[National Technology Automotive MCU N32A455 Development Board] SPI screen LVGL transplantation

尹小舟

[National Technology Automotive MCU N32A455 Development Board] SPI screen LVGL transplantation [Copy link]

1. Simplify LVGL source code

Except for the examples folder, src folder, lv_conf_template.h and lvgl.h files, all other files can be deleted.

lv_conf_template.h was changed to lv_conf.h.

2 Add files to the project

2.1 Create a new LVGL related folder

2.2 Adding groups in MDK

Create the following group in MDK

LVGL/exanples/porting

LVGL/src/core

LVGL/src/draw

LVGL/src/extra

LVGL/src/font

LVGL/src/gpu

LVGL/src/hal

LVGL/src/misc

LVGL/src/widgets

Adding files from LVGL

3 Adaptation of LVGL related interfaces

3.1 LVGL time base adaptation

Use a timer to set a 1MS interrupt

Create a new tim_delay_ms.c and implement a TIM3 timing 1ms interrupt function in it.

#include "tim_delay_ms.h"
#include "lvgl.h"


/**
 * [url=home.php?mod=space&uid=159083]@brief[/url]  Timer3 initialization configuration.
 */
void tim3_init(uint16_t Period, uint16_t Prescaler)
{
    TIM_TimeBaseInitType timInitStruct;
    NVIC_InitType NVIC_InitStructure;

    RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_TIM3, ENABLE);

    timInitStruct.Period    = Period;
    timInitStruct.Prescaler = Prescaler;
    timInitStruct.ClkDiv    = 0;
    timInitStruct.CntMode   = TIM_CNT_MODE_UP;
    TIM_InitTimeBase(TIM3, &timInitStruct);

    TIM_ConfigInt(TIM3, TIM_INT_UPDATE, ENABLE);

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    NVIC_InitStructure.NVIC_IRQChannel                   = TIM3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    TIM_Enable(TIM3, ENABLE);
}

/**
  * @brief  TIM3 interrupt process function each 100us.Get the TIM2->CNT value, and Calculate the number of pulses by
  the difference of two times. Then take the delta pules into the buffer of last channel and toggle to new channel.
  */
void TIM3_IRQHandler(void)
{
    if (TIM_GetIntStatus(TIM3, TIM_INT_UPDATE) != RESET)
    {
        TIM_ClrIntPendingBit(TIM3, TIM_INT_UPDATE);
        
         lv_tick_inc(1); /* lvgl 的 1ms 心跳 */     
    }
}

Timing header file

#ifndef __TIM_DELAY_H__
#define __TIM_DELAY_H__


#include "n32a455.h"

void tim3_init(uint16_t Period, uint16_t Prescaler);

#endif

3.2 Display driver configuration

3.2.1 To modify two macros, set the resolution

#define MY_DISP_HOR_RES 320

#define MY_DISP_VER_RES 480

3.2.2 Add LCD initialization function

static void disp_init(void)

{

LCD_Init();

}

3..2.3 Adaptation management function

static void disp_flush(lv_disp_drv_t * disp_drv, const lv_area_t * area, lv_color_t * color_p)
{
    if(disp_flush_enabled) {
        /*The most simple case (but also the slowest) to put all pixels to the screen one-by-one*/

        int32_t x;
        int32_t y;
        for(y = area->y1; y <= area->y2; y++) {
            for(x = area->x1; x <= area->x2; x++) {
                /*Put a pixel to the display. For example:*/
                /*put_px(x, y, *color_p)*/
            GUI_DrawPoint(x, y,color_p->full);
                color_p++;
            }
        }
    }

    /*IMPORTANT!!!
     *Inform the graphics library that you are ready with the flushing*/
    lv_disp_flush_ready(disp_drv);
}

Here is the GUI_DrawPoint parameter:

void GUI_DrawPoint(unsigned short x,unsigned short y,unsigned short color)

color_p is a structure pointer

typedef union {
    struct {
#if LV_COLOR_16_SWAP == 0
        uint16_t blue : 5;
        uint16_t green : 6;
        uint16_t red : 5;
#else
        uint16_t green_h : 3;
        uint16_t red : 5;
        uint16_t blue : 5;
        uint16_t green_l : 3;
#endif
    } ch;
    uint16_t full;
} lv_color16_t;

lv_color16_t is a union, so you can directly fill color_p->full

/**
 * [url=home.php?mod=space&uid=1307177]@File[/url]  lv_port_disp_templ.c
 *
 */

/*Copy this file as "lv_port_disp.c" and set this value to "1" to enable content*/
#if 1

/*********************
 *      INCLUDES
 *********************/
#include "lv_port_disp_template.h"
#include <stdbool.h>
#include <stdio.h>
/*********************
 *      DEFINES
 *********************/
#ifndef MY_DISP_HOR_RES
    #warning Please define or replace the macro MY_DISP_HOR_RES with the actual screen width, default value 320 is used for now.
    #define MY_DISP_HOR_RES    320
#endif

#ifndef MY_DISP_VER_RES
    #warning Please define or replace the macro MY_DISP_HOR_RES with the actual screen height, default value 240 is used for now.
    #define MY_DISP_VER_RES    480
#endif

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

/**********************
 *  STATIC PROTOTYPES
 **********************/
static void disp_init(void);

static void disp_flush(lv_disp_drv_t * disp_drv, const lv_area_t * area, lv_color_t * color_p);
//static void gpu_fill(lv_disp_drv_t * disp_drv, lv_color_t * dest_buf, lv_coord_t dest_width,
//        const lv_area_t * fill_area, lv_color_t color);

/**********************
 *  STATIC VARIABLES
 **********************/

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

/**********************
 *   GLOBAL FUNCTIONS
 **********************/

void lv_port_disp_init(void)
{
    /*-------------------------
     * Initialize your display
     * -----------------------*/
//    disp_init();
     LCD_Init();
    /*-----------------------------
     * Create a buffer for drawing
     *----------------------------*/

    /**
     * LVGL requires a buffer where it internally draws the widgets.
     * Later this buffer will passed to your display driver's `flush_cb` to copy its content to your display.
     * The buffer has to be greater than 1 display row
     *
     * There are 3 buffering configurations:
     * 1. Create ONE buffer:
     *      LVGL will draw the display's content here and writes it to your display
     *
     * 2. Create TWO buffer:
     *      LVGL will draw the display's content to a buffer and writes it your display.
     *      You should use DMA to write the buffer's content to the display.
     *      It will enable LVGL to draw the next part of the screen to the other buffer while
     *      the data is being sent form the first buffer. It makes rendering and flushing parallel.
     *
     * 3. Double buffering
     *      Set 2 screens sized buffers and set disp_drv.full_refresh = 1.
     *      This way LVGL will always provide the whole rendered screen in `flush_cb`
     *      and you only need to change the frame buffer's address.
     */

    /* Example for 1) */
    static lv_disp_draw_buf_t draw_buf_dsc_1;
    static lv_color_t buf_1[MY_DISP_HOR_RES * 10];                          /*A buffer for 10 rows*/
    lv_disp_draw_buf_init(&draw_buf_dsc_1, buf_1, NULL, MY_DISP_HOR_RES * 10);   /*Initialize the display buffer*/

//    /* Example for 2) */
//    static lv_disp_draw_buf_t draw_buf_dsc_2;
//    static lv_color_t buf_2_1[MY_DISP_HOR_RES * 10];                        /*A buffer for 10 rows*/
//    static lv_color_t buf_2_2[MY_DISP_HOR_RES * 10];                        /*An other buffer for 10 rows*/
//    lv_disp_draw_buf_init(&draw_buf_dsc_2, buf_2_1, buf_2_2, MY_DISP_HOR_RES * 10);   /*Initialize the display buffer*/

//    /* Example for 3) also set disp_drv.full_refresh = 1 below*/
//    static lv_disp_draw_buf_t draw_buf_dsc_3;
//    static lv_color_t buf_3_1[MY_DISP_HOR_RES * MY_DISP_VER_RES];            /*A screen sized buffer*/
//    static lv_color_t buf_3_2[MY_DISP_HOR_RES * MY_DISP_VER_RES];            /*Another screen sized buffer*/
//    lv_disp_draw_buf_init(&draw_buf_dsc_3, buf_3_1, buf_3_2,
//                          MY_DISP_VER_RES * LV_VER_RES_MAX);   /*Initialize the display buffer*/

    /*-----------------------------------
     * Register the display in LVGL
     *----------------------------------*/

    static lv_disp_drv_t disp_drv;                         /*Descriptor of a display driver*/
    lv_disp_drv_init(&disp_drv);                    /*Basic initialization*/

    /*Set up the functions to access to your display*/

    /*Set the resolution of the display*/
    disp_drv.hor_res = MY_DISP_HOR_RES;
    disp_drv.ver_res = MY_DISP_VER_RES;

    /*Used to copy the buffer's content to the display*/
    disp_drv.flush_cb = disp_flush;

    /*Set a display buffer*/
    disp_drv.draw_buf = &draw_buf_dsc_1;

    /*Required for Example 3)*/
    //disp_drv.full_refresh = 1;

    /* Fill a memory array with a color if you have GPU.
     * Note that, in lv_conf.h you can enable GPUs that has built-in support in LVGL.
     * But if you have a different GPU you can use with this callback.*/
    //disp_drv.gpu_fill_cb = gpu_fill;

    /*Finally register the driver*/
    lv_disp_drv_register(&disp_drv);
}

/**********************
 *   STATIC FUNCTIONS
 **********************/

/*Initialize your display and the required peripherals.*/
static void disp_init(void)
{
    /*You code here*/
      LCD_Init();
}

volatile bool disp_flush_enabled = true;

/* Enable updating the screen (the flushing process) when disp_flush() is called by LVGL
 */
void disp_enable_update(void)
{
    disp_flush_enabled = true;
}

/* Disable updating the screen (the flushing process) when disp_flush() is called by LVGL
 */
void disp_disable_update(void)
{
    disp_flush_enabled = false;
}

/*Flush the content of the internal buffer the specific area on the display
 *You can use DMA or any hardware acceleration to do this operation in the background but
 *'lv_disp_flush_ready()' has to be called when finished.*/
static void disp_flush(lv_disp_drv_t * disp_drv, const lv_area_t * area, lv_color_t * color_p)
{
    if(disp_flush_enabled) {
        /*The most simple case (but also the slowest) to put all pixels to the screen one-by-one*/

        int32_t x;
        int32_t y;
        for(y = area->y1; y <= area->y2; y++) {
            for(x = area->x1; x <= area->x2; x++) {
                /*Put a pixel to the display. For example:*/
                /*put_px(x, y, *color_p)*/
                              GUI_DrawPoint(x, y,color_p->full);
                color_p++;
            }
        }
    }

    /*IMPORTANT!!!
     *Inform the graphics library that you are ready with the flushing*/
    lv_disp_flush_ready(disp_drv);
}

/*OPTIONAL: GPU INTERFACE*/

/*If your MCU has hardware accelerator (GPU) then you can use it to fill a memory with a color*/
//static void gpu_fill(lv_disp_drv_t * disp_drv, lv_color_t * dest_buf, lv_coord_t dest_width,
//                    const lv_area_t * fill_area, lv_color_t color)
//{
//    /*It's an example code which should be done by your GPU*/
//    int32_t x, y;
//    dest_buf += dest_width * fill_area->y1; /*Go to the first line*/
//
//    for(y = fill_area->y1; y <= fill_area->y2; y++) {
//        for(x = fill_area->x1; x <= fill_area->x2; x++) {
//            dest_buf[x] = color;
//        }
//        dest_buf+=dest_width;    /*Go to the next line*/
//    }
//}


#else /*Enable this file at the top*/

/*This dummy typedef exists purely to silence -Wpedantic.*/
typedef int keep_pedantic_happy;
#endif

4.main file

Initialization requires calling lv_init(); and in while, calling lv_timer_handler(), the LVGL timer.

/**
 * @brief   Main program
 */
int main(void)
{
    /* System clocks configuration ---------------------------------------------*/
   RCC_Configuration();
   uart_print_init();     
   TIM_Configuration();    
   lv_init(); 
   lv_port_disp_init();
   lv_obj_t *label = lv_label_create(lv_scr_act());
   lv_label_set_text(label,"Hello Alientek!!!");
   lv_obj_center(label);
    while (1)
    {
                 lv_timer_handler(); /* LVGL计时器 */
        
    }
}

5 Download

The main frequency is 144, and the SPI2/SPI3 interface is only 18Mbps

Some hot melt glue

My speed reading is so slow, I am optimizing it.

lugl4313820

It will be good if it runs. My SPI hardware is not running yet. Can you share the source code of your work?