Sample ESPHome config for Waveshare 7 ESP32 Display

wave-7.yaml

# For Waveshare 7" ESP32 board.

substitutions:
  friendly_name: Waveshare 7

esphome:
  name: wave-7
  friendly_name: ${friendly_name}
  platformio_options:
    build_unflags: -Werror=all
    board_build.flash_mode: dio


esp32:
  board: esp32-s3-devkitc-1
  framework:
    type: esp-idf
    platform_version: 6.8.1
    version: 5.3.0
    sdkconfig_options:
      CONFIG_ESP32S3_DEFAULT_CPU_FREQ_240: "y"
      CONFIG_ESP32S3_DATA_CACHE_64KB: "y"
      CONFIG_SPIRAM_FETCH_INSTRUCTIONS: y
      CONFIG_SPIRAM_RODATA: y

api:
  encryption:
    key: !secret encryption_key

logger:
  hardware_uart: UART0

wifi: !include wifi.yaml

ota:
  platform: esphome
  password: !secret ota_password

ch422g:

psram:
  mode: octal
  speed: 80MHz

output:
  - platform: ledc
    id: backlight_output
    pin: 13
    frequency: 1220Hz
    inverted: true

# Note: this requires a hardware modification to work - GPIO 13 must be connected to the backlight PWM pad.

light:
  - platform: monochromatic
    output: backlight_output
    name: LCD Backlight
    id: lcd_backlight
    restore_mode: ALWAYS_ON
    default_transition_length: 0s
    gamma_correct: 1.8
    effects:
      - pulse:

i2c:
  sda: 8
  scl: 9
  frequency: 400kHz
  scan: false
  id: bus_a

button:
  - platform: safe_mode
    name: Safe Mode Boot
    entity_category: diagnostic

touchscreen:
  - platform: gt911
    address: 0x5D
    id: my_touchscreen
    interrupt_pin: 4
    reset_pin:
      ch422g:
      number: 1

display:
  - platform: rpi_dpi_rgb
    id: rpi_disp
    #update_interval: never
    #rotation: 90
    auto_clear_enabled: false
    color_order: RGB
    pclk_frequency: 16MHz
    dimensions:
      width: 800
      height: 480
    reset_pin:
      ch422g:
      number: 3
    enable_pin:
      ch422g:
      number: 2
    de_pin:
      number: 5
    hsync_pin:
      number: 46
      ignore_strapping_warning: true
    vsync_pin:
      number: 3
      ignore_strapping_warning: true
    pclk_pin: 7
    pclk_inverted: true
# 7" 800x480 params
    hsync_back_porch: 8
    hsync_front_porch: 8
    hsync_pulse_width: 4
    vsync_back_porch: 16
    vsync_front_porch: 16
    vsync_pulse_width: 4
# 5" 1024x600 params
#    hsync_back_porch: 188
#    hsync_front_porch: 44
#    hsync_pulse_width: 88
#    vsync_back_porch: 16
#    vsync_front_porch: 3
#    vsync_pulse_width: 6
# 4.3" 800x480 params
#    hsync_back_porch: 8
#    hsync_front_porch: 8
#    hsync_pulse_width: 4
#    vsync_back_porch: 16
#    vsync_front_porch: 16
#    vsync_pulse_width: 4

    data_pins:
      red:
        - 1         #r3
        - 2         #r4
        - 42        #r5
        - 41        #r6
        - 40        #r7
      blue:
        - 14        #b3
        - 38        #b4
        - 18        #b5
        - 17        #b6
        - 10        #b7
      green:
        - 39        #g2
        - 0         #g3
        - 45        #g4
        - 48        #g5
        - 47        #g6
        - 21        #g7

lvgl:

I've altered my config file to use GPIO11 on the ESP32 and soldered a wire from GPIO11 to the solder pad. I also added a 30K resisitor at, what I assume to be, R7 (lower right in your image).

After flashing, the screen will turn off but the device will reboot if I try to turn it on again.

Here is my code: https://pastebin.com/ifPc6U2X

It works for me, but you commented out important bits, like the inverted setting on the output. Also, you will need to replace R6 (currently 0R, next to R7) with another value - I used 3K3 but 2K7 might be better. And change the light gamma to 1.0.

That did it @clydebarrow .....thanks. Backlight LED is now responding correctly.