Page 1 of 1

ESP32S3 i80 data read

Posted: Thu May 30, 2024 9:48 am
by techtoys
Hi

I am porting a new LCD graphic controller to ESP32S3 on i80 8/16-bit interface. Data write to i80 is OK and the display is working (both native 2D graphics and LVGL demo). To go further I need to read data from i80 interface as well.

Is there any guideline on this?

John

Re: ESP32S3 i80 data read

Posted: Fri May 31, 2024 5:19 am
by techtoys
The difficulty here is that, there is no rd_gpio_num in struct esp_lcd_i80_bus_t. Only wr_gpio_num is available that means the native i80 interface in the IDF is designated to use write pin ONLY.

I could define a gpio pin as rd_gpio_num and change the port gpio direction to input to manually strobe the rd pin from high to low to read the port.
In this case, do I need to use esp_lcd_del_i80_bus() to configure the port as GPIO input before i80 read and then call esp_lcd_new_i80_bus() everytime after reading? It seems very complicated to do this.