Store and display image with 1BPP

How-to
1

Description

Hi,
I am trying to implement lvgl on a black/white screen.

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

TI CC1354 with TI-RTOS7 and TI Clang v4.0.1.LTS

What LVGL version are you using?

9.2.2

What do you want to achieve?

display 1BPP images stored in flash.

What have you tried so far?

I managed to display some texts using lvgl. Therefore the spi communication to the display as well as lvgl itself seem to be working. I configured LV_COLOR_DEPTH to 1. I also store the images as 1BPP top-down left-right (exactly as the image data needs to be sent to the display controller). I directly sent the image data (const uint8_t image_map) to the display controller and it will be displayed just fine.
the lv_image_dsc_t struct looks like this:
const lv_image_dsc_t StartUpScreen = {
.header.cf = LV_COLOR_FORMAT_I1,
.header.magic = LV_IMAGE_HEADER_MAGIC,
.header.w = 400,
.header.h = 300,
.data_size = 15000,
.data = StartUpScreen_map,
};

Code to reproduce

#include "gui.h"	//LV_IMG_DECLARE for all images
#include "main_tirtos.h"
#include "lvgl/lvgl.h"

#define Source_Pixel        400
#define Gate_Pixel          300
#define Picture_length      Source_Pixel/8*Gate_Pixel   // 400*300/8=15000bytes
#define GUI_BUFFER_SIZE     Picture_length + 8 //2x4 Bytes as palette

static lv_display_t * display1;
static lv_obj_t * active_screen = NULL;

static uint8_t buf1[GUI_BUFFER_SIZE], buf2[GUI_BUFFER_SIZE];    //make sure the horizontal width is 8bit aligned, since LVGL can not handle fractional width

static int GUI_getTicksMs(void)
{
    return (Clock_getTicks() * Clock_tickPeriod / 1000);
}

static void ScreenHandler(void) {
    static int i = 0;
    lv_obj_t *obj;
    int temp;
    char tmp_str[64];
	
	if (active_screen == NULL) {
		active_screen = lv_obj_create(NULL);
		obj = lv_img_create(active_screen);
		lv_img_set_src(obj, &StartUpScreen);
		obj = lv_label_create(active_screen);
		lv_obj_set_width(obj, Source_Pixel);
		lv_label_set_long_mode(obj, LV_LABEL_LONG_WRAP);     /*Break the long lines*/
		sprintf(tmp_str, "APP CC1354\n%s %s", __DATE__, __TIME__);
		lv_label_set_text(obj, tmp_str);
		lv_obj_align(obj, LV_ALIGN_BOTTOM_LEFT, 5, -5);
		lv_screen_load(active_screen);
	}
}

int guiInit(void)
{
    lv_init();

    display1 = lv_display_create(Source_Pixel, Gate_Pixel);
    lv_display_set_buffers(display1, buf1, buf2, GUI_BUFFER_SIZE, LV_DISPLAY_RENDER_MODE_FULL);
    lv_display_set_flush_cb(display1, guiFlushDisplayCB);
    lv_display_set_flush_wait_cb(display1, guiFlushDisplayReadyCB);
	
    return (0);
}

void *guiThread(void *arg0)
{
    int temp;
    int ticks;
    int ticksOld = 0;

    while(1)
    {
        ScreenHandler();
        ticks = GUI_getTicksMs();
        temp = ticks - ticksOld;
        lv_tick_inc(temp);
        ticksOld = ticks;
        temp = lv_timer_handler();
        usleep(temp*1000);	//RTOS function
    }
}

Regards,
Stefan