No backlight on ESP32-4848S040C_I_Y_1

[KevinvOosterhout]

hi,

I'm completely new to the ESP32 ecosystem so apology if it's a dumb question.

I've cloned the demo repo as follows git clone https://github.com/rzeldent/esp32-smartdisplay-demo.git --recurse-submodules

After which i went to the platformio.ini and uncommented the following: default_envs = esp32-4848S040CIY1

I've uploaded the code to my device and looked at the serial console.

ESP-ROM:esp32s3-20210327
Build:Mar 27 2021
rst:0x1 (POWERON),boot:0x18 (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:1
load:0x3fce3808,len:0x44c
load:0x403c9700,len:0xbd8
load:0x403cc700,len:0x2a80
entry 0x403c98d0
E (126) esp_core_dump_flash: Incorrect size of core dump image: -16776961
[   127][I][esp32-hal-psram.c:96] psramInit(): PSRAM enabled
[   391][I][main.cpp:25] setup(): Board: esp32-4848S040CIY1
[   392][I][main.cpp:26] setup(): CPU: ESP32-S3 rev0, CPU Freq: 240 Mhz, 2 core(s)
[   393][I][main.cpp:27] setup(): Free heap: 314444 bytes
[   398][I][main.cpp:28] setup(): Free PSRAM: 8386279 bytes
[   403][I][main.cpp:29] setup(): SDK version: v4.4.6-dirty
[   409][D][esp32_smartdisplay.c:209] smartdisplay_init(): smartdisplay_init
[   416][D][lvgl_st7701_par.c:25] lvgl_lcd_init(): lvgl_lcd_init
[   686][D][esp32_smartdisplay.c:109] smartdisplay_lcd_set_backlight(): smartdisplay_lcd_set_backlight. duty:0.500000
[   686][D][lvgl_gt911_i2c.c:167] lvgl_touch_init(): lvgl_touch_init
[   692][D][lvgl_gt911_i2c.c:179] lvgl_touch_init(): i2c_param_config. host: 0
[   699][D][lvgl_gt911_i2c.c:181] lvgl_touch_init(): i2c_driver_install host: 0
[   705][D][lvgl_gt911_i2c.c:197] lvgl_touch_init(): esp_lcd_new_panel_io_i2c. host: 0
[   714][D][lvgl_gt911_i2c.c:201] lvgl_touch_init(): GT911 productId: 911
[   720][D][lvgl_gt911_i2c.c:202] lvgl_touch_init(): GT911 fwId: 1060
[   726][D][lvgl_gt911_i2c.c:203] lvgl_touch_init(): GT911 xResolution/yResolution: (480, 480)
[   734][D][lvgl_gt911_i2c.c:204] lvgl_touch_init(): GT911 vendorId: 00
[   741][D][lvgl_gt911_i2c.c:248] lvgl_touch_init(): esp_lcd_touch_new_i2c_gt911. host: 0
[   748][D][esp32_smartdisplay.c:36] lvgl_update_callback(): lvgl_update_callback
[ 16599][D][lvgl_gt911_i2c.c:148] gt911_lvgl_touch_cb(): Pressed at: (260,194), strength: 1070513646
[ 16629][D][lvgl_gt911_i2c.c:148] gt911_lvgl_touch_cb(): Pressed at: (260,194), strength: 1070513646
[ 16659][D][lvgl_gt911_i2c.c:148] gt911_lvgl_touch_cb(): Pressed at: (260,194), strength: 1070513646
[ 16689][D][lvgl_gt911_i2c.c:148] gt911_lvgl_touch_cb(): Pressed at: (260,194), strength: 1070513646
[ 16719][D][lvgl_gt911_i2c.c:148] gt911_lvgl_touch_cb(): Pressed at: (260,194), strength: 1070513646
[ 16749][D][lvgl_gt911_i2c.c:148] gt911_lvgl_touch_cb(): Pressed at: (260,194), strength: 1070513646
[ 16779][D][lvgl_gt911_i2c.c:148] gt911_lvgl_touch_cb(): Pressed at: (260,194), strength: 1070513646

So the touchscreen looks to be working as i'm touching it. But the display is completely dark (No backlight), When i shine my flashlight on the screen i can see some faint shapes and text so i suspect the only issue is the backlight not turning on. Did i forget to change something?

[GilchristT]

@KevinvOosterhout I have exactly the same problem. I've found that setting the backlight duty to 1 after smartdisplay_init seems to do the needful.

void setup()
{
  smartdisplay_init();
  smartdisplay_lcd_set_backlight(1);

  auto disp = lv_disp_get_default();
  ...

Hope this helps.

[rzeldent]

Can you try the develop branch?

Maybe similar issue: https://github.com/rzeldent/esp32-smartdisplay-demo/issues/21

[KevinvOosterhout]

Can you try the develop branch?

Maybe similar issue: #21

I've tried the Develop branch but the backlight is not turning on. When adding the smartdisplay_lcd_set_backlight(1); it does work.

[rzeldent]

Hi Kevin,

You're just running the demo, not using any PWM?

You could try to change the PWN channel or the PWN Freqency. PWM currently at the last available channel. See smartdisplay.h

#define PWM_CHANNEL_BCKL (SOC_LEDC_CHANNEL_NUM - 1)
#define PWM_FREQ_BCKL 20000

Play a bit with these (not full backlight but 0.5f) and let me know if it helps!

[Belinda-Bird]

I have exactly the same display, just with 3 relays.

The PWM frequency is too high at 20000Hz I changed it to 600 #define PWM_FREQ_BCKL 600

[bordeux]

600hz also works for me. Except that , the device now giving the sound noise low frequency .

By adding smartdisplay_lcd_set_backlight(1); backlight is working fine, without noise

[winitboonkliang]

issue

• no blacklight
• reboot

ESP-ROM:esp32s3-20210327 Build:Mar 27 2021 rst:0xc (RTC_SW_CPU_RST),boot:0x18 (SPI_FAST_FLASH_BOOT) Saved PC:0x42053c4a SPIWP:0xee mode:DIO, clock div:1 load:0x3fce3808,len:0x44c load:0x403c9700,len:0xbd8 load:0x403cc700,len:0x2a80 entry 0x403c98d0 [ 145][I][esp32-hal-psram.c:96] psramInit(): PSRAM enabled [ 5160][I][main.cpp:29] setup(): Board: esp32-4848S040CIY1 [ 5160][I][main.cpp:30] setup(): CPU: ESP32-S3 rev0, CPU Freq: 240 Mhz, 2 core(s) [ 5161][I][main.cpp:31] setup(): Free heap: 314580 bytes [ 5166][I][main.cpp:32] setup(): Free PSRAM: 8386279 bytes [ 5171][I][main.cpp:33] setup(): SDK version: v4.4.6-dirty ESP_ERROR_CHECK failed: esp_err_t 0x106 (ESP_ERR_NOT_SUPPORTED) at 0x4037b6d8 file: ".pio/libdeps/esp32-4848S040CIY1/esp32_smartdisplay/src/lvgl_panel_st7701_par.c" line 104 func: lvgl_lcd_init expression: esp_lcd_panel_swap_xy(panel_handle, DISPLAY_SWAP_XY)

abort() was called at PC 0x4037b6db on core 1

Backtrace: 0x40377eb2:0x3fcebc70 0x4037b6e5:0x3fcebc90 0x40381605:0x3fcebcb0 0x4037b6db:0x3fcebd30 0x42029c3c:0x3fcebd50 0x42029b5e:0x3fcebe50 0x42002898:0x3fcebe70 0x4202d8fe:0x3fcebeb0

ELF file SHA256: 964cf2b16bfe70b0

Rebooting...

[rzeldent]

LS,

Has to do with the missing functions to swap/mirror on the panels. Was added by mistake and should be working now... See PR: https://github.com/rzeldent/esp32-smartdisplay/pull/152

[winitboonkliang]

work perfect . thank you