Driver for 3.5inch RPi Display (MPI3501) about lv_port_esp32

[C47D]

Hi,

Great, I should add a contribution guide to add support for drivers, it's a easy but laborious process.
I think is best if we add the support for the ILI9486 controller and add the MPI3501 as predefined display, what do you think?

To do so:

1. In components/lvgl_esp32_drivers/lvgl_tft/ copy ili9341.h and rename it after the display controller, so ili9486.h, replace the text ILI9341 with ILI9486, this is the bare minimal, you can add register definitions, etc. it will end up something like this:

#ifndef ILI9486_H
#define ILI9486_H

#ifdef __cplusplus
extern "C" {
#endif

/*********************
 *      INCLUDES
 *********************/
#include <stdbool.h>

#include "lvgl/lvgl.h"

/*********************
 *      DEFINES
 *********************/
#define DISP_BUF_SIZE (LV_HOR_RES_MAX * 40)
#define ILI9486_DC   CONFIG_LVGL_DISP_PIN_DC
#define ILI9486_RST  CONFIG_LVGL_DISP_PIN_RST
#define ILI9486_BCKL CONFIG_LVGL_DISP_PIN_BCKL

#define ILI9486_ENABLE_BACKLIGHT_CONTROL CONFIG_LVGL_ENABLE_BACKLIGHT_CONTROL

#if CONFIG_LVGL_BACKLIGHT_ACTIVE_LVL
  #define ILI9486_BCKL_ACTIVE_LVL 1
#else
  #define ILI9486_BCKL_ACTIVE_LVL 0
#endif

// if text/images are backwards, try setting this to 1
#define ILI9486_INVERT_DISPLAY CONFIG_LVGL_INVERT_DISPLAY

/**********************
 *      TYPEDEFS
 **********************/

/**********************
 * GLOBAL PROTOTYPES
 **********************/

void ili9486_init(void);
void ili9486_flush(lv_disp_drv_t * drv, const lv_area_t * area, lv_color_t * color_map);
void ili9486_enable_backlight(bool backlight);

/**********************
 *      MACROS
 **********************/


#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /*ILI9486_H*/

2. Same for the c file, copy ili9341.c and rename it to ili9486.c, rename the functions init, flush and enable_backlight so they start with ili9486. Also rename all the ILI9341 references to ILI9486.
   Edit the functions so they match your init configuration sequence, flush function.

3. Open disp_driver.h and edit it so it end up like this:

/*********************
 *      INCLUDES
 *********************/
#include <stdbool.h>
#include "lvgl/lvgl.h"
#include "ili9341.h"
#include "ili9488.h"
#include "st7789.h"
#include "hx8357.h"
#include "ili9486.h"

/*********************
 *      DEFINES
 *********************/
 /* Add a new define entry at the end for new controllers */
#define TFT_CONTROLLER_ILI9341  0
#define TFT_CONTROLLER_ILI9488  1
#define TFT_CONTROLLER_ST7789	2
#define TFT_CONTROLLER_HX8357   3
#define TFT_CONTROLLER_ILI9486  4

4. Edit disp_driver.c and add the init and flush functions of your display:

void disp_driver_init(bool init_spi)
{
	if (init_spi) {
		disp_spi_init();
	}
	
#if CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ILI9341
    ili9341_init();
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ILI9488
    ili9488_init();
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ST7789
    st7789_init();
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_HX8357
	hx8357_init(HX8357D);
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ILI9486
    ili9486_init();
#endif
}

void disp_driver_flush(lv_disp_drv_t * drv, const lv_area_t * area, lv_color_t * color_map)
{
#if CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ILI9341
    ili9341_flush(drv, area, color_map);
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ILI9488
    ili9488_flush(drv, area, color_map);
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ST7789
    st7789_flush(drv, area, color_map);
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_HX8357
	hx8357_flush(drv, area, color_map);
#elif CONFIG_LVGL_TFT_DISPLAY_CONTROLLER == TFT_CONTROLLER_ILI9486
	ili9486_flush(drv, area, color_map);
#endif
}

5. In disp_spi.c you can edit the spi_bus_config_t and spi_device_interface_config_t struct members if the ili9486 can handle higher spi clock or spi mode, you can see the current implementation and add the necesary code easily.

6. Open the Kconfig file and add the necessary code so it end up like this:

    choice LVGL_PREDEFINED_DISPLAY
        prompt "Select predefined display configuration"
        default LVGL_PREDEFINED_DISPLAY_NONE
        help
            Select predefined display configuration

        config LVGL_PREDEFINED_DISPLAY_NONE
            bool "None"
        config LVGL_PREDEFINED_DISPLAY_WROVER4
            bool "ESP-Wrover-KIT v4.1"
        config LVGL_PREDEFINED_DISPLAY_M5STACK
            bool "M5Stack"
	config LVGL_PREDEFINED_DISPLAY_ERTFT0356
	    bool "ER-TFT035-6"
	config LVGL_PREDEFINED_DISPLAY_ADA_FEATHERWING
	    bool "Adafruit 3.5 Featherwing"
	config LVGL_PREDEFINED_DISPLAY_MPI3501
	    bool "Raspberry Pi MPI3501"
    endchoice

    config LVGL_TFT_DISPLAY_CONTROLLER
	int
	default 0 if LVGL_TFT_DISPLAY_CONTROLLER_ILI9341
	default 1 if LVGL_TFT_DISPLAY_CONTROLLER_ILI9488 || LVGL_PREDEFINED_DISPLAY_ERTFT0356
	default 2 if LVGL_TFT_DISPLAY_CONTROLLER_ST7789
	default 3 if LVGL_TFT_DISPLAY_CONTROLLER_HX8357
        default 4 if LVGL_TFT_DISPLAY_CONTROLLER_ILI9486

	choice
	    prompt "Select a display controller model." if LVGL_PREDEFINED_DISPLAY_NONE
	    default LVGL_TFT_DISPLAY_CONTROLLER_ILI9341
	    default LVGL_TFT_DISPLAY_CONTROLLER_ILI9341 if LVGL_PREDEFINED_DISPLAY_WROVER4
	    default LVGL_TFT_DISPLAY_CONTROLLER_ILI9341 if LVGL_PREDEFINED_DISPLAY_M5STACK
	    default LVGL_TFT_DISPLAY_CONTROLLER_ILI9488 if LVGL_PREDEFINED_DISPLAY_ERTFT0356
	    default LVGL_TFT_DISPLAY_CONTROLLER_HX8357 if LVGL_PREDEFINED_DISPLAY_ADA_FEATHERWING
	    default LVGL_TFT_DISPLAY_CONTROLLER_ILI9486 if LVGL_PREDEFINED_DISPLAY_MPI3501
	    
	    help
		Select the controller for your display.

	    config LVGL_TFT_DISPLAY_CONTROLLER_ILI9341
		bool "ILI9341"
	    config LVGL_TFT_DISPLAY_CONTROLLER_ILI9488
		bool "ILI9488"
	    config LVGL_TFT_DISPLAY_CONTROLLER_ST7789
		bool "ST7789"
	    config LVGL_TFT_DISPLAY_CONTROLLER_HX8357
		bool "HX8357"
	    config LVGL_TFT_DISPLAY_CONTROLLER_ILI9486
		bool "ILI9486"
	endchoice

Then edit the LVGL_DISPLAY_WIDTH and LVGL_DISPLAY_HEIGHT with the size of the display, replace the XXX with the actual numbers:

    config LVGL_DISPLAY_WIDTH
        int "TFT display width in pixels." if LVGL_PREDEFINED_DISPLAY_NONE
        default 240 if LVGL_PREDEFINED_DISPLAY_M5STACK
	default 480 if LVGL_PREDEFINED_DISPLAY_ERTFT0356 || LVGL_PREDEFINED_DISPLAY_ADA_FEATHERWING
        default XXX if LVGL_PREDEFINED_DISPLAY_MPI3501
	default 320

    config LVGL_DISPLAY_HEIGHT
        int "TFT display height in pixels." if LVGL_PREDEFINED_DISPLAY_NONE
        default 320 if LVGL_PREDEFINED_DISPLAY_M5STACK || LVGL_PREDEFINED_DISPLAY_ERTFT0356 || LVGL_PREDEFINED_DISPLAY_ADA_FEATHERWING
        default XXX if LVGL_PREDEFINED_DISPLAY_MPI3501
        default 240

If the display have a backlight enable pin edit the LVGL_ENABLE_BACKLIGHT_CONTROL config, add a field for the LVGL_PREDEFINED_DISPLAY_MPI3501 as we did with the width and heigth before.

I think that's everything you need to do, please let me know if you have any questions.

[ndunello]

Hi @C47D,
thank you very much for the detailed explanation.
I had already made the changes you indicated.
This is the output of the git status command:

On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   components/lv_examples/lv_ex_conf.h
        modified:   components/lvgl/lv_conf.h
        modified:   components/lvgl_esp32_drivers/lvgl_driver.c
        modified:   components/lvgl_esp32_drivers/lvgl_tft/Kconfig
        modified:   components/lvgl_esp32_drivers/lvgl_tft/disp_driver.c
        modified:   components/lvgl_esp32_drivers/lvgl_tft/disp_driver.h
        modified:   components/lvgl_esp32_drivers/lvgl_tft/disp_spi.c
        modified:   components/lvgl_esp32_drivers/lvgl_touch/xpt2046.c
        modified:   sdkconfig

Untracked files:
  (use "git add <file>..." to include in what will be committed)
        .project
        components/lvgl_esp32_drivers/lvgl_tft/mpi3501.c
        components/lvgl_esp32_drivers/lvgl_tft/mpi3501.h

no changes added to commit (use "git add" and/or "git commit -a")

Also I created mpi3501.c and mpi3501.h in components\lvgl_esp32_drivers\lvgl_tft directory.
So I wanted to know how to publish the changes for the community. I'm novice with the git :-(
Do I have to send you an email with the patch file?

Ciao

[C47D]

I can help you to create a pull request if you want, or if you prefer you can send me your files, my mail is in my user main page.

To create a pull request:
you need to move those changes into a new branch, go to where youre working on, then create a new branch:

git checkout -b rpi_display

Add all the edited files:

git add .

Then remove the sdkconfig from the staging area:

git reset sdkconfig

Do a commit:

git commit -m "Initial support for MPI3501"

Then push the commit to your fork:

git push origin rpi_display

Go to your fork and you will see a button to create a pull request with your additions into this repo, click it and that should be it.

[ndunello]

I tried with the pull request, but the last command fails!

git status
On branch rpi_display
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   components/lv_examples/lv_ex_conf.h
        modified:   components/lvgl/lv_conf.h
        modified:   components/lvgl_esp32_drivers/lvgl_driver.c
        modified:   components/lvgl_esp32_drivers/lvgl_tft/Kconfig
        modified:   components/lvgl_esp32_drivers/lvgl_tft/disp_driver.c
        modified:   components/lvgl_esp32_drivers/lvgl_tft/disp_driver.h
        modified:   components/lvgl_esp32_drivers/lvgl_tft/disp_spi.c
        modified:   components/lvgl_esp32_drivers/lvgl_touch/xpt2046.c
        modified:   sdkconfig

Untracked files:
  (use "git add <file>..." to include in what will be committed)
        .project
        add_mpi3501_support.patch

no changes added to commit (use "git add" and/or "git commit -a")

C:\projects\esp32\lv_port_esp32>git push origin rpi_display
remote: Permission to littlevgl/lv_port_esp32.git denied to ndunello.
fatal: unable to access 'https://github.com/littlevgl/lv_port_esp32.git/': The requested URL returned error: 403

I sent you an email with the patch of the modified files and the new files.
Thanks

[C47D]

Hi,

Just checked my email and I don't see your email, did you sent the email to [email protected]?

[embeddedt]

@ndunello You tried to push to https://github.com/littlevgl/lv_port_esp32 (which you don't have write access to). You need to fork that repository, clone the fork, and apply your changes there.

Here's the blog post we routinely link to for the main LittlevGL repository. The process is basically identical except you want to clone lv_port_esp32 instead of lvgl.

[ndunello]

the pins that I used for the connection are the following (shared spi):
display

• MISO 19
• MOSI 23
• CLK 18
• CS 15
• DC 2
• RST 4

touch

• MISO 19
• MOSI 23
• CLK 18
• CS 22
• IRQ 25

the display maybe has some problems

I also attach the pinout of the display hoping it will be useful

[C47D]

Thanks for the information @ndunello, I will update the README with it :)