Having trouble interfacing LVGL with the 1.28inch LCD module GC9A01A display from Waveshare

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Description

What MCU/Processor/Board and compiler are you using?

STM32F411CEU6

What do you want to achieve?

I am trying to use LVGL with the 1.28inch LCB module GC9A01A display.

What have you tried so far?

In my tft.c I have created a simple driver displays which uses the “LCD_1IN28_DrawPaint()” function from the waveshare library “https://www.waveshare.com/wiki/1.28inch_LCD_Module#Resources” to flush the display. The demo spinner kind of appears but there seems to be artifacts as seen in the photo. Does anyone know how I can solve this issue? Thanks!

Code to reproduce

#include "lv_conf.h"
#include "lvgl/lvgl.h"
#include <string.h>
#include <stdlib.h>

#include "tft.h"
#include "Utilities/User/Config/Debug.h"
#include "Utilities/User/Config/DEV_Config.h"
#include "Utilities/User/Fonts/Fonts.h"
#include "Utilities/User/LCD/LCD_1in28.h"
#include "Utilities/User/LCD/Touch_Driver.h"
#include "Utilities/User/GUI_DEV/GUI_Paint.h"

/*********************
 *      DEFINES
 *********************/
#if LV_COLOR_DEPTH != 16 && LV_COLOR_DEPTH != 24 && LV_COLOR_DEPTH != 32
#error LV_COLOR_DEPTH must be 16, 24, or 32
#endif

//Frame buffers
#define BYTES_PER_PIXEL (LV_COLOR_FORMAT_GET_SIZE(LV_COLOR_FORMAT_RGB565)) /*will be 2 for RGB565 */
#define BUFF_SIZE (240 * 10 * BYTES_PER_PIXEL)
static uint8_t buf_1[BUFF_SIZE];
static uint8_t buf_2[BUFF_SIZE];

void ex_disp_flush(lv_display_t * disp, const lv_area_t * area, lv_color_t * color_p);

/**********************
 *  STATIC VARIABLES
 **********************/
#if LV_COLOR_DEPTH == 16
typedef uint16_t uintpixel_t;
#elif LV_COLOR_DEPTH == 24 || LV_COLOR_DEPTH == 32
typedef uint32_t uintpixel_t;
#endif

void tft_init(void)
{

	//Initialise display
	DEV_Module_Init();

	//Set display's brightness
	LCD_1IN28_SetBackLight(1000);

	//Set display's orientation
	LCD_1IN28_Init(VERTICAL);

	lv_display_t * disp = lv_display_create(TFT_HOR_RES, TFT_VER_RES); /*Basic initialization with horizontal and vertical resolution in pixels*/

	static uint8_t buf[TFT_HOR_RES * 68 * 2];


	lv_display_set_buffers(disp, buf_1, buf_2, sizeof(buf_1), LV_DISPLAY_RENDER_MODE_PARTIAL); /* Set an initialized buffer */

	lv_display_set_flush_cb(disp, ex_disp_flush);

}

void ex_disp_flush(lv_display_t * disp, const lv_area_t * area, lv_color_t * color_p)
{
	int32_t x;
    int32_t y;

    for(y = area->y1; y <= area->y2; y++) {
        for(x = area->x1; x <= area->x2; x++) {
        	uint16_t color_full = (color_p->red << 11) | (color_p->green << 5) | (color_p->blue);
        	LCD_1IN28_DrawPaint(x, y, color_full);
        	color_p++;
        }
    }
    lv_display_flush_ready(disp);
}
void tft_test(void)
{
	/* Change Active Screen's background color */
	lv_obj_set_style_bg_color(lv_screen_active(), lv_color_hex(0x003a57), LV_PART_MAIN);
	lv_obj_set_style_text_color(lv_screen_active(), lv_color_hex(0xffffff), LV_PART_MAIN);
	//Create a spinner
	lv_obj_t * spinner = lv_spinner_create(lv_screen_active());
	lv_obj_set_size(spinner, 64, 64);
	lv_obj_align(spinner, LV_ALIGN_CENTER, 0, 0);
}

Screenshot and/or video

lcd prob
lcd prob1200×1600 184 KB

2

Hi,

I think the problem is that in v9 the the last parameter of the flush_cb is an uinr8_t * which is RGB565 already if you set the LV_COLOR_DEPTH 16.

void ex_disp_flush(lv_display_t * disp, const lv_area_t * area, uint8_t * color_p)
{
     int32_t x;
     int32_t y;

    uint16_t * buf16 = (uint16_t *) color_p;
    for(y = area->y1; y <= area->y2; y++) {
        for(x = area->x1; x <= area->x2; x++) {
        	LCD_1IN28_DrawPaint(x, y, *buf16);
        	buf16++;
        }
    }