ESP32-S3 + ST7796s

[Lenergy1982-droid]

Hello!
Is it possible to use a ST7796s display in this project?
Trying to do ESP32-S3 with PSRAM + ST7796s, but the best I achieved is this RGB pattern on the display:

Here is the complete code:

from machine import SPI, Pin
import sys
import lcd_bus
import st7796
import lvgl as lv
from micropython import const


lv.init()

spi_bus = SPI.Bus(host = 1, mosi=15, miso=16, sck=17)

display_bus = lcd_bus.SPIBus(
    spi_bus=spi_bus,
    dc=4,
    cs=18,
    freq=80000000
)

display = st7796.ST7796(
    data_bus=display_bus,
    display_width=480,
    display_height=320,
    #backlight_pin=_BL,
    reset_pin=5,
    power_pin=3,
    reset_state=st7796.STATE_LOW,
    color_space=lv.COLOR_FORMAT.RGB565,
    color_byte_order=st7796.BYTE_ORDER_BGR,
    rgb565_byte_swap=True
)



display.set_power(True)
display.init()

scrn = lv.screen_active()
scrn.set_style_bg_color(lv.color_hex(0x000000), 0)

slider = lv.slider(scrn)
slider.set_size(300, 50)
slider.center()

label = lv.label(scrn)
label.set_text('HELLO WORLD!')
label.align(lv.ALIGN.CENTER, 0, -50)

"DISPLAY = ST7796" was added to the build string.
What I have tried:
host = 2 in spi_bus = SPI.Bus()
color_byte_order=st7796.BYTE_ORDER_RGB,
rgb565_byte_swap=False
Changing pins to which display is attached.

Please, help! How to make this setup work? Can ST7796S and ST7796 use the same driver?

[kdschlosser]

because you are using a wired connection to the display you might want to try lowering the SPI frequency down to 20mhz and see if that solves the issue.

You also want to use the hardware SPI pins for a given host. host 0 (SPI1) is reserved for SPIRAM and flash and host 1 (SPI2) has hardware pins defined for it. host 2 (SPI3) uses the GPIO matrix and can have any pins assigned.

typedef enum {
//SPI1 can be used as GPSPI only on ESP32
    SPI1_HOST=0,    ///< SPI1
    SPI2_HOST=1,    ///< SPI2
#if SOC_SPI_PERIPH_NUM > 2
    SPI3_HOST=2,    ///< SPI3
#endif
    SPI_HOST_MAX,   ///< invalid host value
} spi_host_device_t;

// this is host 0 or "SPI1_HOST"
#define SPI_IOMUX_PIN_NUM_HD    27
#define SPI_IOMUX_PIN_NUM_CS    29
#define SPI_IOMUX_PIN_NUM_MOSI  32
#define SPI_IOMUX_PIN_NUM_CLK   30
#define SPI_IOMUX_PIN_NUM_MISO  31
#define SPI_IOMUX_PIN_NUM_WP    28

// This is host 1 or SPI2_HOST
#define SPI2_IOMUX_PIN_NUM_HD   9
#define SPI2_IOMUX_PIN_NUM_CS   10
#define SPI2_IOMUX_PIN_NUM_MOSI 11
#define SPI2_IOMUX_PIN_NUM_CLK  12
#define SPI2_IOMUX_PIN_NUM_MISO 13
#define SPI2_IOMUX_PIN_NUM_WP   14

#define SPI2_IOMUX_PIN_NUM_HD_OCT   33
#define SPI2_IOMUX_PIN_NUM_CS_OCT   34
#define SPI2_IOMUX_PIN_NUM_MOSI_OCT 35
#define SPI2_IOMUX_PIN_NUM_CLK_OCT  36
#define SPI2_IOMUX_PIN_NUM_MISO_OCT 37
#define SPI2_IOMUX_PIN_NUM_WP_OCT   38
#define SPI2_IOMUX_PIN_NUM_IO4_OCT  10
#define SPI2_IOMUX_PIN_NUM_IO5_OCT  11
#define SPI2_IOMUX_PIN_NUM_IO6_OCT  12
#define SPI2_IOMUX_PIN_NUM_IO7_OCT  13

connect the pins from the display to these pins on the ESP32-S3
mosi=11
clk=12
miso=13
cs=10

from machine import SPI, Pin
import sys
import lcd_bus
import st7796
import lvgl as lv
from micropython import const


lv.init()

spi_bus = SPI.Bus(host = 1, mosi=11, miso=13, sck=12)

display_bus = lcd_bus.SPIBus(
    spi_bus=spi_bus,
    dc=4,
    cs=10,
    freq=20000000  # increase this onmce you have it up and running
)

display = st7796.ST7796(
    data_bus=display_bus,
    display_width=480,
    display_height=320,
    #backlight_pin=_BL,
    reset_pin=5,
    power_pin=3,
    reset_state=st7796.STATE_LOW,
    color_space=lv.COLOR_FORMAT.RGB565,
    color_byte_order=st7796.BYTE_ORDER_BGR,
    rgb565_byte_swap=True
)



display.set_power(True)
display.init()

scrn = lv.screen_active()
scrn.set_style_bg_color(lv.color_hex(0x000000), 0)

slider = lv.slider(scrn)
slider.set_size(300, 50)
slider.center()

label = lv.label(scrn)
label.set_text('HELLO WORLD!')
label.align(lv.ALIGN.CENTER, 0, -50)

import task_handler
task_handler.TaskHandler()  # this is what updated the frame buffer. Without this it's not going to display anything. 

[Lenergy1982-droid]

Hurrraaaaaayyyy!!!!!!!!))))))))))))))))) I works!! Thank you very much! Now I can go further and change my project code for the new version of LVGL.
All this time I was testing without this line: task_handler.TaskHandler()

The final code for me:

from machine import SPI, Pin
import sys
import lcd_bus
import st7796
import lvgl as lv
from micropython import const


lv.init()

spi_bus = SPI.Bus(host = 1, mosi=11, miso=13, sck=12)

display_bus = lcd_bus.SPIBus(
    spi_bus=spi_bus,
    dc=4,
    cs=10,
    freq=80000000
)

display = st7796.ST7796(
    data_bus=display_bus,
    display_width=320,
    display_height=480,
    #backlight_pin=_BL,
    reset_pin=5,
    power_pin=3,
    reset_state=st7796.STATE_LOW,
    color_space=lv.COLOR_FORMAT.RGB565,
    color_byte_order=st7796.BYTE_ORDER_BGR,
    rgb565_byte_swap=True
)



display.set_power(True)
display.init()
display.set_rotation(lv.DISPLAY_ROTATION._90)

scrn = lv.screen_active()
scrn.set_style_bg_color(lv.color_hex(0x000000), 0)

slider = lv.slider(scrn)
slider.set_size(300, 50)
slider.center()

label = lv.label(scrn)
label.set_text('HELLO WORLD!')
label.align(lv.ALIGN.CENTER, 0, -50)

import task_handler
task_handler.TaskHandler(33)

Thank you very much again!

[kdschlosser]

no worries m8. as I said you really want to use the hardware SPI pins if possible. This is because the SPI will run at a faster speed than if it has to go through the GPIO martix on the ESP32.

[kdschlosser]

Glad when problems are simple to fix like this was.