 */
#if (ESP_PANEL_BOARD_LCD_BUS_TYPE == ESP_PANEL_BUS_TYPE_RGB) && ESP_PANEL_BOARD_LCD_RGB_USE_CONTROL_PANEL
/**
 * @brief Enable IO multiplex
 *
 * Set to 1 if the 3-wire SPI pins are sharing other pins of the RGB interface to save GPIOs. Then, the control panel
 * and its pins (except CS signal) will be released after LCD call `init()`. All `*_by_cmd` flags will be invalid.
 */
#define ESP_PANEL_BOARD_LCD_FLAGS_ENABLE_IO_MULTIPLEX       (0) // typically set to 0
/**
 * @brief Mirror by command
 *
 * Set to 1 if the `mirror()` function will be implemented by LCD command. Otherwise, the function will be implemented by
 * software. Only valid when `ESP_PANEL_BOARD_LCD_FLAGS_ENABLE_IO_MULTIPLEX` is 0.
 */
#define ESP_PANEL_BOARD_LCD_FLAGS_MIRROR_BY_CMD             (!ESP_PANEL_BOARD_LCD_FLAGS_ENABLE_IO_MULTIPLEX)
#endif // ESP_PANEL_BOARD_LCD_RGB_USE_CONTROL_PANEL

/**
 * @brief LCD vendor initialization commands
 *
 * Vendor specific initialization can be different between manufacturers, should consult the LCD supplier for
 * initialization sequence code. Please uncomment and change the following macro definitions. Otherwise, the LCD driver
 * will use the default initialization sequence code.
 *
 * The initialization sequence can be specified in two formats:
 * 1. Raw format:
 *    {command, (uint8_t []){data0, data1, ...}, data_size, delay_ms}
 * 2. Helper macros:
 *    - ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(delay_ms, command, {data0, data1, ...})
 *    - ESP_PANEL_LCD_CMD_WITH_NONE_PARAM(delay_ms, command)
 */
#define ESP_PANEL_BOARD_LCD_VENDOR_INIT_CMD()                       \
    {                                                               \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xFF, {0x77, 0x01, 0x00, 0x00, 0x10}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xC0, {0x3B, 0x00}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xC1, {0x0D, 0x02}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xC2, {0x31, 0x05}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xCD, {0x00}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB0, {0x00, 0x11, 0x18, 0x0E, 0x11, 0x06, 0x07, 0x08, 0x07, 0x22, 0x04, 0x12, 0x0F, 0xAA, 0x31, 0x18}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB1, {0x00, 0x11, 0x19, 0x0E, 0x12, 0x07, 0x08, 0x08, 0x08, 0x22, 0x04, 0x11, 0x11, 0xA9, 0x32, 0x18}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xFF, {0x77, 0x01, 0x00, 0x00, 0x11}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB0, {0x60}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB1, {0x32}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB2, {0x07}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB3, {0x80}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB5, {0x49}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB7, {0x85}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xB8, {0x21}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xC1, {0x78}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xC2, {0x78}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE0, {0x00, 0x1B, 0x02}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE1, {0x08, 0xA0, 0x00, 0x00, 0x07, 0xA0, 0x00, 0x00, 0x00, 0x44, 0x44}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE2, {0x11, 0x11, 0x44, 0x44, 0xED, 0xA0, 0x00, 0x00, 0xEC, 0xA0, 0x00, 0x00}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE3, {0x00, 0x00, 0x11, 0x11}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE4, {0x44, 0x44}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE5, {0x0A, 0xE9, 0xD8, 0xA0, 0x0C, 0xEB, 0xD8, 0xA0, 0x0E, 0xED, 0xD8, 0xA0, 0x10, 0xEF, 0xD8, 0xA0}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE6, {0x00, 0x00, 0x11, 0x11}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE7, {0x44, 0x44}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE8, {0x09, 0xE8, 0xD8, 0xA0, 0x0B, 0xEA, 0xD8, 0xA0, 0x0D, 0xEC, 0xD8, 0xA0, 0x0F, 0xEE, 0xD8, 0xA0}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xEB, {0x02, 0x00, 0xE4, 0xE4, 0x88, 0x00, 0x40}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xEC, {0x3C, 0x00}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xED, {0xAB, 0x89, 0x76, 0x54, 0x02, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x20, 0x45, 0x67, 0x98, 0xBA}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xFF, {0x77, 0x01, 0x00, 0x00, 0x13}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xE5, {0xE4}), \
        ESP_PANEL_LCD_CMD_WITH_8BIT_PARAM(0, 0xFF, {0x77, 0x01, 0x00, 0x00, 0x00}), \
        ESP_PANEL_LCD_CMD_WITH_NONE_PARAM(120, 0x11), \
    }

/**
 * @brief LCD color configuration
 */
#define ESP_PANEL_BOARD_LCD_COLOR_BITS          (ESP_PANEL_LCD_COLOR_BITS_RGB666)
                                                        // ESP_PANEL_LCD_COLOR_BITS_RGB565/RGB666/RGB888
#define ESP_PANEL_BOARD_LCD_COLOR_BGR_ORDER     (0)     // 0: RGB, 1: BGR
#define ESP_PANEL_BOARD_LCD_COLOR_INEVRT_BIT    (0)     // 0/1

/**
 * @brief LCD transformation configuration
 */
#define ESP_PANEL_BOARD_LCD_SWAP_XY             (0)     // 0/1
#define ESP_PANEL_BOARD_LCD_MIRROR_X            (0)     // 0/1
#define ESP_PANEL_BOARD_LCD_MIRROR_Y            (0)     // 0/1
#define ESP_PANEL_BOARD_LCD_GAP_X               (0)     // [0, ESP_PANEL_BOARD_WIDTH]
#define ESP_PANEL_BOARD_LCD_GAP_Y               (0)     // [0, ESP_PANEL_BOARD_HEIGHT]

/**
 * @brief LCD reset pin configuration
 */
#define ESP_PANEL_BOARD_LCD_RST_IO              (-1)    // Reset pin, -1 if not used
#define ESP_PANEL_BOARD_LCD_RST_LEVEL           (0)     // Reset active level, 0: low, 1: high

#endif // ESP_PANEL_BOARD_USE_LCD

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////// Please update the following macros to configure the touch panel ///////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * @brief Touch panel configuration flag (0/1)
 *
 * Set to `1` to enable touch panel support, `0` to disable
 */
#define ESP_PANEL_BOARD_USE_TOUCH               (1)

#if ESP_PANEL_BOARD_USE_TOUCH
/**
 * @brief Touch controller selection
 */
#define ESP_PANEL_BOARD_TOUCH_CONTROLLER        GT911

/**
 * @brief Touch bus type selection
 *
 * Supported types:
 * - `ESP_PANEL_BUS_TYPE_I2C`
 * - `ESP_PANEL_BUS_TYPE_SPI`
 */
#define ESP_PANEL_BOARD_TOUCH_BUS_TYPE          (ESP_PANEL_BUS_TYPE_I2C)

#if (ESP_PANEL_BOARD_TOUCH_BUS_TYPE == ESP_PANEL_BUS_TYPE_I2C) || \
    (ESP_PANEL_BOARD_TOUCH_BUS_TYPE == ESP_PANEL_BUS_TYPE_SPI)
/**
 * If set to 1, the bus will skip to initialize the corresponding host. Users need to initialize the host in advance.
 *
 * For drivers which created by this library, even if they use the same host, the host will be initialized only once.
 * So it is not necessary to set the macro to `1`. For other drivers (like `Wire`), please set the macro to `1`
 * ensure that the host is initialized only once.
 */
#define ESP_PANEL_BOARD_TOUCH_BUS_SKIP_INIT_HOST        (0)     // 0/1. Typically set to 0
#endif

/**
 * @brief Touch bus parameters configuration
 */
#if ESP_PANEL_BOARD_TOUCH_BUS_TYPE == ESP_PANEL_BUS_TYPE_I2C

    /**
     * @brief I2C bus
     */
    /* For general */
    #define ESP_PANEL_BOARD_TOUCH_I2C_HOST_ID           (0)     // Typically set to 0
#if !ESP_PANEL_BOARD_TOUCH_BUS_SKIP_INIT_HOST
    /* For host */
    #define ESP_PANEL_BOARD_TOUCH_I2C_CLK_HZ            (400 * 1000)
                                                                // Typically set to 400K
    #define ESP_PANEL_BOARD_TOUCH_I2C_SCL_PULLUP        (1)     // 0/1. Typically set to 1
    #define ESP_PANEL_BOARD_TOUCH_I2C_SDA_PULLUP        (1)     // 0/1. Typically set to 1
    #define ESP_PANEL_BOARD_TOUCH_I2C_IO_SCL            (45)
    #define ESP_PANEL_BOARD_TOUCH_I2C_IO_SDA            (19)
#endif
    /* For panel */
    #define ESP_PANEL_BOARD_TOUCH_I2C_ADDRESS           (0)     // Typically set to 0 to use the default address.
                                                                // - For touchs with only one address, set to 0
                                                                // - For touchs with multiple addresses, set to 0 or
                                                                //   the address. Like GT911, there are two addresses:
                                                                //   0x5D(default) and 0x14

#endif // ESP_PANEL_BOARD_TOUCH_BUS_TYPE

/**
 * @brief Touch panel transformation flags
 */
#define ESP_PANEL_BOARD_TOUCH_SWAP_XY           (0)     // 0/1
#define ESP_PANEL_BOARD_TOUCH_MIRROR_X          (0)     // 0/1
#define ESP_PANEL_BOARD_TOUCH_MIRROR_Y          (0)     // 0/1

/**
 * @brief Touch panel control pins
 */
#define ESP_PANEL_BOARD_TOUCH_RST_IO            (-1)    // Reset pin, -1 if not used
#define ESP_PANEL_BOARD_TOUCH_RST_LEVEL         (0)     // Reset active level, 0: low, 1: high
#define ESP_PANEL_BOARD_TOUCH_INT_IO            (-1)    // Interrupt pin, -1 if not used
#define ESP_PANEL_BOARD_TOUCH_INT_LEVEL         (0)     // Interrupt active level, 0: low, 1: high

#endif // ESP_PANEL_BOARD_USE_TOUCH

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////// Please update the following macros to configure the backlight ////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * @brief Backlight configuration flag (0/1)
 *
 * Set to `1` to enable backlight support, `0` to disable
 */
#define ESP_PANEL_BOARD_USE_BACKLIGHT           (1)

#if ESP_PANEL_BOARD_USE_BACKLIGHT
/**
 * @brief Backlight control type selection
 */
#define ESP_PANEL_BOARD_BACKLIGHT_TYPE          (ESP_PANEL_BACKLIGHT_TYPE_PWM_LEDC)

#if (ESP_PANEL_BOARD_BACKLIGHT_TYPE == ESP_PANEL_BACKLIGHT_TYPE_SWITCH_GPIO) || \
    (ESP_PANEL_BOARD_BACKLIGHT_TYPE == ESP_PANEL_BACKLIGHT_TYPE_SWITCH_EXPANDER) || \
    (ESP_PANEL_BOARD_BACKLIGHT_TYPE == ESP_PANEL_BACKLIGHT_TYPE_PWM_LEDC)

    /**
     * @brief Backlight control pin configuration
     */
    #define ESP_PANEL_BOARD_BACKLIGHT_IO        (38)    // Output GPIO pin number
    #define ESP_PANEL_BOARD_BACKLIGHT_ON_LEVEL  (1)     // Active level, 0: low, 1: high

#endif // ESP_PANEL_BOARD_BACKLIGHT_TYPE

/**
 * @brief Backlight idle state configuration (0/1)
 *
 * Set to 1 if want to turn off the backlight after initializing. Otherwise, the backlight will be on.
 */
#define ESP_PANEL_BOARD_BACKLIGHT_IDLE_OFF      (0)

#endif // ESP_PANEL_BOARD_USE_BACKLIGHT

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////// Please update the following macros to configure the IO expander //////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * @brief IO expander configuration flag (0/1)
 *
 * Set to `1` to enable IO expander support, `0` to disable
 */
#define ESP_PANEL_BOARD_USE_EXPANDER            (0)

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////// Please utilize the following macros to execute any additional code if required /////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////// File Version ///////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * Do not change the following versions. These version numbers are used to check compatibility between this
 * configuration file and the library. Rules for version numbers:
 * 1. Major version mismatch: Configurations are incompatible, must use library version
 * 2. Minor version mismatch: May be missing new configurations, recommended to update
 * 3. Patch version mismatch: No impact on functionality
 */
#define ESP_PANEL_BOARD_CUSTOM_FILE_VERSION_MAJOR 1
#define ESP_PANEL_BOARD_CUSTOM_FILE_VERSION_MINOR 0
#define ESP_PANEL_BOARD_CUSTOM_FILE_VERSION_PATCH 0

// *INDENT-ON*

Main.cpp

#include <Arduino.h>
#include <esp_display_panel.hpp>
#include <lvgl.h>
#include "lvgl_v8_port.h" 
extern "C" {
#include <ui/screens.h>
#include <ui/ui.h>
}


int counter = 0;
bool once = false;

using namespace esp_panel::drivers;
using namespace esp_panel::board;
esp_panel::drivers::Backlight *backlight;

void setup() {

  Serial.begin(115200);

  Serial.println("Initializing board");
  Board *board = new Board();

  board->init();
#if LVGL_PORT_AVOID_TEARING_MODE
  auto lcd = board->getLCD();
  // When avoid tearing function is enabled, the frame buffer number should be set in the board driver
  lcd->configFrameBufferNumber(LVGL_PORT_DISP_BUFFER_NUM);
#if ESP_PANEL_DRIVERS_BUS_ENABLE_RGB && CONFIG_IDF_TARGET_ESP32S3
  auto lcd_bus = lcd->getBus();
  /**
   * As the anti-tearing feature typically consumes more PSRAM bandwidth, for the ESP32-S3, we need to utilize the
   * "bounce buffer" functionality to enhance the RGB data bandwidth.
   * This feature will consume `bounce_buffer_size * bytes_per_pixel * 2` of SRAM memory.
   */
  if (lcd_bus->getBasicAttributes().type == ESP_PANEL_BUS_TYPE_RGB) {
      static_cast<BusRGB *>(lcd_bus)->configRGB_BounceBufferSize(lcd->getFrameWidth() * 10);
  }
#endif
#endif
  assert(board->begin());
  backlight = board->getBacklight();
  Serial.println("Initializing LVGL");
  lvgl_port_init(board->getLCD(), board->getTouch());

  Serial.println("Creating UI");
  /* Lock the mutex due to the LVGL APIs are not thread-safe */
  lvgl_port_lock(-1);

  /**
   * Create the simple labels
   */
  lv_obj_t *label_1 = lv_label_create(lv_scr_act());
  lv_label_set_text(label_1, "Hello World!");
  lv_obj_set_style_text_font(label_1, &lv_font_montserrat_30, 0);
  lv_obj_align(label_1, LV_ALIGN_CENTER, 0, -20);
  lv_obj_t *label_2 = lv_label_create(lv_scr_act());
  lv_label_set_text_fmt(
      label_2, "ESP32_Display_Panel(%d.%d.%d)",
      ESP_PANEL_VERSION_MAJOR, ESP_PANEL_VERSION_MINOR, ESP_PANEL_VERSION_PATCH
  );
  lv_obj_set_style_text_font(label_2, &lv_font_montserrat_16, 0);
  lv_obj_align_to(label_2, label_1, LV_ALIGN_OUT_BOTTOM_MID, 0, 10);
  lv_obj_t *label_3 = lv_label_create(lv_scr_act());
  lv_label_set_text_fmt(label_3, "LVGL(%d.%d.%d)", LVGL_VERSION_MAJOR, LVGL_VERSION_MINOR, LVGL_VERSION_PATCH);
  lv_obj_set_style_text_font(label_3, &lv_font_montserrat_16, 0);
  lv_obj_align_to(label_3, label_2, LV_ALIGN_OUT_BOTTOM_MID, 0, 10);


  /* Release the mutex */
  lvgl_port_unlock();

  lvgl_port_lock(-1);

  /* Initialize LVGL UI generated by Squareline */
  ui_init();

  /* Release the mutex */
  lvgl_port_unlock();
  if(backlight == nullptr) {
    Serial.println("Backlight driver not available on this panel");
  }

}

void loop() {
  // put your main code here, to run repeatedly:
  //Serial.println("IDLE loop");
  delay(1000);
  counter++;
  if(!(backlight->setBrightness(80+counter)))
  {
    Serial.println("Failed to set Brightness");
  }
  if(counter == 20)
  {
    counter = 0;
  }
  Serial.print("Screen Brightness: ");Serial.println(backlight->getBrightness());

}

The text was updated successfully, but these errors were encountered:

Lzw655 · 2025-04-23T02:15:40Z

Hi @t0menas,

I reproduced this problem and found that this is caused by the fact that the default output PWM frequency (5K) of LEDC is too high. Reducing it to 1K can solve this problem. I will add a configuration macro for the LEDC frequency in the board configuration file. Thank you for reporting this problem!

t0menas · 2025-04-23T02:19:48Z

@Lzw655 Hi, thanks for taking the time! Wow, really weird that 5kHz is too high

Lzw655 mentioned this issue Apr 23, 2025

feat(backlight): add PWM parameters configuration (#188) #189

Merged

Lzw655 closed this as completed in 2dd7343 Apr 23, 2025

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Display with PWM LEDC only visible when percent > 85 in backlight->setBrightness(int percent) #188

Display with PWM LEDC only visible when percent > 85 in backlight->setBrightness(int percent) #188

t0menas commented Apr 21, 2025 •

edited

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Lzw655 commented Apr 23, 2025

t0menas commented Apr 23, 2025

Display with PWM LEDC only visible when percent > 85 in backlight->setBrightness(int percent) #188

Display with PWM LEDC only visible when percent > 85 in backlight->setBrightness(int percent) #188

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t0menas commented Apr 21, 2025 • edited Loading

Lzw655 commented Apr 23, 2025

t0menas commented Apr 23, 2025

t0menas commented Apr 21, 2025 •

edited

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