LCD display corruption caused by Wi-Fi activities (IDFGH-11174)

[GaryChan-work]

Answers checklist.

• [X] I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• [X] I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• [X] I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

Hi,

We found that the LCD display screen may be corrupted (see link below) if Wi-Fi is connected and has some activities (e.g. communicating with host, performing OTA update, etc). If Wi-Fi is turned off, the display works fine. Besides, the LCD display buffer is placed in the PSRAM (Octal mode@80MHz). If we temporarily change it to internal RAM, it seems the problem can be avoided.

https://drive.google.com/file/d/1J46mps4F4HuG6tB0qJbvmQMnisdy4Jf3/view?usp=sharing

Here is the IDF information: IDF version: v4.4.4 (patched with commit "3cec3a00260") LVGL version: v7.11 Display Buffer: PSRAM (Octal Mode@80MHz) ESP LCD I/F: i80 bus, 8-bit bus width, 16-bit RGB, 10MHz pixel CLK

Can anyone help to see how to fix this issue or know the root cause? Thanks for your help!

Gary

[suda-morris]

It's due to a hardware limitation in the MEM_SPI bandwidth. We recommend you to enable these default Kconfig options: https://github.com/espressif/esp-idf/blob/master/examples/peripherals/lcd/i80_controller/sdkconfig.defaults.esp32s3

Also can you see the problem on the master branch?

You may also get some hints in this FAQ (although different LCD model, but same root cause): https://docs.espressif.com/projects/espressif-esp-faq/en/latest/software-framework/peripherals/lcd.html#does-esp32-s3-require-an-external-psram-to-use-the-rgb-screen

[puddletowntom]

Hi,

I have a similar issue. I made changes to the config as you mention here but it didnt work. Did you make any progress with this? Is there a way of switching PSRAM off for Wi-Fi while having PSRAM on for the LCD.

The similar issue i raised can be found here,

https://github.com/espressif/esp-idf/issues/13169