PlatformIO RP2040 and ST7789 without CS PIN Dark/Black Screen

[Hraefns]

Hi newcomer here, I need help with making this library to work on my RP2040(YD-RP2040) and ST7789(Without CS PIN) using PlatformIO. I can confirm the PIN is correct and the TFT is not faulty because I already tried to do a flashing background test manually without any library.

I tried to set TFT_BACKLIGHT_ON to LOW and it's work because my TFT screen goes complete black, I can see a greyish flash when I press the reset button too, but after that all I see just complete black screen.
EDIT: I see the lights kind of flashing in loop but it's still black (so it's like backlight go darker and go lighter if that make sense) but this only happens if I power up my pico with another pico (because I was trying to debug it), if I power it up directly through USB C I can see a slight flash when I press the reset button but that's all no flashing after that.

I already tried to search the platformIO.ini example and this is what I came up with but still no luck:

[env:ydrp2040]
platform = https://github.com/maxgerhardt/platform-raspberrypi.git
board = vccgnd_yd_rp2040
framework = arduino
board_build.core = earlephilhower
board_build.mcu = rp2040
monitor_speed = 115200

lib_deps = 
    LittleFS
    SPI
    bodmer/TFT_eSPI@^2.5.43
    lvgl/[email protected]

build_flags =
    -D PICO_CYW43_SUPPORTED=0 ; To prevent undefined reference __wrap_cyw43_cb_process_ethernet error from building earlephilhower's lib
    -D CYW43_PIN_WL_DYNAMIC=0 ; To prevent undefined reference __wrap_cyw43_cb_process_ethernet error from building earlephilhower's lib
    
    ;###############################################################
    ; TFT_eSPI library setting here (no need to edit library files):
    ;###############################################################
    -Os
    -D USER_SETUP_LOADED=1
    -D ST7789_DRIVER=1

    -D TFT_WIDTH=240
    -D TFT_HEIGHT=240

    -D TFT_SPI_PORT=1
    -D TFT_MISO=-1
    -D TFT_MOSI=15
    -D TFT_SCLK=14
    -D TFT_CS=-1
    -D TFT_RST=12
    -D TFT_DC=11
    -D TFT_BL=10
    -D TFT_BACKLIGHT_ON=HIGH

    -D LOAD_GLCD=1
    -D LOAD_FONT2=1
    -D LOAD_FONT4=1
    -D LOAD_FONT6=1
    -D LOAD_FONT7=1
    -D LOAD_FONT8=1
    -D LOAD_GFXFF=1
    -D SMOOTH_FONT=1

    -D RP2040_PIO_SPI=1
    -D RP2040_DMA=1

    -D SPI_FREQUENCY=27000000
    -D SPI_READ_FREQUENCY=5000000

Here is the simple code I used to test with TFT_eSPI:

#include <Arduino.h>
#include <TFT_eSPI.h>
#include <SPI.h>

TFT_eSPI tft = TFT_eSPI();

int main()
{
    tft.init();
    // tft.setRotation(1);
    tft.fillScreen(TFT_GREEN);

    while (1)
    {
        tft.fillScreen(TFT_BLUE);
        delay(1000);
        tft.fillScreen(TFT_RED);
        delay(1000);
        tft.fillScreen(TFT_GREEN);
        delay(1000);
        tft.fillScreen(TFT_WHITE);
        delay(1000);
    }

    return 0;
}

I don't know if the setup is correct since I'm pretty new to PIO and somehow my earlephilhower will failed without having PICO_CYW43_SUPPORTED & CYW43_PIN_WL_DYNAMIC set to 0. Any help will be really appreciated! :)

[Basitadam]

Can you give a try with this pin setup:

    -D TFT_SPI_PORT=1
    -D TFT_MISO=-1
    -D TFT_MOSI=11
    -D TFT_SCLK=10
    -D TFT_CS=-1
    -D TFT_RST=12
    -D TFT_DC=9
    -D TFT_BL=14
    -D TFT_BACKLIGHT_ON=HIGH

with reference to RPi official doc:

and Adafruit doc:

[Hraefns]

Sure, thanks for the input. I will retested it again since, actually I commented it out for the last couple test. Right know I'm trying to not use spi.begin() which comes from the framework-aruinopico which seems at first glance to use the deafult CPOL 0 & CPHA 0 but I will try to confirm it, hopefully with custom SPI init it works

[Basitadam]

I am confident that you will figure it out in couple of hours

[Hraefns]

IT'S WORKING NOW!!! Thank you so much so I ended up modifying the TFT_eSPI code I will share it with you tomorrow since it's already late here. But it's working yeah!!!

[Hraefns]

I will need to check a few things, maybe there is a macro( and a reason why it's coded that way) so that I don't need to modify the library itself since my knowledge is still green with TFT and stuff. So I need to be careful

[Basitadam]

Nice work. It didn't even take an hour

[Hraefns]

Okay, I don't find any macro that could be used to fix this but. The fix simply just to modify the TFT_eSPI_RP2040.h just find the macro SET_BUS_READ_MODE and change it into this:
#define SET_BUS_READ_MODE spi_set_format(SPI_X, 8, (spi_cpol_t)(TFT_SPI_MODE >> 1), (spi_cpha_t)(TFT_SPI_MODE & 0x1), SPI_MSB_FIRST)

because if not at the end of each spi transaction (writecommand) it will pull the clock line to SPI MODE 0 (CPOL=0, CPHA=0).

@Basitadam Thank you so much for taking your time to help me, if it wasn't for your help I will still pulling my hairs trying to figure out why the lib doesn't work

[Basitadam]

@Bodmer is currently working on RPi Pico AFAIK. Maybe he can take a look at it.
You are a fine engineer. Now you have a responsibility (you should choose to accept it) to monitor the the page and try to help the other Pico users

[Hraefns]

Sure, I will try to keep an update to the Pico since I'm planning to use this library alongside the LVGL and will try to help others, just like you help me these past few days :D

[TobiasVanDyk]

Maybe this will also help from a few days ago: #3476
Yes, reverting to 2.5.34 works ok. I had a look at the difference between 2.5.34 and 2.5.43 (using WinMerge) to see exactly what has changed. And not much, mostly comment updates. But there is a change to this line in TFT_eSPI_RP2040.h:

2.5.34
#define SET_BUS_READ_MODE // spi_set_format(SPI_X, 8, (spi_cpol_t)0, (spi_cpha_t)0, SPI_MSB_FIRST)

2.5.43
#define SET_BUS_READ_MODE spi_set_format(SPI_X, 8, (spi_cpol_t)0, (spi_cpha_t)0, SPI_MSB_FIRST)

The spi_set_format function has been reinstated. So I updated to 2.5.42 again and commented out that function and now it's working.

Not sure why this is an issue really, it looks like it should be ok using that function. I don't know enough to investigate further. Hoping others can figure it out from here. :)

Cheers, Ian

[Hraefns]

Thank you very much for the info, Tobias. I will definitely try to check that version.