Not able to integrate Multiple display

[shrynikjain]

Hi bdbarnett, Trying to integrate two same size display driver ili9341. I have created two display bus in board_config.py and in lv_config.py Using same SPI Bus with different cs pin on esp32-s3 which have 8MB PSRAM and 8MB PSROM using micropython 1.20. Compiled and build from [kdschlosser] repo, I am not able get how to integrate two display. I am attaching board_config file and lv_config file and screenshot of obtained result on display. Could you help with one example how to integrate more than one display using same SPI for micropython lvgl. board_config.txt lv_config.txt sample_pgrm.txt

[bdbarnett]

I haven't tried with multiple displays, so I'm not sure if it will work in the current implementation, but that is certainly something I am interested in implementing. Here are a few things I would try:

in board_config.py, you have

from lib.lcd_bus import SPIBus

That is forcing it to use lcd_bus.py, the MicroPython implementation of lcd_bus. Since you are using an ESP32, the lcd_bus written in C and included with @kdschlosser's build will be faster. Try removing lib. from that line. Also, you have quad_spi=True. lcd_bus.py ignores this because it doesn't support quad_spi. When you remove lib. as recommended, be sure to make quad_spi=False.

For the rest of this, reference: https://docs.lvgl.io/master/overview/display.html

In sample_pgrm.py, you've commented out the line

#from lv_config import display,display1

Uncomment that. When only using a single display, you don't need to worry with this because lv.screen_load() is "always applied on the most recently created (default) display". When using multiple displays, you need to specify which display to put the screen on with lv.display_load_screen(disp, scr). To assign a screen to the non-default display, format it like:

lv.display_load_screen(display._disp_drv, scr)
lv.display_load_screen(display1._disp_drv, scr1)

I'm seeing now that I should have named it disp_drv instead of _disp_drv. I'll probably change that in a future revision of lv_driver_framework.py.

[shrynikjain]

Thank you for the reply, as according to your suggestion i tried "lv.display_load_screen(display._disp_drv, scr)" but getting error as follows, "Traceback (most recent call last): File "", line 69, in AttributeError: 'module' object has no attribute 'display_load_screen'"

could you guide what i am missing and where im doing wrong.

[kdschlosser]

are you using a shared bus? meaning are the displays sharing the same SPI lines? or do you have 2 completely separate sets of connections to the MCU?

[bdbarnett]

@shrynikjain Sorry about that. I gave you the wrong function to call. A lot has changed from lvgl 8.3, which is what I'm used to, and 9.0. The function is

lv.display_load_scr

not

lv.display_load_screen

[shrynikjain]

are you using a shared bus? meaning are the displays sharing the same SPI lines? or do you have 2 completely separate sets of connections to the MCU?

Thank you for the reply, I'm using same SPI lines(Bus) with different CS pin

[shrynikjain]

@shrynikjain Sorry about that. I gave you the wrong function to call. A lot has changed from lvgl 8.3, which is what I'm used to, and 9.0. The function is

lv.display_load_scr

not

lv.display_load_screen

Thank you for the reply, I'll check.

[kdschlosser]

are you using the same spi host number for both as well?

[shrynikjain]

are you using the same spi host number for both as well?

i am using diffrent spi host number for display1 using spihost as '0' and for display2 using spihost as '1'

[kdschlosser]

NO, they need to both use the same SPI host number. If they are using the same pins they both must use the same host number.

[kdschlosser]

and you should never use SPI host 0 if you are using an ESP32 device. That host is reserved for SPIRAM and SPIFLASH. use either host 1 or host 2 if it is supported.

My recommendation is for you to use hardware SPI pins. This will perform better.